I have used W8FGU's amplifier keying system with a K2 and a KPA1500 and can say it works just as advertised. The KPA1500 output is in the 200 - 225 watt range on CW (as I remember -- I did the tests a few months ago), depending on band and K2 power setting; the TR switching time is fine for fast break CW; and there is no discernible attenuation on receive. The amp does not poll directly for frequency, but using N1MM and the KIO2 the frequency for logging purposes is there with no fuss. The installation is straightforward -- one small circuit board and then mount the board and an RCA jack in an existing hole on the K2 rear deck and it's on the road. Neat.
Ted, KN1CBR ------------------------------ Message: 14 Date: Sat, 29 Jan 2022 19:57:33 +0000 From: "Dave Van Wallaghen" <d...@w8fgu.com> To: KJ <kjp...@gmail.com>, "Elecraft Reflector" <elecraft@mailman.qth.net> Subject: Re: [Elecraft] KPXA-100 & K2 Integration? Message-ID: <ema7b36147-ff70-427d-bde8-abc60b6325ce@desktop-w8fgu> Content-Type: text/plain; charset=utf-8; format=flowed . . . There are a number of circuits documented out there for this purpose. I also sell a kit for doing this on my website: https://www.w8fgu.com/k2_trdriver.html. This circuit and kit was based on one produced years ago by Tom Hammond, N0SS (SK). If you have the K60XV module installed, then you can bring out the K60XV J2 pin 2 for this purpose. I am doing exactly that on my K2. I mounted an RCA jack on the rear panel and tied it to that pin. The above will allow the K2 to drive an amp, but will not get you much "integration". With our amplifier line, band switching can be automated with a dit of RF from the K2. But other than that, tight integration like with our newer transceivers is not there. The cables I am trying to develop will attach to the K2's KIO2 AUX I/O port and provide keying. I have prototyped one to work with the KXPA100 and it keys properly and allows RS-232 commands to pass through the KXPA100 from the PC for control of the K2 by software programs. The main issue with integrating the K2 with our amps is that there is virtually no codes space left in the K2 firmware for having it communicate and integrate with the other amps like it did with the KPA100. So, things like amp power output and SWR will not be reflected on the K2 like it does with the KX2 & 3 when used with the KXPA100.. . . ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@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 arch...@mail-archive.com