Very heavy distortion on Transmit - Hermes Lite - Resolved

All bug reports here please
bob edwards
Posts: 18
Joined: Sun Feb 14, 2021 9:34 am
Location: Chippenham, Wilts, UK

Very heavy distortion on Transmit - Hermes Lite - Resolved

#1

Unread post by bob edwards »

I upgraded from 32 bit Windows 7 to 64 bit Windows 10 in the summer. I can still boot up either. My hardware is:-
I7 desktop with old GeForce GT 450 dual monitor gpu. Hermes Lite 2 driving an XPA125B 100W linear. My recording tests today off Hack Green show:-

SDR Console 3.1 or 3.2 on Windows 10 - receive works perfectly, transmit very heavy dalek like distortion - disabling CUDA seemed to make no difference. The same distortion also shows up in a recording started from the SDR Console 'Record' button.
SDR Console 3.1 or 3.2 on Windows 7 - receive and transmit work perfectly
Thetis-HL2 v2.8.12 on Windows 10 - receive and transmit work perfectly

Any hints as to how to diagnose what's up, please? Cheers Bob G4BBY
Attachments
G4BBY recordings.zip
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Last edited by bob edwards on Fri Oct 21, 2022 9:06 pm, edited 2 times in total.

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: Very heavy distortion on Transmit - Hermes Lite

#2

Unread post by Max »

bob edwards wrote: Thu Oct 20, 2022 2:45 pm SDR Console 3.1 or 3.2 on Windows 10 - receive works perfectly, transmit very heavy dalek like distortion - disabling CUDA seemed to make no difference. The same distortion also shows up in a recording started from the SDR Console 'Record' button.
Any hints as to how to diagnose what's up, please? Cheers Bob G4BBY
Press Windows key on keyboard. Type "Run" to bring up the Run dialogue box.

Type "mmsys.cpl" (without the quotes) to bring up audio devices panel. Whatever source you have used to route the mic to the input of SDRC, make sure sample rate for both Playback and Record is set to 48kHz (to be found in the "Advanced" tab for both record and playback devices).

Try that. SDRC does not like 44.1 kHz sample rate devices on any audio source used to input audio to the TX DSP panel. If you are using a Plantronics USB connected headset, I think you may be out of luck, as another more knowledgeable person than myself says these models cannot be set to 48kHz sample rate, only 44.1?

Anyway, my guess is the sample rate for your main mic input device is set differently on your copies of Win7 and Win10. Obviously if it's an analogue mic into an audio card/USB sound card then it's the soundcard that needs setting to 48kHz.

73

Max

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: Very heavy distortion on Transmit - Hermes Lite

#3

Unread post by Max »

bob edwards wrote: Thu Oct 20, 2022 2:45 pm SDR Console 3.1 or 3.2 on Windows 10 - receive works perfectly, transmit very heavy dalek like distortion - disabling CUDA seemed to make no difference. The same distortion also shows up in a recording started from the SDR Console 'Record' button.
Any hints as to how to diagnose what's up, please? Cheers Bob G4BBY
Forgot to mention. Did you know you can monitor your TX audio chain using the Spectrum Scope (great for checking if audio is top-clipping) and the audio monitor buttons I've circled in the attached picture?

If you have the "TX" monitor button selected, you only here audio on the selected monitor device when you are actually in live TX, but if you push the "RX" monitor button, you don't need to actually TX to monitor the mic
(or other audio input source) audio. Obviously best routed to headphones but great for adjusting Proc and EQ etc. for optimum quality prior to TX

73

Max
TX-Spectrum.jpg

bob edwards
Posts: 18
Joined: Sun Feb 14, 2021 9:34 am
Location: Chippenham, Wilts, UK

Re: Very heavy distortion on Transmit - Hermes Lite

#4

Unread post by bob edwards »

Max, many thanks for all the hints. I found a fix for my problem

1. I found my microphone (a Blue Snowball USB mike) to be set at 48 ksamples/s as were my speakers in Windows 10, so nothing wrong there - BUT ...
2. I found normal mic operation returned when I set the mike to be 'Shared' under Audio In (Mic) -> Shared Mode -> Shared must be ticked - it only distorts badly if set 'Exclusive' (which I may have set at some stage).
3. Two other usb mikes seem to work shared or exclusive.

Thanks again for all the tips - cheers Bob G4BBY

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: Very heavy distortion on Transmit - Hermes Lite

#5

Unread post by Max »

bob edwards wrote: Fri Oct 21, 2022 8:33 pm Max, many thanks for all the hints. I found a fix for my problem

I found normal mic operation returned when I set the mike to be 'Shared' under Audio In (Mic) -> Shared Mode -> Shared must be ticked - it only distorts badly if set 'Exclusive' (which I may have set at some stage).

Thanks again for all the tips - cheers Bob G4BBY
No worries Bob. Glad you found a fix. That did not spring immediately to mind but now I think I've heard it mentioned before somewhere. One for the memory bank!

Also remember the three presets for audio-in on the TX DSP. I've got "Normal" (light proc and EQ), "DX" (with more proc), and the third, "Other" I have set with VAC in and out and no proc for digi modes FT8, VarAC etc.

All the best

Max

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