I'm a new'ish tech ham (wanting to get my general) Just picked up a DXFT-3000 at a local hamfest, my 1st HF radio I just worked a "testing" local net on 6 meters with attic dipole (1.2:1 SWR) 53.770 FM 5W into repeater. feedback from net control , great signal, clear audio switch to 50.250 SSB 30W , feedback from net control , great signal, clear audio then to 50.400 AM 25W, feedback from net control , just carrier, no audio (I could hear net control and others just fine) Next day, went through all my Audio and AM settings, testing into a dummy load to an HT on 6 meters same thing, just carrier, maybe a crackle of audio, (monitor sounds good) 5W-25W power level testing so today, I tested AM on 40 meters into dummy load (I'm still just a tech, so no on air testing) HT had good audio on AM & SSB , so my issue is just 6 meters what am I missing ? looking for any suggestions to test/try .....
Check menu 053 AM MIC SEL. You have the option for FRONT/DATA/USB. Make sure it's on FRONT. Current Yaesu radios have a habit of remembering different settings per band, and that might account for why it's only 6m. Does it happen on 10m?
Did you try a FULL RESET on the rig? Modulation is all done in DSP, including AM, and it's curious it works okay on SSB but not AM. Still, before trying any further de-bugging, I'd try the FULL RESET as instructed on Page 7 of the manual.
Thanks for the quick answers Yes, I did a FULL factory RESET, when I 1st power it up from the hamfest (to be sure I didn't have any old setting in the radio) Menu 053 , it is set to FRONT , I changed it to USB, saved, and Back to FRONT then saved (just to be sure all that was before I posted So I just hook my 200mhz scope to the dummy load, so I can see the signal @ 50.4 Mic gain to 5 just carrier, mic gain to 100, lots of audio movement on the scope, HT was just noisy clicks so I've set the gain to 50, and (Menu 052) , and scope trace looks reasonable and the HT will feedback on the mic Hard to tell audio quality on HT as I'm speaking and listening at the same time it may be the mic itself, going to another hamfest this weekend, going to get a better mic anyway I've attached the trace of me saying "test" loud and slow (052 AM mic gain 50)
So, it actually does work on AM! The scope trace looks like very weak modulation, though...25% or something. Wonder why it lacks modulation on 6m but not on other bands? Design flaw? I have no idea. There's not much AM on 6m nowadays anyway, but it would be interesting to find out why this is occurring.
