SSB Distortion on 10 Meters only 6400

Geoff AB6BT

Hello,

Last night I received a report that my audio was distorted on 10 Meter SSB. I verified that was the case by listening to my singnal with FDX. I was transmitting on one slice connected to a dummy load with the transmit power set as low as 1 on the power slider. I listened on the the receive slice connected to RXA. My audio was in fact quite distorted.

I checked using the same proceedure on 12M, 15M and 20M. The audio was clean.

It sounded like RF but I'm not sure if that is possible with such low power levels. I have done no troubleshooting yet. I will check all my connections when I can.

Anyone have any insight regarding or tips on what I should look for?

KD0RC

Hi Geoff, that is usually a sign that your transmit audio level is too high. Try again and check to be sure that the peak indicator of the Level meter does not go red. Do the other bands use the same Mic Profile and TX equalizer settings?

If that is OK, try again with the TX equalizer turned off. If that fixes it, it means that you are probably setting some values of the equalizer fairly high. Move all sliders down the same amount until none are over 0 dB. That should cure the issue.

If none of that is the issue, it is probably time to submit a help desk ticket.

Geoff AB6BT

Hi Len,

The TX EQ was off, I checked with the audio slider almost all the way down so I was just barely seeing a signal on the mic level meter. The audio was still distorted. All was good on the other bands even with full power into the dummy load and the mic level at normal setting.

KD0RC

Hi Geoff, I think I would submit a help desk ticket. Nothing else comes to mind that would cause this.

Mike-VA3MW

Before you submit a helpdesk ticket, you should do the following:

• test with the hand mic that you received with the radio
• make sure you have the correct Mic input selected
• turn off all TX EQ (done)
• watch the Mic Level meter and make sure it is less than -5db on voice peaks (done)
• Lastely, back up your profiles and reset the radio -- test again

If after a reset the problem is still there please open a ticket.

Good work on having a dummy load and lowering your RF power. Excellent debugging.

73

Geoff AB6BT

Hi Mike,

I've tried all the steps you suggest except using the stock mic and resetting the radio.

I'll try that this evening and report back.

Geoff AB6BT

Mike,

When attempting to do the factory reset I never see the LED/Button change to white. When I press and hold the button (Green) it flashes about 15 times and the radio powers off.

What next?

KD0RC

Hi Mike, you need to press and hold the power button from the off state until it turns white.

Geoff AB6BT

Of course... in a hurry sorry fo the false alarm.

As a test I did a quick record and playback in FDX and the audio sounds fine. But, it still sounds distorted in headphones while listening in FDX while transmitting.

That may indicate another problem. I will try a QSO on 10 Meters with someone local to get an over-the-air report.

Geoff AB6BT

Tested today with QSO to VK2. He reported audio was clean. Further investigation required.

John KB4DU

try transmitting into a dummy load while listening on the headphones. If voice is ok, it’s probably rf getting in when using an antenna.

Geoff AB6BT

Hi John,

As I mentioned in my OP I was using a dummy load for testing. I just had a OSO on air with a local station . I was running about 600 watts and he reported that the signal was clean.

So, 2 mysteries...the station who originally reported the distorted audio???, and why do I hear it only in headphones while listening FDX???

I'm going to call this resolved as there is no problem with my on-air signal.

Thanks all!