[Elecraft] Amp for a K2

[Matt VK2RQ]

One other thing I forgot to mention, with KPA100, you get a KIO2 RS232 CAT interface "for free". I had to pay extra to add one into my QRP K2. Of course if you are swapping the top of your K2 to change between "QRP" and "QRO" modes, then you might want a KIO2 for the QRP lid anyway. Of course, you can run a K2 fitted with a KPA100  in QRP mode by powering it off the coaxial power connected instead of the Anderson power pole input, but then you won't have a KAT2 ATU, and will need something external.

Anyway, you can see we are spoiled for choices :-)

73,
Matt VK2RQ

> On 16 Nov 2014, at 7:09 am, Matt VK2RQ <matt.vk2rq at gmail.com> wrote:
> 
> I use the KXPA100+KXAT100 built in tuner with my K2, and it works great. Of course, the integration isn't quite as tight as it is with the KPA100+KAT100. For example, when I change bands, I need to hit the "dit" paddle to give the amp/tuner a squirt of RF and let it know my new QRG. But the tuner immediately selects the right antenna and recalls the last tuning solution for that band segment. I also set the power knob to 3W when doing a tuning cycle, and then maybe crank it up to 5W if I want a full 100W out of the amp.
> 
> In order to make the amp work the the K2, you need a key out line. The basic K2 doesn't have this, but it is easy to add one. Here is what I did, based on an article from the Elecraft website:
> http://www.mwrs.org.au/2014/04/20/elecraft-k2-amplifier-keying-circuit/
> 
> The benefit of using KXPA100 solution is that I can leave it at home if I want to take my K2+built in QRP ATU out into the field, or I can bring it along. I can also use the KXPA100 with my KX3, in which case it is a fully integrated solution. The KXPA100 is completely silent, with no fans, and relays only used for antenna selection/tuning/protection, whereas I understand the KPA100 has some noisy fans when it warms up.
> 
> Whichever way you go, the K2 is a lot of fun :-)
> 
> 73,
> Matt VK2RQ
> 
>> On 16 Nov 2014, at 6:33 am, Ken Miller <k6ctw at earthlink.net> wrote:
>> 
>> All,
>> 
>> Have updated the firmware and put in the keying mods on my K2.  Also had
>> a friend with some great test equipment verify that the new keyinh
>> waveform is as it should be to prevent key clicks when using an amp.
>> 
>> Now the dilemma. Torn between the K2/100 amp, and maybe a KAT100 in a
>> separate EC2 case or a KXPA100.
>> 
>> I'd like to hear comments from those that have used the KXP100 with or
>> without the tuner to amplify a K2.
>> 
>> Are there any special considerations that need to be taken into account
>> when using the KXPA100?
>> 
>> How easy is it to add the tuner later to the KXPA100?
>> 
>> Thanks in advance for any/all comments.
>> 
>> 73 - Ken Miller, K6CTW   K2 # 455
>> 
>> 
>> 
>> 
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