SDRC Audio Distortion

[seca]

I just recently started playing with SDRs and I've had a hard time finding the source of this audio distortion in SDRC. I don't have this issue with SDR console. I uploaded a recording to yt so you can hear what I'm talking about, the recorded transmission starts at around 23 seconds in.

[G0OFE]

Cant see from the screenshot as to whether you have any noise reduction enabled.

For WFM reception, make sure noise reduction is disabled, as from experience it causes distortion to audio in that mode.

[Max]

I just recently started playing with SDRs and I've had a hard time finding the source of this audio distortion in SDRC.

Two things I see.

(1) Isn't Marine Band N-FM mode, not W-FM? 40kHz sounds like a very wide bandwidth?

but by far the biggest issue is.......

(2) You are trying to receive a relatively weak signal with the receiver tuned right on top of the centre "spike" that you will see with many analogue SDRs like the RTL-SDR. Move the active receiver away from the centre of the screen so that the RX is no longer sitting right on top of the centre spike. Easiest way to do this is left-click and drag the span slider at bottom of screen and slide it slightly to one side or the other so that the active RX is no longer right in the middle of the screen, thus avoiding the RX sitting on top of the dreaded spike. See picture of what to grab and move (slightly):

Span-Slider.jpg (11.55 KiB) Viewed 6576 times

Also like Jim says, check NR is off and also check squelch settings. We cant see either of these in the screenshot as you need to scroll lower down in the RX DSP panel on the left to see them.

Max

[jdow]

Um, if he really is using an RTLSDR dongle at 155 MHz he might also consider a modest change to the dongle settings. Set it to the VHF mode. You have it on the HF mode. Then set the sample rate at or below 2.4 Msps. That would be the radio's configuration selection in the ribbon bar shown. Finally boost the front end gain to 19 dB or so.

{^_^}