3.0.25 200Hz tone on AM

[W2PHL]

Hello, I've just installed .25 over .24. I'm hearing a constant tone at approximately 200Hz while receiving weak signals in the AM mode. It sounds like the same tone that occurs in SAM mode when receiving various amateur radio signals that have large differences in signal strength. From reading past posts, I believe Simon is working on the SAM issue. This is the first time I'm hearing the tone (some have called it a hum) in AM mode.

Phil

[Simon G4ELI]

Please add a screenshot - I can't think how a tone can be generated.

[W2PHL]

2020-10-02 07-04-58.mp4

(3.02 MiB) Downloaded 48 times

Please see the attached clip. The radio is a RSP-1A. The FDM-DUO showed the same result. The computer in the clip is running windows 7. I moved the radios to a newer windows 10 computer and the tone is gone. I thought this tone/hum thing was a known bug so I didn't look too deeply into it. I'll do more testing on the win 7 machine today. It could be an issue with the machine but it's weird how .24 and .25 are behaving differently.

[Simon G4ELI]

Why are you using a VAC? What's the audio like when using your speakers direct?

It's hard to see the signal with the way you have it configured, maybe open the IF display window?

[W2PHL]

NR2 is the issue! Nice and quiet with the noise reduction off...lol The windows 10 machine behaves the same way.
I use VAC to connect to OBS Studio.

[Simon G4ELI]

NR2 is the issue! Nice and quiet with the noise reduction off...lol The windows 10 machine behaves the same way.
I use VAC to connect to OBS Studio.

Ah, it's attacking the carrier I expect although I thought it was filtered out. Anyway - glad the issue is found, we hit this before and the NR2 tooltip does mention this.

[W2PHL]

I like the low setting on NR2. It cuts down on white noise/hiss without sounding watery. That's why I didn't realize it was enabled (I'm sticking to that excuse). Thanks Simon!