[Elecraft] KPA-100 with K2 ATU

[h***@juno.com]

Hi,

If I want to use the KPA-100 in the future, and still want to tune up my
antennas?

What ATU should I use, and if I can use the K2 ATU how do set up so that
the K2 will bring the 100W down to 3W, then put it back to 100W and
bypass the 20W tuner to transmit?? I would like to do this in the EC2 if
necessary.

DAniel

[Lyle Johnson]

Hello Daniel!

Post by h***@juno.com
If I want to use the KPA-100 in the future, and still want to tune up my
antennas?

Right now, you have to use an external ATU with the KPA100. When the KAt100
is available, then you can use it.

Post by h***@juno.com
What ATU should I use, and if I can use the K2 ATU how do set up so that
the K2 will bring the 100W down to 3W, then put it back to 100W and
bypass the 20W tuner to transmit??

Just turn the power control knob on the front panel from less than 1W to
100W. If ytou want to use a KAT2 inside the K2 and de-integrate the KPA100,
you can do this in the EC2. There are two web pages that show how to do
this.

Post by h***@juno.com
I would like to do this in the EC2 if necessary.

The KAT100 will be able to fit in the EC2, or the smaller EC15.

73,

Lyle KK7P

[Wayne Burdick]

Daniel,

If the K2 detects both tuners in the system, it will put the KAT2 into
through mode (CALP) and force it to antenna 1. The KAT100 will then be
the only tuner doing anything.

If the K2 detects a KPA100 in the system, the TUNE mode power level will
be 20 watts. If not, it will be 3 watts, and this will work with either
the KAT2 or the KAT100.

Like the KAT2, the KAT100 will have have two antenna jacks, controllable
with the ANT1/2 switch on the K2 front panel.

73,
Wayne
N6KR

Post by h***@juno.com
Hi,
If I want to use the KPA-100 in the future, and still want to tune up my
antennas?
What ATU should I use, and if I can use the K2 ATU how do set up so that
the K2 will bring the 100W down to 3W, then put it back to 100W and
bypass the 20W tuner to transmit?? I would like to do this in the EC2 if
necessary.
DAniel

[Tom Hammond NØSS]

Daniel

Post by h***@juno.com
If I want to use the KPA-100 in the future, and still want to tune up my
antennas?
What ATU should I use, and if I can use the K2 ATU how do set up so that
the K2 will bring the 100W down to 3W, then put it back to 100W and
bypass the 20W tuner to transmit?? I would like to do this in the EC2 if
necessary.

When the KPA100 is installed, the KAT2 is removed from the K2 case, so this
is not a problem, since it is not available.

If the KPA100 is installed remotely, AND the KAT2 remains installed within
the K2 case, the KAT2 is DISABLED and cannot by use while the KPA100 is
ATTACHED to the K2. In this case you will have to either use the KAT2-100
(or whatever nomenclature it will bear), or another external ATU.

If you wish to tune up under low power (e.g. with the KPA100 OUT of the
line), merely turn the power back to a level less than 11W and the KPA100
will drop out of the line. Also, when the KPA100 is IN-LINE, with you press
[TUNE] the output power from the KPA100 is set to 20W for ATU tuning purposes.

Hope this helps,

Tom Hammond N0SS

[Tim and Nancy Logan]

Now I'm getting confused again :-) With the KPA100 INSTALLED in the K2
and the KAT2 removed, my understanding is that it will tune and transmit
at QRP levels (under 5 watts) as well as the 100 watt level - both using
the same external tuner to be released in September. DO I have this
right? Thanks folks. Tim NZ7C

Post by Tom Hammond NØSS
If you wish to tune up under low power (e.g. with the KPA100 OUT of the
line), merely turn the power back to a level less than 11W and the KPA100
will drop out of the line. Also, when the KPA100 is IN-LINE, with you press
[TUNE] the output power from the KPA100 is set to 20W for ATU tuning purposes.
Hope this helps,

[Tom Hammond NØSS]

Post by Tim and Nancy Logan
Now I'm getting confused again :-) With the KPA100 INSTALLED in the K2
and the KAT2 removed, my understanding is that it will tune and transmit
at QRP levels (under 5 watts) as well as the 100 watt level - both using
the same external tuner to be released in September. DO I have this
right? Thanks folks. Tim NZ7C

Correct, sorry... I thought you were inquiring about using the KAT2 with
the KPA100 installed externally... no clue where I got THAT idea!

If your POWER control is set <11W, when you hit [TUNE] the K2 will transmit
at 3W output. If you have the [POWER] control set to 11W or more, it'll go
into TUNE mode at 20W.

And yes, the EXTERNAL tuner (KAT100) should tune without complaint at
EITHER power level.

73,

Tom N0SS

[Deinhardt, Toby]

Hallo,

Post by Wayne Burdick
If the K2 detects a KPA100 in the system, the TUNE mode power
level will
be 20 watts. If not, it will be 3 watts, and this will work
with either
the KAT2 or the KAT100.

I assume that if the QRO PA is not powered, this would mean
tuning at the 3 watt level with the QRP PA.

vy 73 de toby

[Lyle Johnson]

Hello Tim!

Post by Tim and Nancy Logan
Now I'm getting confused again :-) With the KPA100 INSTALLED in the K2
and the KAT2 removed, my understanding is that it will tune and transmit
at QRP levels (under 5 watts) as well as the 100 watt level...

With the KPA100 installed, the K2/100 has a TUNE power level of 20 watts.
It has an OPERATING power range from 1 to 100 watts. Of course, once you
have activated TUNE, you can turn the power control up or down to change it,
but the next time you activate TUINE it will again be at 20 watts.

If you remove power from the KPA100 power connector (the Anderson power pole
connector) and instead apply power to the ORIGINAL K2 power connector, then
the KPA100 RF amplifer section is not powered and the K2/100 will operate at
the K2's original, QRP TUNE and OPERATING power settings. In this mode, the
K2/100 still uses the SO-239 RF connector.

73,

Lyle KK7P

[c***@extremezone.com]

Post by Lyle Johnson
With the KPA100 installed, the K2/100 has a TUNE power level of 20 watts.

Thanks Lyle - now, what does this mean as far as amp draw while tuning and
using an external power source? Will it cause substanially less usage time then
stock K2 with internal battery? In other words, if I operate all QRP in the
field with the K2/100, but use more power to tune - how much will that shorten
battery life? Assume that I don't get carried away with tuning for purposes of
this question hi hi. Thanks for your help. 73/Tim

[Lyle Johnson]

Hello Tim!

Post by c***@extremezone.com
Thanks Lyle - now, what does this mean as far as amp draw while
tuning and using an external power source?

The K2/100 doesn't have an internal battery. A K2/100 will draw about 150
mA more than a standard K2 at all times, regardless of the power conenctor
used, because of the control circuitry that is running in the KPA100 module.
The bias current of the PA transistors adds about 400 mA to the transmit
drain if power is applied to the KPA100 power connector - not if power is
only applied to the normal K2 power connector. All of which are partly why
I made up my K-Twins :-)

I haven't measured to see what the current drain is like if I run the K2/100
at reduced power and comapre it to a K2. Maybe someone else has...

72/73,

Lyle KK7P

[k***@ENTERZONE.NET]

Post by Tim and Nancy Logan
Now I'm getting confused again :-) With the KPA100 INSTALLED in the K2
and the KAT2 removed, my understanding is that it will tune and transmit
at QRP levels (under 5 watts) as well as the 100 watt level - both using
the same external tuner to be released in September. DO I have this
right? Thanks folks. Tim NZ7C

If you're talking about using the KAT100 as the external tuner, YES. You
have it right. *MOST* other external autotuners will work as well. Of
course, your milage may vary depending on the amount of RF drive each
tuner requires to do its thing.

I am seeing a bunch of questions surrounding the QRP mode and QRO mode
symantics in regards to the K2/100.

Here is the simple explaination: It's a 100w, variable power rig. If you
have the power control set over 20w and you hit the TUNE function, it will
TUNE with 20w unless you bypass this protection. If you have the power
control at LESS than 20w, it will tune at whatever power you have
requested with the power control.

The fact that the KPA100 is put in bypass at levels below 11w seems be
what is confusing people. Folks, it is done to conserve power and make
the rig more efficient. It has absolutely NOTHING to do with the use of
an external autotuner.


So, if you want an "all in one package" with RIG and AUTOTUNER, build
yourself a K2 with the KAT2. If you want a QRO rig, build yourself a
K2/100. If you want a QRO rig with the autotuner BUILT IN, *BUY* yourself
a TS-2000. (It is a nice backup rig for the K2!)

73 de John - KC4KGU
K2/100 #2490

[k***@ENTERZONE.NET]

Post by Lyle Johnson
With the KPA100 installed, the K2/100 has a TUNE power level of 20 watts.
It has an OPERATING power range from 1 to 100 watts. Of course, once you
have activated TUNE, you can turn the power control up or down to change it,
but the next time you activate TUINE it will again be at 20 watts.

The K2/100 will *ONLY* go to 20w on tune *IF* you have selected GREATER
than 20w on the power control and then activated TUNE. If you have
selected less than 20w with the power control knob, TUNE will use whatever
power you have selected.

73 de John - KC4KGU
K2/100 #2490