Don and Igor, I didn't think it out completely when I first posted. This is because this is the first time I will use a HF amp. VHF amps nearly all have RF sensed TR (Plus the means for PTT control). I do not like RF sensing as I can not see how one avoids hot switching.
MY system for running the HF amp will be using a good old toggle switch (same function as a foot switch). That will the K3 PTT (KEYIN) and the control the amp PTT (KEYOUT) before I ever touch the CW key. For SSB there is no issue since PTT switching will be accomplished before I speak (thus producing RF). I cannot use that for AM or FM but I have not used FM on 10m so not an issue (at this point). The only thing I will have to check is if paralleling my sequencer input with the amplifier PTT will cause any control issues (both using pull-up +13.7v and grounding the PTT line). Possible using some steering diodes will isolate them. I don't want to have to remember to switch over anything. On HF only the amp will use TR switching so pretty simple. I will not have to lengthen the TX-DLY. I haven't decided if I want to use inhibit for HF. It is implemented for VHF at present using the BAND0 control line to activate it. I will add BAND1 (for 222) and DOGOUT1 (for 6m) to add inhibit on those two bands. Probably do not need inhibit on HF (unless I am forgetful throwing the "toggle switch"). I have to do that for CW on VHF so probably become habit. This should take the old-timers back to the days where we used a toggle switch marked SEND on the old receivers which applied voltage to the old Dowkey coax relay. Those had aux contacts for grid-bias keying the old vacuum tubes transmitters. Ed ------------------------------ Message: 6 Date: Fri, 17 Feb 2012 07:55:20 -0500 From: Don Wilhelm <w3...@embarqmail.com> Subject: Re: [Elecraft] K3 TX delay Igor, I understand your situation, but the application of PTT does not produce any RF - nothing will hot switch. When you "hit the key" (or for SSB begin talking), then RF is produced. If you arrange your switching to be accomplished by either the PTT or the K3 KEYOUT, and leave the K3 in non-VOX state, there is no need to increase TX DLY to any other than the 8 ms default value and therefore no shortening of CW elements. 73, Don W3FPR 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-? DUBUS Magazine USA Rep dubus...@gmail.com "Kits made by KL7UW" http://www.kl7uw.com/kits.htm ====================================== ______________________________________________________________ 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
