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: <[email protected]> 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
