OK, I've figured out the problem. I took a step back and realized I am spoiled by the close integration of the K-Line. The reason the FT101 can't key the amp is because, unless the K3S is turned on, the amp won't leave STANDBY mode.
Even with the AUX cable disconnected, the amp sits in STANDBY and pushing the OPER-STBY button doesn't do anything. I guessed a menu setting might control this, and setting the KPA Menu item RADIO to ANALOG now allows me to switch bands and from STANDBY to OPERATE via the KPA front panel buttons with the K3S turned off. A quick test shows 25 watts of tube-generated CW gives 450 watts output. Looks like I'm in business. Just need to change the menu item when I switch radios. Many thanks to all for the help! 73 de Chuck, WS1L chandler...@gmail.com On Fri, Feb 5, 2021 at 7:12 AM Chuck Chandler <chandler...@gmail.com> wrote: > Just tried it out - AUX cable removed, RF Input cable removed, RCA plug > with clip leads inserted in PA Key. Shorting the leads does not put KPA in > TX. > > 73 de Chuck, WS1L > > chandler...@gmail.com > > > On Thu, Feb 4, 2021 at 6:54 PM Jack Brindle <jackbrin...@me.com> wrote: > >> That is good. If you plug a pig-tail RCA jack into the KPA’s PTT input >> and short the wires, does the KPA go into TX mode? If so, the issue is in >> the transmitter or the cable you are using. >> You should do this test with nothing connected to the KPA’s RF input. >> >> As i noted in my post to the reflector, Fred Cady’s book has some very >> good info about this. Now if I can find it in my electronic copy... >> >> 73! >> Jack, W6FB >> >> >> On Feb 4, 2021, at 3:47 PM, Chuck Chandler <chandler...@gmail.com> wrote: >> >> Hi Jack >> >> It’s a Yaesu FT101ZD, and my multimeter shows it closes continuity >> between the key line center and shield on TX. >> >> No grid block keying! >> >> Chuck >> >> On Thu, Feb 4, 2021 at 18:37 Jack Brindle <jackbrin...@me.com> wrote: >> >>> Chuck; >>> >>> What is the PTT output from your other radio? It needs to be just >>> open-circuit, pull to ground on transmit. If anything else (I’m thinking >>> grid-block keying), then I predict a trip back to the factory for your KPA. >>> >>> There are two key lines coming into the KPA, and going through the KAT. >>> These are the AUX I/O PTT, and the RCA-jack PTT. They are maintained >>> separately through the Kat on their way to the KPA. Either can key the >>> KPA500, and both are opened by the KAT when it has high SWR or needs to >>> tune. The AUX I/O version is only meant be used with Elecraft rigs using 0 >>> - 5 signaling. The RCA jack is likewise meant to be used with rigs that >>> only pull the signal to ground on transmit, and leave it open on receive. >>> >>> Thus my question - what i the signal characteristic of the rigs PTT >>> output? >>> >>> 73! >>> Jack, W6FB >>> Elecraft Engineering >>> >>> >>> > On Feb 4, 2021, at 2:15 PM, Chuck Chandler <chandler...@gmail.com> >>> wrote: >>> > >>> > Just a follow-up to my question about using the KPA500/KAT500 with a >>> > second, older radio. I just finished some more testing and found that >>> when >>> > I remove the AUX cable from the back of the KPA and try to put the KPA >>> into >>> > TX with the keyline, it stays in RX. >>> > >>> > A continuity tester confirms the rig keyline is closing when the rig >>> is in >>> > TX, and the KPA shows driver power output, as does the KAT. But, the >>> KPA >>> > won't switch to TX and amplify. >>> > >>> > Is there some other function keeping the KPA in RX even though the AUX >>> > cable is disconnected? >>> > >>> > 73 de Chuck, WS1L >>> > >>> > chandler...@gmail.com >>> > ______________________________________________________________ >>> > 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 jackbrin...@me.com >>> >>> -- >> Sent from Gmail Mobile Chuck Chandler chandler...@gmail.com >> >> >> ______________________________________________________________ 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
