[Elecraft] 2 meter amp for K3 or KX3

[Jim Bennett]

I second Joel's comments - it is a fun amp to build and operate. I put mine together last year and it has been a nice addition to my station. I drive it with my K3.

Jim / W6JHB


On   Wednesday, Apr 16, 2014, at  Wednesday, 11:28 AM, Joel Hallas wrote:

> The problem with most 2 meter "brick" type amplifiers, is that while they
> may have an "SSB" switch position, it generally only changes the TR
> switching method, and doesn't make them linear. The only medium-power 2 M
> amp I found that was linear, while we were testing them for QST was the
> Tokyo Hy-Power 300 W amp, that was in a whole different price category from
> the bricks, until they discontinued it.
> 
> While transmit linearity may not be a big deal for casual operation, the
> consequences of transmit IMD for other folks in busy areas during a VHF
> contest (about the only time people around here are on 2 M SSB) can be as
> severe as on the HF bands. Since I couldn't seem to generate any interest
> from Eric and Wayne in offering a suitable amplifier, I commissioned Jim
> Klitzing, W6PQL to come up with a lower power version of his excellent 2
> meter kilowatt that he published in QST. He did, and you can read about it
> in:
> 
> May 2013 - QST (Pg. 30)
> Build a Linear 2 Meter 80 W All Mode Amplifier
> 
> It can put out 100 W on CW, 80 W on SSB, with HF like IMD. It is fairly
> simple because it is based on a single amplifier module, and costs less to
> build than a brick. For this application, you can eliminate the automatic
> switching circuitry, although it doesn't take much, and then can be used
> with your FM handheld. It doesn't include a preamp because the K3 has a
> better NF than most preamps.
> 
> It can operate at almost any input level (including that of the KX3 2 meter
> mod, I believe) by setting the input attenuator. Because its current drain
> is less than the K3 during 100 W transmit, it can be run from the same power
> supply, since the K3 HF PA is off when on 2 meters. I have one and have been
> very happy with it. I believe Jim offers various parts kits on his website.
> 
> You do have to remember to switch it off when you go to 6 meters, since the
> amp quiescent current is high enough when the PTT switches to pop the PS
> breaker with 100 W on 6. You learn quickly.   
> 
> 
> Regards, Joel Hallas, W1ZR
> Westport, CT
> 
> 
> Subject: [Elecraft] Suggestions for a 2 meter amp?
> Message-ID: <1397611561586-7587334.post at n2.nabble.com>
> Content-Type: text/plain; charset=us-ascii
> 
> I installed the internal 2 meter module in my K3 so now I'm in the
> market for a good Amplifier to bring it up to at least 100 watts.
> 
> The K3 puts out 10 watts so the amp needs to be 10 Watts input
> 
> Any Suggestions?
> 
> 
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to w6jhb at me.com