6500 with kpa 500 no power

Salty Z

Have used this combo for ft8 with 5 watts from 6500 and getting about 90 watts from kpa 500 and good band switching

tried ssb 20m for the first time and could not get any amplification from the kpa 500 using either vox or ptt with good mics; all settings according to flex and elecraft specs; kpa 500 will band switch fine but cannot get any power output even raising amp input to 10 watts

any ideas would be greatly appreciated

Greg K4GAZ

KD0RC

HI Greg, check your Transmit Band Settings to be sure that the 20 meter PTT line is selected for the line that you have connected to your KPA 500. I have a 6400 and use TX1 for mine. I am not sure of the configuration of the 6500, but the concept is the same.

Mike-VA3MW

As always, a screen shot of SmartSDR tells an amazing story.

Also, include a screen shot of your TX Band settings.

Does Tune work?

73

Salty Z

tune does work

KD0RC

It looks like you have DAX turned on in the TX pane. I think it will work if you turn that off. I would not select HWALC. With the Flexicraft combo, just set the radio RF Power such that you do not drive the KPA 500 past 500 W or so. There are some threads on this forum discussing why not to use ALC.

Salty Z

turned off dax and all hwalc- no change kpa shows no power running up to 25 watts input with both ptt and vox

Greg K4GAZ

Salty Z

just tried tune with kpa 500 on operate and it showed 40 watts out with 4 watts in

no changes with vox or ptt nothing on kpa 500 doing these

K0FLY

I just came in the read the mail.

Since tune appears to work, it appears that your not driving the KPA in SSB. As you speak into the mic, do you see any indication on your "LEVEL" meter. If not, you may have selected the incorrect input for the mic in SSDR (BAL versus MIC inputs).

Back out side to work on the antennas.

Gayle K0FLY

K0FLY

I just looked again, you have PC Audio selected in SSDR. Is you mic connected through the PC. If so then the problem is most likely in the PC set up. If the mic is connected to the radio then un set the PC audio button.

Gayle K0FLY

K0FLY

Disregard my last comment. My Bad

Gayle

Craig_KØCF

Your mic gain (the top slider in the mic control panel) is set to zero. You can't get audio from the mic to the radio until you adjust that so that the meter indicates a level up near -5 dB. You should then see RF output on the Flex, to whatever level you have the power output set to.

73, Craig KØCF

Salty Z

Gayle, no pc audio is not selected; when i push vox or use ptt i do see a signal in the level window; looks like the kpa 500 does not respond to either vox or ptt but why?

Greg

Salty Z

did have the mic level set low and putting it up did increase the audio output but still no response from the kpa 500

Greg

Salty Z

Craig, thanks for the pickup of the mic gain; raising it had no effect on the kpa 500 output=0

Greg

Salty Z

I was looking at the dax panel and do not see the red transmit signal with or without dax enabled; however with dax on there is no visible level in mic panel; the software manual says that you should be able to switch rapidly from digital via dax to ssb even with dax enabled

See section 35.1.6, DAX TX Channel and Microphone Interaction, for information about coordinating DAX TX channel usage with microphones. 

NOTE: If the DAX button above has been selected and PTT is initiated through CAT, audio will be used from the DAX source rather than the currently selected microphone input. If, however, a microphone PTT is depressed, the selected microphone will be used for input. This allows the operator to switch between a digital audio source and voice audio quickly.  

Salty Z

Well the Friday night gremlins left and all is working now; go figure

Thanks to all for your advice.

73 Greg K4GAZ