RTL-SDR - Progressive signal loss (PDW & HDSDR)

[dborg]

Hey All,
I use HDSDR + VAC + PDW to get my POCSAG messages decoded, however the signal gradually degrades over a week or two period to the point where I have to restart both HDSDR and PDW.

My antenna is a permanently fixed whip that is mounted indoors (which could be dealing with RFI from wireless routers, mains power, etc), but this still wouldn't account for as to why it would be a slow degradation.

I also have the system connected to a UPS and wonder that when it either self-tests or there's a brown-out or black-out and it's flipping to battery that the USB might be copping a power loss or the inverter inside the UPS might be creating a magnetic field that's mucking with it.

Any ideas on what might be a good place to start narrowing down or has anyone else experienced this sort of issue where signal rating starts to drop over a period of days/weeks?

Thanks

[Phil]

are you running other items on your computer. it is possibly a Memory Leak issue with the programming, have you considered SDRSharp

[dborg]

Very sorry for the late reply

are you running other items on your computer.

Yes and no, I only run PDW 3.2b01, HDSDR,VAC on this system but use TigerVNC server as it allows remote access with encryption.

it is possibly a Memory Leak issue with the programming

If anything is leaking I would be game enough to think it would be HDSDR, but even then I am not entirely on that path of thought.
When I see that the signal has failed all the way to unreadable the system isn't maxing out ram and the applications don't seem to be chewing more than usual.

have you considered SDRSharp

I used to use SDRSharp but find that SDRSharp doesn't auto play on application launch, so if the application or system crash and relaunch it won't start listening on it's own.

Thanks

[dborg]

Just an update,
I have noticed a pattern occurring. I went through 12 months of PDW logs and seeing that the capcodes that are coming up garbled are seeming to be in line with when I notice the signal loss and have not been able to identify where the cap code belongs to.

I am wondering if something in my set up might be to blame in terms of band width, calibration or antenna set up might be to blame (antenna is a 6db UHF whip and picks up south coast up to the hunter, while I am located in the middle of both).

I will try to keep digging.

I have also spotted an article online (a while back however), about how to reduce noise and interference with the RTL USB's.
The technique involved grounding the USB connector and introducing Ferrite beads on the coax. If I can find the article again I will post it's link.

[Boort8720]

Hi All,

In the last day or two, I have experienced severe signal degredation. It only appears to have happened after the EAS was shutdown for maintenance a few days ago. I have a 30 second audio recording of audio from SDR sharp that appears to 'skip' intermittently. I'm not sure if it's my CPU or something along those lines. I've also noticed that there is a low frequency, continuous tone being transmitted on 148.9125. I haven't noticed it before, but I'm sure that has nothing to do with it. Any help would be greatly appreciated.

Kind Regards,