Flexradio 6400 and 6 meter FT8

Mark Griffin

I notice that for some reason on 6 meters my power output on FT8 seems to be low compared to the other bands I operate. My SWR is 1.11 and my input power is 75 watts. Yet, I only get 50 watts output running FT8. Is there some special setting I need to make to get this higher or what? When I operate 20 meters, I get with 75 watts about 65 watts output. I am using WSJT-X. I also tried JTDX and I get the same power output on 6 meters

David Decoons, wo2x

hi Mark,

Are you measuring with a steady carrier such as the tune button in SmartSDR? Remember, the TX band settings table under settings can have different tune power setting which are separate from RF power settings per band.

Next, if tune power is set to 75 for both bands and you are seeing a difference in power out into dummy load (65 watts on 20 and 50 watts on 6, then check you power supply voltage during TX with a program such as FRStack. Dirty or overheated Power Poles can cause this.

Next, if radio TUNE function works but WSJT-X does not, look at TX bandwidth and make sure Fake It is enabled under the radio tab in WSJT-X. If your audio tx frequency in WSJT-X is near the edge of your TX bandpass you can see low power out.

73

Dave wo2x