Thanks for your reply and explanation of your "footswitch mod" circuit Don. It makes perfect sense now that you've elaborated on the functionality. And I can see how putting a properly wired sequencer between a foot switch and the "footswitch mod's" PTT input would protect my amp.
I simply misunderstood the function of your mod. I thought the "footswitch mod" activates the K2 and/or XV50 keyline without producing rf. Based on that (wrong) assumption, I expected the XV50 "Key Out" port to enable my amplifier after I pressed the foot switch. I'll build up a sequencer and wire it in. Tnx & 73, Lenny W2BVH On 1/13/2012 7:43 PM, Don Wilhelm wrote: > Lenny, > > The W3FPR "footswitch" mod should work with the XV50 just like it does > with the base K2. > The K2 cannot be keyed until the "PTT" line to the W3FPR circuit is > closed. > The XV50 will be keyed as normal by the K2 firmware through the cable > between the K2 and the XV50. You should have NO connection to the > XV50 Keyin line. > > Maybe your calling my circuit the "footswitch" mod is your problem - > it is really PTT for CW, and will do the job if it is connected > correctly into the system. You need to have a sequencer. The > footswitch (or whatever other switch you choose) starts the sequencer > chain - the first output from the sequencer isolates any preamps, the > second output activates the amplifier, and the third output goes to my > circuit to make its "PTT IN" input active. > That last action will then allow a dot or dash key closure into the K2 > - the K2 in turn will activate the XV50. > > If your problem is on SSB rather than CW, and you use the PTT line in > the mmic jack, you may need to make one additional change to the K2 - > open the PTT line before it gets to the SSB board. You can normally > just not put the PTT jumper on the mic configuration header, and then > run a wire between the mic jack PTT pin to the DOT input of my W3FPR > CW PTT circuit. > > 73, > Don W3FPR > > On 1/13/2012 6:50 PM, w2bvh wrote: >> HI! >> >> If you have a K2 / XV50 combo and have interfaced it to a power >> amplifier I'd like to hear from you on how you did it and what pitfalls >> you might have encountered. >> >> I've got a 6 Meter KW amp that I'd like to hook up to the K2 /XV50 and >> I'm concerned about possibly hot switching the RF on the output side of >> the amp with its 25 mS rf relay. The amp is switched active by grounding >> its keyline input. >> >> According to Elecraft, RF is only delayed by 3 mS from when the rig is >> keyed and as stated above, my amplifier output relay takes 25 mS to >> switch. >> >> I tried adding the W3FPR footswitch mod to the K2 hoping it would do the >> trick. It works just fine when the K2 is set for any of the HF bands, >> but it doesn't seem to have any effect when using 6 Meters. Its possible >> that I implemented it wrong, but I don't think so because it does work >> OK without the XV50. >> >> Ideally I'd like to have a set-up where the K2, XV50 and amplifier could >> be thought of as just a single high power transceiver whose band switch >> has been set to 6 Meters. >> >> Any experience you've had doing a setup with the K2, XV50 and a power >> amp would be very much appreciated. >> >> 73 >> Lenny W2BVH >> ______________________________________________________________ >> 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 >> > ______________________________________________________________ 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
