Simple spectrum analyzer for pre-compliance

[Joerg]

Hello Folks,

Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.

The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

[Paul Mathews]

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).
--
Regards, Joerg
http://www.analogconsultants.com

I use HP859x series of spectrum analyzers, particularly 8591EM if
available. For an interface, I use Nat'l Instruments ENET, which
converts the GPIB port to 10BaseT. The spectrum analyzer then has a
LAN address, and relatively simple commands sent via the NI GPIB layer
suffice to control the instrument and exchange data. Instead of using
LabView, for example, I wrote a VB6 app to make it easier to store and
compare traces, subtract baselines, etc. Not a straightforward
approach, I'll admit, but it does the job. I'm quite fond of these
old HP SAs.
Paul Mathews

[Joerg]

Post by Paul Mathews

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).
--
Regards, Joerg
http://www.analogconsultants.com

I use HP859x series of spectrum analyzers, particularly 8591EM if
available. For an interface, I use Nat'l Instruments ENET, which
converts the GPIB port to 10BaseT. The spectrum analyzer then has a
LAN address, and relatively simple commands sent via the NI GPIB layer
suffice to control the instrument and exchange data. Instead of using
LabView, for example, I wrote a VB6 app to make it easier to store and
compare traces, subtract baselines, etc. Not a straightforward
approach, I'll admit, but it does the job. I'm quite fond of these
old HP SAs.

Looked on Ebay, none there :-(

But I am not a fan of those GPIB garden hose connections. Best would be
something simple. Small box plus USB cable, just like the new DSOs.

[Joel Kolstad]

Post by Paul Mathews
I use HP859x series of spectrum analyzers, particularly 8591EM if
available.... I'm quite fond of these
old HP SAs.

Don't they have "instrument BASIC" built-in? I.e., you can write all sorts of
data processing programs write on the instrument itself if you don't have a PC
handy? Granted, these days that's unlikely, but in many ways it seems that
those older instruments had more features than some of the new models!

[krw]

Post by Paul Mathews

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).
--
Regards, Joerg
http://www.analogconsultants.com

I use HP859x series of spectrum analyzers, particularly 8591EM if
available. For an interface, I use Nat'l Instruments ENET, which
converts the GPIB port to 10BaseT. The spectrum analyzer then has a
LAN address, and relatively simple commands sent via the NI GPIB layer
suffice to control the instrument and exchange data. Instead of using
LabView, for example, I wrote a VB6 app to make it easier to store and
compare traces, subtract baselines, etc. Not a straightforward
approach, I'll admit, but it does the job. I'm quite fond of these
old HP SAs.

I second the recommendation for the 809x analyzers. I bought one
several years ago and sobbed when they sent it and the calibrated
antennas out to scrap a year later. :-(
'
'
--
Keith

[David L. Jones]

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Why not try photographing the screen with a digital camera?
I've done this many times on gear that doesn't have output capability.
Results have ranged from crappy but usable to excellent. Never as good
as a direct screen dump to a USB stick, but good enough for most
documentation purposes.
A slow shutter speed is the go to avoid screen refresh problems etc. A
mini tripod or Farnell catalog or two works a treat to keep it steady.

Dave.

[Joerg]

Post by David L. Jones

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Why not try photographing the screen with a digital camera?
I've done this many times on gear that doesn't have output capability.
Results have ranged from crappy but usable to excellent. Never as good
as a direct screen dump to a USB stick, but good enough for most
documentation purposes.
A slow shutter speed is the go to avoid screen refresh problems etc. A
mini tripod or Farnell catalog or two works a treat to keep it steady.

I am doing that right now. However, this gets old when you have to scale
for a bumpy antenna gain curve.

[Jeff Liebermann]

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
plotter emulators available:
<http://www.fplot.com>
<http://www.printcapture.com>

I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.

One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

[Joerg]

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

[RST Engineering (jw)]

OK, you're lazy. {;-)

Did your friend in the investment game get sufficient answers from the dean
of my department that runs the business department? I saw one answer that
said he had to have a masters to teach that particular subject and saw no
more correspondence.

The only exception to that requirement for a masters is teaching
Career/Technical Ed (what we used to call VocEd) such as welding, woodwork,
electronics technology, and the like where a simple bachelor's in any field
and X years working in the field. X is a function of subject and level.

Jim

Post by Joerg
Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".
--
Regards, Joerg
http://www.analogconsultants.com

[Joerg]

Post by RST Engineering (jw)
OK, you're lazy. {;-)

Well, let's call it spoiled by a new DSO. Plugged it in, loaded their SW
and bingo. Now I wish there was an easier method to get live pics in
Excel. How is it than mankind always wants more?

Post by RST Engineering (jw)
Did your friend in the investment game get sufficient answers from the dean
of my department that runs the business department? I saw one answer that
said he had to have a masters to teach that particular subject and saw no
more correspondence.

Haven't talked to him in a week, we usually see them during some of our
dog walks. After your correspondence we had them over for a dinner and
he was really thankful for your help.

Post by RST Engineering (jw)
The only exception to that requirement for a masters is teaching
Career/Technical Ed (what we used to call VocEd) such as welding, woodwork,
electronics technology, and the like where a simple bachelor's in any field
and X years working in the field. X is a function of subject and level.

Why are they keeping such artificial barriers? In my case I'd have the
masters but I bet they'd find a hair in the soup because it's from a
foreign country, albeit formally blessed by the US goverment. One thing
I really dislike about IEEE is that some of my dues go to their ABET
"efforts". I am a firm believer in academia being able to decide on
their own who is good and who isn't, no need for ever more bureaucratic
hurdles.

[Jeff Liebermann]

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Well, there are spectrum analyzers that have the tradition mess of BNC
connectors on the back, which usually include something to drive a pen
plotter. They're usually labelled X, Y, and pen lift. You can
probably do something useful with that. XY pen plotters can still be
found, or just use your DSO.

Post by Joerg

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

You're lazy, but such laziness has been the inspiration behind some of
my best ideas. Don't let it bother you (much).

How about a compromise? Instead of a USB stick, one of the ever
growing variety of memory cards that are being used in digital cameras
will probably suffice. Build a cardboard or foam board hood and mount
the camera at the correct location. Make it fairly long (about 0.8
meters) so that you don't have a depth of field problem, where the
focus is different in the display center and at the edges. Pre-focus
and set the zoom. Paint the hood black inside. When the display has
something that's worth capturing, push the shutter button. Clean up
the picture with Photoshop or Irfanview.

If dealing with the memory card is too much for you, run a USB cable
to the camera, and capture the image directly on your PC. The only
problem with this approach is that the "video" mode on most cheap
digital cameras is 320x240 or 640x480 at best. That may not be enough
for a detailed photo. However, I've seen spectrum analyzer photos on
FCC type certification documents that look like they were frame
grabbed from a video camera, so this method is probably suitable for
pre-certification.

[Joerg]

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Well, there are spectrum analyzers that have the tradition mess of BNC
connectors on the back, which usually include something to drive a pen
plotter. They're usually labelled X, Y, and pen lift. You can
probably do something useful with that. XY pen plotters can still be
found, or just use your DSO.

The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

You're lazy, but such laziness has been the inspiration behind some of
my best ideas. Don't let it bother you (much).
How about a compromise? Instead of a USB stick, one of the ever
growing variety of memory cards that are being used in digital cameras
will probably suffice. Build a cardboard or foam board hood and mount
the camera at the correct location. Make it fairly long (about 0.8
meters) so that you don't have a depth of field problem, where the
focus is different in the display center and at the edges. Pre-focus
and set the zoom. Paint the hood black inside. When the display has
something that's worth capturing, push the shutter button. Clean up
the picture with Photoshop or Irfanview.
If dealing with the memory card is too much for you, run a USB cable
to the camera, and capture the image directly on your PC. The only
problem with this approach is that the "video" mode on most cheap
digital cameras is 320x240 or 640x480 at best. That may not be enough
for a detailed photo. However, I've seen spectrum analyzer photos on
FCC type certification documents that look like they were frame
grabbed from a video camera, so this method is probably suitable for
pre-certification.

That's how I do it now. Would be nice if I didn't have to ;-)

But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment". Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."

[Jeff Liebermann]

Post by Joerg
The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Connect it to the Z axis input (trace inhibit) of your DSO.

Post by Joerg
That's how I do it now. Would be nice if I didn't have to ;-)

You don't have to. You can hire someone to do it for you.

Perhaps hire an artist have have them sketch the display?

Post by Joerg
But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.

You'll be amazed at how quickly they learn after you explain that
their job, life, future, and salary depend on their ability to operate
the device. No rush, take all night if you need to.

Post by Joerg
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment".

I have a camcorder for such exercises. I've video taped how I setup a
rather messy rack full of acronyms before it was shipped. On arrival,
the techs followed the video religiously, including purchasing a trash
can to match the one I accidentally left in the video. Immitation
works amazingly well, even with little thinking involved.

Incidentally, I intentionally delayed the shipment of the manuals so
that they had to follow the video and could not get creative. The
problems started immediately after the manuals arrived, when the
tweaks, adjustments, and "calibration" began.

Post by Joerg
Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."

You really are lazy. Pry yourself out of your overstuffed easy chair,
get up, and go look at the spectrum analzyer display. Then tell the
tech to make the changes. Think paperless office or save a tree. When
you're happy, say "print it" and do the photographic ordeal process.

[Joerg]

Post by Jeff Liebermann

Post by Joerg
The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Connect it to the Z axis input (trace inhibit) of your DSO.

I am afraid it doesn't have that function. Unless it's thoroughly hidden
somewhere.

Post by Jeff Liebermann

Post by Joerg
That's how I do it now. Would be nice if I didn't have to ;-)

You don't have to. You can hire someone to do it for you.
Perhaps hire an artist have have them sketch the display?

Hmm, I might not even have to, my wife is pretty good at pencil
drawings. Now I'd just have to cajole that pulse noise into sitting
still for 10 minutes or so.

Post by Jeff Liebermann

Post by Joerg
But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.

You'll be amazed at how quickly they learn after you explain that
their job, life, future, and salary depend on their ability to operate
the device. No rush, take all night if you need to.

:-)

Post by Jeff Liebermann

Post by Joerg
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment".

I have a camcorder for such exercises. I've video taped how I setup a
rather messy rack full of acronyms before it was shipped. On arrival,
the techs followed the video religiously, including purchasing a trash
can to match the one I accidentally left in the video. Immitation
works amazingly well, even with little thinking involved.
Incidentally, I intentionally delayed the shipment of the manuals so
that they had to follow the video and could not get creative. The
problems started immediately after the manuals arrived, when the
tweaks, adjustments, and "calibration" began.

Post by Joerg
Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."

You really are lazy. Pry yourself out of your overstuffed easy chair,
get up, and go look at the spectrum analzyer display. Then tell the
tech to make the changes. Think paperless office or save a tree. When
you're happy, say "print it" and do the photographic ordeal process.

There remains a wee problem though: I am a consultant and the engineers
I am talking to are anywhere from 25 miles to 6000 miles from here. We
do have a runway right in town and my office is next to it but I haven't
found the matching LearJet on EBay yet.

[Jeff Liebermann]

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Connect it to the Z axis input (trace inhibit) of your DSO.

I am afraid it doesn't have that function. Unless it's thoroughly hidden
somewhere.

Sigh. What manner of DSO is this? Without an analog Z axis input,
it's not possible to use the scope as a video display for watching TV
during working hours.

Post by Joerg

Post by Jeff Liebermann
Perhaps hire an artist have have them sketch the display?

Hmm, I might not even have to, my wife is pretty good at pencil
drawings. Now I'd just have to cajole that pulse noise into sitting
still for 10 minutes or so.

Tell her it's good training for catching moving artisitic subjects and
speed sketching. However, that will work only long enough for her to
realize she's been tricked. Methinks it would be easier and safer to
teach your jr engineer or tech to sketch.

Post by Joerg
There remains a wee problem though: I am a consultant and the engineers
I am talking to are anywhere from 25 miles to 6000 miles from here. We
do have a runway right in town and my office is next to it but I haven't
found the matching LearJet on EBay yet.

Telepresence and Waldo. There are major strides being made in robotic
remote manipulation and visulization. Just build a robotic clone of
yourself and install it at the customers. If the medical profession
can do surgery over the internet, you can easily run a remote spectrum
analyzer. Operate it from your overstuffed easy chair. Not only can
you do the pre-compliance qualification, but you can also intimidate
the customer into paying the bill.
<http://en.wikipedia.org/wiki/Waldo_%28short_story%29>
<http://en.wikipedia.org/wiki/Telepresence>

If that's too much, get a GPIB to ethernet adapter, plug it into the
customers network, and run the spectrum analyzer yourself via the
internet.

[Joerg]

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Connect it to the Z axis input (trace inhibit) of your DSO.

I am afraid it doesn't have that function. Unless it's thoroughly hidden
somewhere.

Sigh. What manner of DSO is this? Without an analog Z axis input,
it's not possible to use the scope as a video display for watching TV
during working hours.

Instek GDS-2204. Maybe it has it, hidden somewhere. These things have so
many menu options nowadays that it takes a while to really find out
what's there. But TV? Ain't nothing interesting on there for me.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
Perhaps hire an artist have have them sketch the display?

Hmm, I might not even have to, my wife is pretty good at pencil
drawings. Now I'd just have to cajole that pulse noise into sitting
still for 10 minutes or so.

Tell her it's good training for catching moving artisitic subjects and
speed sketching. However, that will work only long enough for her to
realize she's been tricked. Methinks it would be easier and safer to
teach your jr engineer or tech to sketch.

Post by Joerg
There remains a wee problem though: I am a consultant and the engineers
I am talking to are anywhere from 25 miles to 6000 miles from here. We
do have a runway right in town and my office is next to it but I haven't
found the matching LearJet on EBay yet.

Telepresence and Waldo. There are major strides being made in robotic
remote manipulation and visulization. Just build a robotic clone of
yourself and install it at the customers. If the medical profession
can do surgery over the internet, you can easily run a remote spectrum
analyzer. Operate it from your overstuffed easy chair. Not only can
you do the pre-compliance qualification, but you can also intimidate
the customer into paying the bill.
<http://en.wikipedia.org/wiki/Waldo_%28short_story%29>
<http://en.wikipedia.org/wiki/Telepresence>
If that's too much, get a GPIB to ethernet adapter, plug it into the
customers network, and run the spectrum analyzer yourself via the
internet.

Seriously, that's one thing I am thinking about. Controlling a DSO from
here and remotely show a young grad at the other end how to measure a
magnetics spike. Technically it's possible, if it weren't for that
stupid mscomm.ocx block. But I'll get around that when I've got time to
study VBA some more. Now I need to obtain an overstuffed easy chair.

[Jeff Liebermann]

On Thu, 20 Sep 2007 17:33:48 GMT, Joerg

Post by Joerg
Instek GDS-2204. Maybe it has it, hidden somewhere. These things have so
many menu options nowadays that it takes a while to really find out
what's there. But TV? Ain't nothing interesting on there for me.

No z-axis input on the data sheet:
<http://www.instek.com/GDS-2000.htm>
Nice scope, but useless for watching TV or emulating an x-y plotter.
It has all the video triggering modes, but no way to watch the
picture. Also, 320x234 isn't going to look too wonderful.

Post by Joerg

Post by Jeff Liebermann
If that's too much, get a GPIB to ethernet adapter, plug it into the
customers network, and run the spectrum analyzer yourself via the
internet.

Seriously, that's one thing I am thinking about. Controlling a DSO from
here and remotely show a young grad at the other end how to measure a
magnetics spike. Technically it's possible, if it weren't for that
stupid mscomm.ocx block. But I'll get around that when I've got time to
study VBA some more. Now I need to obtain an overstuffed easy chair.

I wish to retain my sanity and will therefore deny any knowledge of
Visual Basic or other forms of programming.

The scope does seem to be remote controllable via RS-232, USB, or
optional GPIB. I suggest you look into an ethernet to RS-232
converter, such as a Lantronix xport
<http://www.lantronix.com/device-networking/embedded-device-servers/xport.html>
<http://www.lantronix.com/device-networking/embedded-device-servers/xport-direct.html>
and experiment with remote control. Using RS-232 isn't going to be
the fastest solution, but it's the cheapest and probably easiest. I've
had good luck with most test equipment control programs running them
through the Lantronix serial port emulator:
<http://www.lantronix.com/device-networking/utilities-tools/com-port-redirector.html>

Overstuffed easy chairs can be easily found wherever the dot.com
failures sold their used furniture. Mine was confiscated from a
dot.com manager, in lieu of back rent. I consider it to be an
essential part of my office as an aid to daydreaming, loafing, and
power naps.

[Joerg]

Post by Jeff Liebermann
On Thu, 20 Sep 2007 17:33:48 GMT, Joerg

Post by Joerg
Instek GDS-2204. Maybe it has it, hidden somewhere. These things have so
many menu options nowadays that it takes a while to really find out
what's there. But TV? Ain't nothing interesting on there for me.

<http://www.instek.com/GDS-2000.htm>
Nice scope, but useless for watching TV or emulating an x-y plotter.
It has all the video triggering modes, but no way to watch the
picture. Also, 320x234 isn't going to look too wonderful.

Yeah, the screen resolution is nothing to write home about. However,
it's a rather bright screen which is nice for outdoor measurements and
you can also use a hi-res display mode on a connected laptop. AFAICT
then it pretty much depends on whatever the laptop can render. This .NET
based software is in a pretty elementary stage right now (beta) but does
the job.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
If that's too much, get a GPIB to ethernet adapter, plug it into the
customers network, and run the spectrum analyzer yourself via the
internet.

Seriously, that's one thing I am thinking about. Controlling a DSO from
here and remotely show a young grad at the other end how to measure a
magnetics spike. Technically it's possible, if it weren't for that
stupid mscomm.ocx block. But I'll get around that when I've got time to
study VBA some more. Now I need to obtain an overstuffed easy chair.

I wish to retain my sanity and will therefore deny any knowledge of
Visual Basic or other forms of programming.

Not that I like it much but let's face it, nearly all client's PCs will
have MS-Office on there. No problem to ask their IT guys to install
another license on a lab PC should it lack Excel. But to install a
home-made *.exe is a whole 'nother matter in large companies. They often
do not like to do that.

Post by Jeff Liebermann
The scope does seem to be remote controllable via RS-232, USB, or
optional GPIB. I suggest you look into an ethernet to RS-232
converter, such as a Lantronix xport
<http://www.lantronix.com/device-networking/embedded-device-servers/xport.html>
<http://www.lantronix.com/device-networking/embedded-device-servers/xport-direct.html>
and experiment with remote control. Using RS-232 isn't going to be
the fastest solution, but it's the cheapest and probably easiest. I've
had good luck with most test equipment control programs running them
<http://www.lantronix.com/device-networking/utilities-tools/com-port-redirector.html>

That would be the next step. First I want to be able to have a near-live
connection into Excel. The virtual COM port in there runs at full blast.

Post by Jeff Liebermann
Overstuffed easy chairs can be easily found wherever the dot.com
failures sold their used furniture. Mine was confiscated from a
dot.com manager, in lieu of back rent. I consider it to be an
essential part of my office as an aid to daydreaming, loafing, and
power naps.

And then the back pain sets in :-(

[Rich Grise]

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Connect it to the Z axis input (trace inhibit) of your DSO.

I am afraid it doesn't have that function. Unless it's thoroughly hidden
somewhere.

Sigh. What manner of DSO is this? Without an analog Z axis input,
it's not possible to use the scope as a video display for watching TV
during working hours.

If you have two, you can sync one to the vertical and the other to
the horizontal, the video to the vertical of each, and see a top
view on one and a side view on the other. Then, just mentallly
interpolate to derive the picture. ;-)

I have a pretty kewl scope with Z axis - all I'd need to watch TV
in my office/lab is some kind of vertical sweep (I'd use the horizontal
for horizontal ;-) ), a TV tuner, and a video amp. I might as well
go to the pawn shop and get a 5" portable for $10. ;-)

Cheers!
Rich

[Jeff Liebermann]

Post by Rich Grise
If you have two, you can sync one to the vertical and the other to
the horizontal, the video to the vertical of each, and see a top
view on one and a side view on the other. Then, just mentallly
interpolate to derive the picture. ;-)

Kinda reminds me of the rotating color disk TV standard proposed by
CBS in about 1947. It works, but who would want to use it?

Post by Rich Grise
I have a pretty kewl scope with Z axis - all I'd need to watch TV
in my office/lab is some kind of vertical sweep (I'd use the horizontal
for horizontal ;-) ), a TV tuner, and a video amp. I might as well
go to the pawn shop and get a 5" portable for $10. ;-)

It's not quite that easy. There are plenty of articles on the
internet for converting a television into a really awful oscilloscope,
but not the other way. I first did it in college (late 1960's) using
and RTL, DTL, and DCL sync seperator. It was all part of Learn By
Destroying(tm).

I found very few articles on the topic with Google. Looks it would
make a good student project.
<http://www.electronixandmore.com/project/14.html>
<http://www.earlytelevision.org/neitz.html>
<http://www.intio.or.jp/jf10zl/tv.htm>

[Joerg]

Post by Jeff Liebermann

Post by Rich Grise
If you have two, you can sync one to the vertical and the other to
the horizontal, the video to the vertical of each, and see a top
view on one and a side view on the other. Then, just mentallly
interpolate to derive the picture. ;-)

Kinda reminds me of the rotating color disk TV standard proposed by
CBS in about 1947. It works, but who would want to use it?

Would have created a whole new profit center in industry, the TV lube
and tune.

Post by Jeff Liebermann

Post by Rich Grise
I have a pretty kewl scope with Z axis - all I'd need to watch TV
in my office/lab is some kind of vertical sweep (I'd use the horizontal
for horizontal ;-) ), a TV tuner, and a video amp. I might as well
go to the pawn shop and get a 5" portable for $10. ;-)

It's not quite that easy. There are plenty of articles on the
internet for converting a television into a really awful oscilloscope,
but not the other way. I first did it in college (late 1960's) using
and RTL, DTL, and DCL sync seperator. It was all part of Learn By
Destroying(tm).
I found very few articles on the topic with Google. Looks it would
make a good student project.
<http://www.electronixandmore.com/project/14.html>
<http://www.earlytelevision.org/neitz.html>
<http://www.intio.or.jp/jf10zl/tv.htm>

It was done a lot in ham radio. Many folks will remember slow scan
television. If you were remotely related to the Rockefellers you'd
obtain a surplus scope with a slow decay tube. If you weren't, then you
got said tube at a flea market and built a crude scope. Around that the
sweep generator and sync was built, plus the signal path filtering and
demodulator.

The high voltage generation was a bit of a challenge with 1970's parts.
Many a fine circuit came to grief in them days. The worst case was a guy
who managed to zap a HV jolt onto the +5V rail in his VME-style Eurocard
rack which contained all kinds of other circuits as well. It toasted
literally every single IC in there. The only thing that was still
working was the little lamp inside the power switch.

[Jeff Liebermann]

On Fri, 21 Sep 2007 23:58:43 GMT, Joerg

Post by Joerg

Post by Jeff Liebermann
Kinda reminds me of the rotating color disk TV standard proposed by
CBS in about 1947. It works, but who would want to use it?

Would have created a whole new profit center in industry, the TV lube
and tune.

What was amazing was that it actually did work. RCA had a hell of
time demonstrating a functional CRT system, mostly because they were
really pushing the state of the art. The only reason the CBS system
was seriously considered by the FCC was that none of the other
proposed systems were functional at the time. I don't recall the
exact dimensions, but a 19" color TV would have required something
like a 15ft diameter color wheel.

Post by Joerg
It was done a lot in ham radio. Many folks will remember slow scan
television. If you were remotely related to the Rockefellers you'd
obtain a surplus scope with a slow decay tube. If you weren't, then you
got said tube at a flea market and built a crude scope. Around that the
sweep generator and sync was built, plus the signal path filtering and
demodulator.

Please. Just thinking about it gives me nightmares from projects long
dead and buried. I was involved in one of the numerous abortive
attempts to develop a sellable picture phone. The basic problem was
to design a system that could shovel video over a really awful phone
line, with incredibly bad group delay, and without adaptive equalizers
or echo cancellers, and still have enough bandwidth to sneak voice in
between the frames. It was one of the few projects where the
engineers gave up before the customer fired us. At this stage, my
design abilities were limited to stealing test equipment and raiding
the stockroom for parts, for the engineers. Incidentally, this was
just after the Carterphone decision (1968?) which required that we had
to acoustically couple the video to the phone handset. Banging the
carbon microphone to loosen the packet granules was the first step in
the operating instructions.

Post by Joerg
The high voltage generation was a bit of a challenge with 1970's parts.

At one point, I tried to replace a TV flyback with an automobile
ignition coil. It didn't work, but the sparks and smoke were
certainly impressive.

In the early 1960's (High Skoll), our radio club built a SSTV system
using most of a donated commercial fax machine. The original used a
huge sheet of photosensitive paper and a flash tube. We modified it
to use a drafting pen and solenoid. It didn't do photos very well,
but the various weather maps and over the air news broadcasts were
quite readable. The only real problem is that the monster had a
mechanical drum speed adjustment with no synchronization. Skew and
drift were a constant problem. I kinda miss the days when I had no
idea what I was doing and never let that stop me.

Post by Joerg
Many a fine circuit came to grief in them days. The worst case was a guy
who managed to zap a HV jolt onto the +5V rail in his VME-style Eurocard
rack which contained all kinds of other circuits as well. It toasted
literally every single IC in there. The only thing that was still
working was the little lamp inside the power switch.

Nice. I'll spare you my damage report of equipment destroyed. (Note
that my domain name is Learn By Destroying). My all time high was a
4Kw NMR (nuke magnetic resonance) power amplifier, which used 8ea VMOS
power xsistors. These were something like $200/ea in 1979. Although
the devices were claimed to be unconditionally stable, I managed to
find a source and load combination which sent the amplifier into
oscillation. That blew all 8 power xsistors, sending ceramic shrapnel
bouncing around the rack (with my head still inside the rack).

High voltage is always fun for destroying small signal devices.
However, for really impressive fireworks and destruction, high current
is much better. Nothing like watching a steel crow bar turn bright
red and vaporize after being dropped on the -48VDC battery terminals.
If a fuse blew, the fuse cabinet was usually replaced along with the
fuse.

[Joerg]

Post by Jeff Liebermann
On Fri, 21 Sep 2007 23:58:43 GMT, Joerg

Post by Joerg

Post by Jeff Liebermann
Kinda reminds me of the rotating color disk TV standard proposed by
CBS in about 1947. It works, but who would want to use it?

Would have created a whole new profit center in industry, the TV lube
and tune.

What was amazing was that it actually did work. RCA had a hell of
time demonstrating a functional CRT system, mostly because they were
really pushing the state of the art. The only reason the CBS system
was seriously considered by the FCC was that none of the other
proposed systems were functional at the time. I don't recall the
exact dimensions, but a 19" color TV would have required something
like a 15ft diameter color wheel.

So you'd need a new house along with that TV. Oh man. What would have
happened if that wheel went out of balance?

Post by Jeff Liebermann

Post by Joerg
It was done a lot in ham radio. Many folks will remember slow scan
television. If you were remotely related to the Rockefellers you'd
obtain a surplus scope with a slow decay tube. If you weren't, then you
got said tube at a flea market and built a crude scope. Around that the
sweep generator and sync was built, plus the signal path filtering and
demodulator.

Please. Just thinking about it gives me nightmares from projects long
dead and buried. I was involved in one of the numerous abortive
attempts to develop a sellable picture phone. The basic problem was
to design a system that could shovel video over a really awful phone
line, with incredibly bad group delay, and without adaptive equalizers
or echo cancellers, and still have enough bandwidth to sneak voice in
between the frames. It was one of the few projects where the
engineers gave up before the customer fired us. At this stage, my
design abilities were limited to stealing test equipment and raiding
the stockroom for parts, for the engineers. Incidentally, this was
just after the Carterphone decision (1968?) which required that we had
to acoustically couple the video to the phone handset. Banging the
carbon microphone to loosen the packet granules was the first step in
the operating instructions.

Post by Joerg
The high voltage generation was a bit of a challenge with 1970's parts.

At one point, I tried to replace a TV flyback with an automobile
ignition coil. It didn't work, but the sparks and smoke were
certainly impressive.
In the early 1960's (High Skoll), our radio club built a SSTV system
using most of a donated commercial fax machine. The original used a
huge sheet of photosensitive paper and a flash tube. We modified it
to use a drafting pen and solenoid. It didn't do photos very well,
but the various weather maps and over the air news broadcasts were
quite readable. The only real problem is that the monster had a
mechanical drum speed adjustment with no synchronization. Skew and
drift were a constant problem. I kinda miss the days when I had no
idea what I was doing and never let that stop me.

Ah, a "stench fax"? A stylus hovered over sensitive paper and arced away
stuff to write. After a few pages the air in the room became unbearable.
Who knows what was in that air.

Post by Jeff Liebermann

Post by Joerg
Many a fine circuit came to grief in them days. The worst case was a guy
who managed to zap a HV jolt onto the +5V rail in his VME-style Eurocard
rack which contained all kinds of other circuits as well. It toasted
literally every single IC in there. The only thing that was still
working was the little lamp inside the power switch.

Nice. I'll spare you my damage report of equipment destroyed. (Note
that my domain name is Learn By Destroying). My all time high was a
4Kw NMR (nuke magnetic resonance) power amplifier, which used 8ea VMOS
power xsistors. These were something like $200/ea in 1979. Although
the devices were claimed to be unconditionally stable, I managed to
find a source and load combination which sent the amplifier into
oscillation. That blew all 8 power xsistors, sending ceramic shrapnel
bouncing around the rack (with my head still inside the rack).

Hopefully that wasn't beryllium oxyde ...

Post by Jeff Liebermann
High voltage is always fun for destroying small signal devices.
However, for really impressive fireworks and destruction, high current
is much better. Nothing like watching a steel crow bar turn bright
red and vaporize after being dropped on the -48VDC battery terminals.
If a fuse blew, the fuse cabinet was usually replaced along with the
fuse.

But HV created that impressive bang when something went.

[Jeff Liebermann]

Post by Joerg
So you'd need a new house along with that TV. Oh man. What would have
happened if that wheel went out of balance?

Not much. Most of the original versions were intended for the 9"
round displays of the late 1940's. The wheel was located inside the
cabinet for safety reasons. There were "scanning adapters" that
converted B&W sets into color TV, which were external. The disk was
fairly light weight, which served to reduce damage, injuries, and
fatalities. The only big external wheel was the monster that RCA
dragged into the FCC hearing room to demonstrate how badly the CBS
system scaled.

Despite the obvious disadvantages of the CBS system, it has several
major advantages.
1. It was cheaper than any of the others.
2. It was using a known technology (Nipov scanner).
3. The pictures were absolutely gorgeous compared to the RCA "dot
sequential" system.
<http://novia.net/~ereitan/CBS_Chronology_rev_h_edit.htm>
(Who needs HDTV anyway?)
4. It can be used to "convert" a B&W TV into a color TV.
5. It can be resurrected from the dead today by using 2-5msec
persistence LCD screens.

CBS eventually gave up on color wheels and switched back to their
earlier "field sequential" system, but piggy backed on the RCA/NTSC
system in order to insure B&W set compatibility. Field sequential
also produced color better than RCA's dot sequential:
<http://www.earlytelevision.org/chromacoder.html>
Note the "scanning adapter".
<http://www.earlytelevision.org/cbs_color_system.html>

You might find the chronology of the CBS system and the FCC hearings
of interest. Nobody wanted the CBS system, but everything else was a
kludge:
<http://www.earlytelevision.org/color_tv_cooper.html>

Post by Joerg
Ah, a "stench fax"? A stylus hovered over sensitive paper and arced away
stuff to write. After a few pages the air in the room became unbearable.
Who knows what was in that air.

Nope, although I did own WXFAX contrivance that used spark gap
imaging. If you do it right, you can set fire to the paper. It
worked best with a small spark gap and Thermofax paper. I don't
recall any smell other than the usual toxic ozone stench and vaporized
heavy metal smog. Somewhat earlier, I ran the college print shop. We
used a Gestetner stencil cutter for the mimeograph printer, which used
a spark gap to blast holes in the stencil. I'm not sure what they did
different, but there was very little smell, and no smoke.

The contrivance I helped resurrect was basically a rotating pen
plotter. I took a Koh-i-noor drafting pen, feed it with a reservoir
full of India Ink, and uses a solenoid to move the pen up and down.
The major challenge was to not spray ink all over the place, which was
partly solved by using the smallest 00 or 000 pen available.
Unfortunately, it would usually clog if left standing for more than a
few minutes. I think I was 16 years old at the time, so please don't
expect much in the way of engineering elegance.

Post by Joerg
Hopefully that wasn't beryllium oxyde ...

It was. Lots of ceramic fragments flying around. Fortunately, the
power amp wasn't running long enough to get them hot. Still, I had a
few small cuts and piece of ceramic imbedded in my face. The
attendant crowd was debating whether to drag me to the local emergency
room, or to complete my execution in retaliation for destroying the
last remaining VMOS transistors. While they debated, I picked out the
pieces of ceramic with a tweezer, and fell asleep under my desk. Since
the employee handbook does not cover murdering sleeping employees, I
survived.

Post by Joerg
But HV created that impressive bang when something went.

Bah. Real devastation can only be appreciated by the overwhelming
application of power, not voltage. Hot slag spewing from the shorting
bar. Melted copper and immolated components. Burning components,
circuit boards, and insulation. While admittedly, high voltage can
destroy a greater variety of devices and components, truly massive and
permanent devastation requires lots of watts.

Remember: Learn by Destroying, which means if you haven't destroyed
it, you don't understand it.

[Jeff Liebermann]

Post by Joerg
So you'd need a new house along with that TV. Oh man. What would have
happened if that wheel went out of balance?

More... Photo of a CBS converter:
<http://www.earlytelevision.org/cbs_color_converter.html>

The CBS system wasn't the only color wheel. In 1955, we were blessed
with the Col-R-Tel spinning wheel system:
<http://www.hawestv.com/mtv_color/colrtel_block.htm>
and others:
<http://www.hawestv.com/mtv_color/colrtel_compet.htm>

Incidentally, the CBS wheel spun at 1440 rpm, while the Col-R-Tel
system ran at 600 rpm.

[RST Engineering (jw)]

But your contract Cessna 182 is less than 20 miles north.

{;-)

Jim
--
"If you think you can, or think you can't, you're right."
--Henry Ford




"Joerg" <***@removethispacbell.net> wrote in message
news:n9fIi.4716

There remains a wee problem though: I am a consultant and the engineers I
am talking to are anywhere from 25 miles to 6000 miles from here. We do
have a runway right in town and my office is next to it but I haven't
found the matching LearJet on EBay yet.
--
Regards, Joerg
http://www.analogconsultants.com

[Joerg]

Post by RST Engineering (jw)
But your contract Cessna 182 is less than 20 miles north.
{;-)

Ah, the Skylane. Nice aircraft. Is it the retractable? This would be the
perfect mode of transportation to one of my clients because they are
less than 100 miles away (more than 130 miles by car) and I could walk
over there from the FBO in minutes.

Unfortunately my wife is not too fond of flying. Before we married she
kindly asked me whether it would be remotely possible to give up
parachuting.

Also, I am not too sure about the future of this airport here. A bit too
many fatal accidents, too many dare-devil pilots where people get angry
and it's only a matter of time until an accident like the one in
Roseville happens. Seems to be financially strapped as well. They asked
us to remove our trees for an obstruction light many years ago because
the FAA demanded one up here. Trees gone, light on our hill was never
installed and I don't think the FAA let's them disregard their
requirements forever. They did install three lights on a hill for the 31
approach if you ever head here at night.

[Paul Mathews]

Post by Joerg

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Well, there are spectrum analyzers that have the tradition mess of BNC
connectors on the back, which usually include something to drive a pen
plotter. They're usually labelled X, Y, and pen lift. You can
probably do something useful with that. XY pen plotters can still be
found, or just use your DSO.

The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

You're lazy, but such laziness has been the inspiration behind some of
my best ideas. Don't let it bother you (much).
How about a compromise? Instead of a USB stick, one of the ever
growing variety of memory cards that are being used in digital cameras
will probably suffice. Build a cardboard or foam board hood and mount
the camera at the correct location. Make it fairly long (about 0.8
meters) so that you don't have a depth of field problem, where the
focus is different in the display center and at the edges. Pre-focus
and set the zoom. Paint the hood black inside. When the display has
something that's worth capturing, push the shutter button. Clean up
the picture with Photoshop or Irfanview.
If dealing with the memory card is too much for you, run a USB cable
to the camera, and capture the image directly on your PC. The only
problem with this approach is that the "video" mode on most cheap
digital cameras is 320x240 or 640x480 at best. That may not be enough
for a detailed photo. However, I've seen spectrum analyzer photos on
FCC type certification documents that look like they were frame
grabbed from a video camera, so this method is probably suitable for
pre-certification.

That's how I do it now. Would be nice if I didn't have to ;-)
But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment". Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."
--
Regards, Joerg
http://www.analogconsultants.com- Hide quoted text -
- Show quoted text -- Hide quoted text -
- Show quoted text -

My clients typically pay about $1000/day or more for EMI test lab
time. I've come into situations where they've already spend $50K or
more on repeated trips to the labs, so they are sometimes ready to
discuss spending $20K on some pre-compliance gear. The engineers
ALWAYS need training, although I agree that it would be a little
easier if the equipment was easier to use, and we can hope that we
won't have to wait much longer. In the meantime, anyone can learn a
lot by sniffing around with near field probes, particularly B-field
probes, and the controls of most portable spectrum analyzers are
really pretty simple: Start Freq, Stop Freq, BW, Sweep Time, Level/
Attenuation are the main ones to know about. They need to understand
how Sweep Time needs to be long enough to capture sufficient energy to
measure at each frequency. A good broadband preamp is a necessity, but
the Ramsey SA7 is available for $20 in a kit or about $70 assembled.
You can pick up an older Anritsu, HP, Advantest, Marconi, Tektronix or
other brand portable spectrum analyzer for under $2K with GPIB. It's
not too difficult to get any of these to respond to remote commands.
If anyone wants to use it as a starting point, I'll share my VB
sourcecode for an app that controls the SA, uploads and downloads
traces, overlays EMI compliance limit lines, compares traces before
and after mods and setup changes, sets up the SA in various default
configurations, etc, etc. I have HP959x and Anritsu MS420 versions. No
support beyond commented sourcecode.
Here's some articles that teach about building your own near field
probes and LISN and how to use them:

http://www.cherryclough.com/Pages/Publications%20and%20downloads.htm

EMI sniffer probes:

http://www.bcarsten.com/?page=probes buy from Bruce or use his design
(see link on page)

http://www.bcarsten.com/?page=appnote

http://emcesd.com/ (see middle of page and get ready to be
overwhelmed)

The link above gets you to more info than you'll ever need to build
and use your own pre-compliance probes.

Wideband Preamplifiers:

Search ebay for HP 8447A/B/C/D and pay a few hundred $ or
http://www.amazon.com/Ramsey-PR2-Broadband-Preamplifier-Assembled/dp/B0002NRKMG
this looks interesting, too:
http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=PP1

other good sites:

http://www.planetanalog.com/showArticle.jhtml?articleID=15201507
(first of a series of 7 excellent articles by Sanjaya Maniktala)

http://www.planetanalog.com/showArticle.jhtml?articleID=16101396
(last of the 7 above)

http://www.compliance-club.com/index.asp

http://www.steward.com/pdfs/emi/technical/EMI%20Testing%20Fund.pdf

http://www.sigcon.com/publications.htm

Paul Mathews

[John Larkin]

Post by Paul Mathews

Post by Joerg

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Well, there are spectrum analyzers that have the tradition mess of BNC
connectors on the back, which usually include something to drive a pen
plotter. They're usually labelled X, Y, and pen lift. You can
probably do something useful with that. XY pen plotters can still be
found, or just use your DSO.

The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

You're lazy, but such laziness has been the inspiration behind some of
my best ideas. Don't let it bother you (much).
How about a compromise? Instead of a USB stick, one of the ever
growing variety of memory cards that are being used in digital cameras
will probably suffice. Build a cardboard or foam board hood and mount
the camera at the correct location. Make it fairly long (about 0.8
meters) so that you don't have a depth of field problem, where the
focus is different in the display center and at the edges. Pre-focus
and set the zoom. Paint the hood black inside. When the display has
something that's worth capturing, push the shutter button. Clean up
the picture with Photoshop or Irfanview.
If dealing with the memory card is too much for you, run a USB cable
to the camera, and capture the image directly on your PC. The only
problem with this approach is that the "video" mode on most cheap
digital cameras is 320x240 or 640x480 at best. That may not be enough
for a detailed photo. However, I've seen spectrum analyzer photos on
FCC type certification documents that look like they were frame
grabbed from a video camera, so this method is probably suitable for
pre-certification.

That's how I do it now. Would be nice if I didn't have to ;-)
But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment". Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."
--
Regards, Joerg
http://www.analogconsultants.com- Hide quoted text -
- Show quoted text -- Hide quoted text -
- Show quoted text -

My clients typically pay about $1000/day or more for EMI test lab
time. I've come into situations where they've already spend $50K or
more on repeated trips to the labs, so they are sometimes ready to
discuss spending $20K on some pre-compliance gear.

If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

John

[Paul Mathews]

On Sep 20, 8:59 am, John Larkin

Post by John Larkin

Post by Paul Mathews

Post by Joerg

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Well, there are spectrum analyzers that have the tradition mess of BNC
connectors on the back, which usually include something to drive a pen
plotter. They're usually labelled X, Y, and pen lift. You can
probably do something useful with that. XY pen plotters can still be
found, or just use your DSO.

The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

You're lazy, but such laziness has been the inspiration behind some of
my best ideas. Don't let it bother you (much).
How about a compromise? Instead of a USB stick, one of the ever
growing variety of memory cards that are being used in digital cameras
will probably suffice. Build a cardboard or foam board hood and mount
the camera at the correct location. Make it fairly long (about 0.8
meters) so that you don't have a depth of field problem, where the
focus is different in the display center and at the edges. Pre-focus
and set the zoom. Paint the hood black inside. When the display has
something that's worth capturing, push the shutter button. Clean up
the picture with Photoshop or Irfanview.
If dealing with the memory card is too much for you, run a USB cable
to the camera, and capture the image directly on your PC. The only
problem with this approach is that the "video" mode on most cheap
digital cameras is 320x240 or 640x480 at best. That may not be enough
for a detailed photo. However, I've seen spectrum analyzer photos on
FCC type certification documents that look like they were frame
grabbed from a video camera, so this method is probably suitable for
pre-certification.

That's how I do it now. Would be nice if I didn't have to ;-)
But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment". Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."
--
Regards, Joerg
http://www.analogconsultants.com-Hide quoted text -
- Show quoted text -- Hide quoted text -
- Show quoted text -

My clients typically pay about $1000/day or more for EMI test lab
time. I've come into situations where they've already spend $50K or
more on repeated trips to the labs, so they are sometimes ready to
discuss spending $20K on some pre-compliance gear.

If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.
John- Hide quoted text -
- Show quoted text -

I agree, although many small companies have trouble coming up with
capital expense money, particularly after they have blown big bucks on
failed compliance efforts. Then, they bring in the expensive
consultant, and it can be even harder to get the money. Most companies
I've gotten into are set up in a way that encourages wasteful internal
spending over judicious external 'off-budget' spending.
Paul Mathews

[Joerg]

Post by Paul Mathews
On Sep 20, 8:59 am, John Larkin

Post by John Larkin

Post by Paul Mathews

Post by Joerg

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann

Post by Joerg
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

Check if your SA has a plotter output. There are PC based HPGL
<http://www.fplot.com>
<http://www.printcapture.com>

If you can get it from that dreaded HPIB connector to something more
normal. There are ways but when on the road that gets old.

Well, there are spectrum analyzers that have the tradition mess of BNC
connectors on the back, which usually include something to drive a pen
plotter. They're usually labelled X, Y, and pen lift. You can
probably do something useful with that. XY pen plotters can still be
found, or just use your DSO.

The pen lift thing would present a wee problem with the DSO. Other than
that it could do it since mine and probably most others are capable of
X-Y plots.

Post by Jeff Liebermann

Post by Joerg

Post by Jeff Liebermann
I've used a digital camera for grabbing scope traces. My black
cardboard "scope camera" is ugly but functional.
One device just wouldn't cooperate. I found where the X-Y signals to
the scope section could be found and attached scope probes from a DSO
(digital storage oscillosope) to grab the trace. Many scopes that
have an external display or perhaps "HP storage normalizer" have
external X-Y signals available on a connector.

Ok, call me lazy but I'd rather have a button that says "Store trace on
USB stick".

You're lazy, but such laziness has been the inspiration behind some of
my best ideas. Don't let it bother you (much).
How about a compromise? Instead of a USB stick, one of the ever
growing variety of memory cards that are being used in digital cameras
will probably suffice. Build a cardboard or foam board hood and mount
the camera at the correct location. Make it fairly long (about 0.8
meters) so that you don't have a depth of field problem, where the
focus is different in the display center and at the edges. Pre-focus
and set the zoom. Paint the hood black inside. When the display has
something that's worth capturing, push the shutter button. Clean up
the picture with Photoshop or Irfanview.
If dealing with the memory card is too much for you, run a USB cable
to the camera, and capture the image directly on your PC. The only
problem with this approach is that the "video" mode on most cheap
digital cameras is 320x240 or 640x480 at best. That may not be enough
for a detailed photo. However, I've seen spectrum analyzer photos on
FCC type certification documents that look like they were frame
grabbed from a video camera, so this method is probably suitable for
pre-certification.

That's how I do it now. Would be nice if I didn't have to ;-)
But it's not so much me, it's for clients. Most young engineers are not
very familiar with spectrum analysis, much less with vintage equipment.
It would be great if I could tell them "Press this, then that and later
the other button and shoot it over via email attachment". Then I could
look at the plot and tell them "Place 220uH between D17 and C45, then do
the spectrum again."
--
Regards, Joerg
http://www.analogconsultants.com-Hide quoted text -
- Show quoted text -- Hide quoted text -
- Show quoted text -

My clients typically pay about $1000/day or more for EMI test lab
time. I've come into situations where they've already spend $50K or
more on repeated trips to the labs, so they are sometimes ready to
discuss spending $20K on some pre-compliance gear.

If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.
John- Hide quoted text -
- Show quoted text -

I agree, although many small companies have trouble coming up with
capital expense money, particularly after they have blown big bucks on
failed compliance efforts. Then, they bring in the expensive
consultant, and it can be even harder to get the money. Most companies
I've gotten into are set up in a way that encourages wasteful internal
spending over judicious external 'off-budget' spending.

That's the point. Start-ups must be very frugal but have more freedom.
They can and do go out there on EBay and just buy what's needed. Usually
I give them a laundry list of gear that would work for the situation
just like you did in your previous post and a few days later they report
that they just nailed a bid.

Larger corps, oh no. If it ain't budgeted it usually ain't going to
happen. CapEx, payroll, inventory and WIP are closely watched numbers.
They aren't supposed to rise, ever, unless matched by an increase in
gross margin or at least in gross sales. I know, because I once ran a
division. Running expenses such as for EMC lab time or for consultants
are much easier to be granted, usually. Back in them days I was the
grantor ;-)

BTW, if your code is Excel VBA based and can run via the API and without
mscomm.ocx I'd be very interested. To run a scope here, but mostly as
study material because I have to learn this stuff.

[John Devereux]

John Larkin <***@highNOTlandTHIStechnologyPART.com> writes:

[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

[Joerg]

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

Sometimes I am thinking about buying half a dozen Tek 2465. Just in case
they become extinct on EBay and I encounter another client that has no
decent analog scope.

[John Larkin]

On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

John

[John Devereux]

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).

Anyone used a higher-end modern digital scope?

<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

[Joerg]

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have, at a client. Let's put it that way: I was not too enthused.
There are many things you just can't do with a digital scope, no matter
how many bells, whistle and persistence features they add in.

At the end of the day my recommendation to clients whose labs are
exclusively TDS and DPO usually is: Go on EBay and bid on a Tektronix 2465.

[Terry Given]

Post by Joerg

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have, at a client. Let's put it that way: I was not too enthused.
There are many things you just can't do with a digital scope, no matter
how many bells, whistle and persistence features they add in.
At the end of the day my recommendation to clients whose labs are
exclusively TDS and DPO usually is: Go on EBay and bid on a Tektronix 2465.

DPO is a real PITA. You *cant* turn it off, but have to go to the
correct menu and press the "clear persistence" button to see a single
trace. Grrr....

the really annoying thing is that Tek *could* have added a "no DPO"
setting, but chose not to.

Cheers
Terry

[Joerg]

Post by Terry Given

Post by Joerg

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have, at a client. Let's put it that way: I was not too enthused.
There are many things you just can't do with a digital scope, no
matter how many bells, whistle and persistence features they add in.
At the end of the day my recommendation to clients whose labs are
exclusively TDS and DPO usually is: Go on EBay and bid on a Tektronix 2465.

DPO is a real PITA. You *cant* turn it off, but have to go to the
correct menu and press the "clear persistence" button to see a single
trace. Grrr....
the really annoying thing is that Tek *could* have added a "no DPO"
setting, but chose not to.

I just hope they haven't replaced all of their old-timers with fresh
grads without any field experience. IMHO a scope designer should have
10+ years of hardcore analog design work under the belt.

[Phil Hobbs]

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have to
sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll try
it out with my 11801C and see if it's telling the truth.

Cheers,

Phil Hobbs

[John Devereux]

Post by Phil Hobbs

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have
to sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll
try it out with my 11801C and see if it's telling the truth.

Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.

[Phil Hobbs]

Post by John Devereux

Post by Phil Hobbs

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have
to sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll
try it out with my 11801C and see if it's telling the truth.

Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.

That's usually called 'high resolution' mode, and all my digital Teks
have it. Yours doesn't? Weird.

(Of course I hate that mode like poison myself--I try to sit in min-max
mode, so I can see what's really being digitized.)

For the stuff I do, I'd be much happier with my 11801C, if only my YAG
laser's rep rate were more than 20 Hz--which takes *forever* to get a
decent trace, especially since its pulse-to-pulse energy varies almost
2:1 p-p.

Cheers,

Phil Hobbs

Cheers,

Phil Hobbs

[John Devereux]

Post by Phil Hobbs

Post by John Devereux

Post by Phil Hobbs

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have
to sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll
try it out with my 11801C and see if it's telling the truth.

Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.

That's usually called 'high resolution' mode, and all my digital Teks
have it. Yours doesn't? Weird.

I'm pretty sure it doesn't. You *can* average successive traces. This
is great for extracting a synchronous signal from noise, like residual
switching spikes from a SMPS.

Post by Phil Hobbs
(Of course I hate that mode like poison myself--I try to sit in
min-max mode, so I can see what's really being digitized.)

I think it would be very useful for low level analog work in the DC -
few MHz regime. Also useful would be a more variable bandwidth, which
could also be done with some simple DSP.

Post by Phil Hobbs
For the stuff I do, I'd be much happier with my 11801C, if only my YAG
laser's rep rate were more than 20 Hz--which takes *forever* to get a
decent trace, especially since its pulse-to-pulse energy varies almost
2:1 p-p.

[Paul Mathews]

Post by John Devereux

Post by Phil Hobbs

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have
to sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll
try it out with my 11801C and see if it's telling the truth.

Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.
--
John Devereux- Hide quoted text -
- Show quoted text -

What do you mean by 'averaging of its sample rate'? You DO have the
option of averaging successive traces (Acquisition Mode menu). Perhaps
you're referring to some kind of sampling dither? You can also reduce
vertical BW to reduce the noise (a little).
Paul Mathews

[John Larkin]

Post by Paul Mathews

Post by John Devereux

Post by Phil Hobbs

Post by John Devereux

Post by John Larkin
On Thu, 20 Sep 2007 18:23:16 +0100, John Devereux

Post by John Devereux
[...]

Post by John Larkin
If a decent spectrum analyzer costs $12K, and it may last for 10
years, that's 1200 a year. Less tax depreciation (or just expense it)
that's maybe $800, under $70 a month. That's not even coffee+pastry
money around here. It usually makes sense to buy good new test gear
and spend your time designing products.

Says the guy with 10 identical old scopes he bought off ebay :)

In that case, the older gear is just about as good as the new stuff,
at about 1% of the price. Besides, I like scopes!

Yeah, me too. (I have a couple of older Tek analog scopes, which I
bought *after* the more modern TDS3054).
Anyone used a higher-end modern digital scope?
<http://www.tek.com/products/oscilloscopes/dpo7000/>
<http://www.tek.com/products/oscilloscopes/dpo4000/index.html>

I have a 20 Gs/s Tek (7 GHz BW) that I use occasionally...but those
sorts of things just aren't as trustworthy as slower ones. They have
to sweep a lot of stuff under a huge DSP rug in order to make a nice
display. Of course the Agilent ones are smoother looking, but that
makes me more suspicious rather than less. One of these times I'll
try it out with my 11801C and see if it's telling the truth.

Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.
--
John Devereux- Hide quoted text -
- Show quoted text -

What do you mean by 'averaging of its sample rate'? You DO have the
option of averaging successive traces (Acquisition Mode menu). Perhaps
you're referring to some kind of sampling dither? You can also reduce
vertical BW to reduce the noise (a little).
Paul Mathews

It could, at lower sweep rates, sample fast and average clusters of
samples withing one sweep, to reduce noise and improve resolution.
Seems to me that something could be done to reduce aliasing, too.

Yesterday I was surprised to see a reverse ringing oscillation. It
started as a little wiggle and increased in amplitide, then abruptly
died.


||
|||
||||
|||||
||||||
----------|||||||------------
||||||
|||||
||||
|||
||

which was of course a flipped-in-time alias of a real, very high
frequency ring.

John

[John Devereux]

[...]

Post by John Larkin

Post by Paul Mathews

Post by John Devereux
Actually one of the things I dislike about my TDS3054 is that it does
*not* do this much. The trace can be a bit noisy. I see no reason not
to have an option to do averaging of its 5Gs/s sample rate, at the lower
sweep speeds.
--
John Devereux- Hide quoted text -
- Show quoted text -

What do you mean by 'averaging of its sample rate'? You DO have the
option of averaging successive traces (Acquisition Mode menu). Perhaps
you're referring to some kind of sampling dither? You can also reduce
vertical BW to reduce the noise (a little).
Paul Mathews

It could, at lower sweep rates, sample fast and average clusters of
samples withing one sweep, to reduce noise and improve resolution.
Seems to me that something could be done to reduce aliasing, too.

Yes, I was looking for precisely that.

Post by John Larkin
Yesterday I was surprised to see a reverse ringing oscillation. It
started as a little wiggle and increased in amplitide, then abruptly
died.
||
|||
||||
|||||
||||||
----------|||||||------------
||||||
|||||
||||
|||
||
which was of course a flipped-in-time alias of a real, very high
frequency ring.

:)

[Martin Griffith]

On Tue, 18 Sep 2007 13:53:54 -0700, in sci.electronics.design Joerg

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

This mob are now saying that their analysers are "USB2"
ready,(whatever that means). Includes free pc software
http://test1.contenttest.net/Spektrumanalysator_en.shtml.


Martin

[Joerg]

Post by Martin Griffith
On Tue, 18 Sep 2007 13:53:54 -0700, in sci.electronics.design Joerg

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

This mob are now saying that their analysers are "USB2"
ready,(whatever that means). Includes free pc software
http://test1.contenttest.net/Spektrumanalysator_en.shtml.

I know that company a little (and their chip designer). They do not have
any units suitable for the pre-compliance frequency range. Supposedly
coming but right now you'd have to buy two units and that becomes
expensive and cumbersome. And some clients need this capability now, not
next year or so.

[Chris Jones]

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

Is this any good? (I don't know the frequency range you need.)

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1076496

I have never seen one of those, I wonder if they're any good.

Chris

[Joerg]

Post by Chris Jones

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

Is this any good? (I don't know the frequency range you need.)
http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1076496
I have never seen one of those, I wonder if they're any good.

Don't know them either but from the spec sheet it doesn't look too
encouraging. -60dBc for two sigs 10dB below ref level could be a problem
out here, at least in the Bay Area. And you only get two BW settings
that don't seem to quite fit the quasi-peak checks one has to do for
EMC. But this is indeed an interesting approach, to have a PalmPilot in
there. However, it seems those little organizers are on the way out and
people got back to the old paper booklets. I never had a PalmPilot.

Nice to see that TTI is still around.

[Nico Coesel]

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

How about taking a picture with a digital camera?

Post by Joerg
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

Be patient! :-)

[Joerg]

Post by Nico Coesel

Post by Joerg
Hello Folks,
Clients often ask me what they'd need for pre-compliance. My default
answer is the Hameg 5510, around $2k, probably more after the $ decline.
Fits the bill, gets the job done, but it's hard to document your work.
The Atten AT5011 costs half that but I don't know it, haven't used it.
The problem with most of these: You can't easily dump the screen onto a
PC, let alone memory stick. My new DSO does that very nicely but that
company's analyzers are too expensive for this kind of job.

How about taking a picture with a digital camera?

That gets old. The main impediment is that you can't tell the digital
camera to correct for the antenna gain versus frequency before taking
the picture.

Post by Nico Coesel

Post by Joerg
Any other contenders? Ideally not a handheld but something that gets
plopped onto the benchs and plugs into mains. And no, I am not asking
again about USB analyzers as they don't seem to exist (I still think
somone could become rich if they made one).

Be patient! :-)

I've been patient for years. Still waiting ...