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Reception drops off after a few mintues?

Posted: Wed Mar 20, 2019 11:52 pm
by mjsturing
I got my RSP1A and I've been playing around with it. I've found that when I'm listening to AM radio, it plays for a while and then it stops receiving. The signal goes flat across the display except a spike in the middle. At the same time, FM stations that come in fine normally get static. I can only get the strongest FM stations clearly after the first few minutes. When exploring the spike in the middle of the display, I found that it is always in the middle no matter what range of frequencies is on screen.

Short version, after the first few minutes a spike appears always in the middle of the display and every signal gets very weak.

Has anyone else seen this before?

Re: Reception drops off after a few mintues?

Posted: Thu Mar 21, 2019 8:50 am
by g1hbe
The spike in the middle is the local oscillator and is normal, but it should be well-suppressed (ie only small) when everything is working normally. As for the other problem, I wonder if your PC is lacking enough 5 volts on the USB?

Re: Reception drops off after a few mintues?

Posted: Thu Mar 21, 2019 5:02 pm
by Mike2459
Maybe you have a flaky antenna connection?? What is the S-Meter value when this occurs? Does it change as the signal fades out? Note: the S-Meter value will decrease when you narrow the bandwidth.

Re: Reception drops off after a few mintues?

Posted: Thu Mar 21, 2019 7:55 pm
by mjsturing
I'm not thinking it's a USB power problem. I've tried plugging it in to a phone with an adapter and charger, and the signal always seems weak, with just a spike in the middle from the beginning, but it's hard to compare different apps with a beta driver on the android device. That should be 5V/2A and the phone charges fine while it runs.

I don't think the antenna connection is the problem either. If I stop the software for a while and restart it, it runs again for a few minutes and then goes quiet. It's too consistent to be a flaky antenna. The S-Meter is usually just below a 9, and I've noticed it rises a bunch if I touch the antenna. When it goes quiet, the S-Meter drops to just below 7, and it no longer moves when I touch the antenna.

Re: Reception drops off after a few mintues?

Posted: Thu Mar 21, 2019 8:51 pm
by Mike2459
It sounds like the problem is internal to the SDR.

Re: Reception drops off after a few mintues?

Posted: Thu May 09, 2019 12:01 am
by mjsturing
So...I think it was an electrical problem with the house! Fixed now =)