Strange behaviour on 20m
Posted: Sun Feb 07, 2016 1:32 pm
I've got a very strange problem occurring only on 20m (14MHZ). I haven't seen this occur on other frequencies:
The shape of spectrum and waterfall changes for some time (less than a minute) and then gets back to normal.
In that period, I can't receive anything. It's just noise.
It occurs with different behaviours and shapes and is not predictable. (I mean, I can't reproduce it intentionally. It's random)
I've uploaded some pictures of it: http://imgur.com/a/Y9VgM
My system info:
SDRSharp v1361 and HDSDR on a PC (Windows 7 SP1 x64)
ExtIO plugin installed: 3.7 (build 0109)
Installed API: 1.8.1
I'm using a 14MHZ Dipole as antenna and a shielded USB cable (with ferrite)
I can tune to local FM stations, commercial shortwave stations, local AM stations and VHF radio without problems.
I've tested all combinations of LNA and AGC (I usually use 1.536MHZ IF bandwidth and 2M sample rate and Zero IF)
Could it be a problem in the tuner? Because the problem shows only in a particular frequency.
I tested it on a tablet too (Windows 10 Pro 32 bit) but the results were similar to the PC.
Any ideas?
Thanks in advance
The shape of spectrum and waterfall changes for some time (less than a minute) and then gets back to normal.
In that period, I can't receive anything. It's just noise.
It occurs with different behaviours and shapes and is not predictable. (I mean, I can't reproduce it intentionally. It's random)
I've uploaded some pictures of it: http://imgur.com/a/Y9VgM
My system info:
SDRSharp v1361 and HDSDR on a PC (Windows 7 SP1 x64)
ExtIO plugin installed: 3.7 (build 0109)
Installed API: 1.8.1
I'm using a 14MHZ Dipole as antenna and a shielded USB cable (with ferrite)
I can tune to local FM stations, commercial shortwave stations, local AM stations and VHF radio without problems.
I've tested all combinations of LNA and AGC (I usually use 1.536MHZ IF bandwidth and 2M sample rate and Zero IF)
Could it be a problem in the tuner? Because the problem shows only in a particular frequency.
I tested it on a tablet too (Windows 10 Pro 32 bit) but the results were similar to the PC.
Any ideas?
Thanks in advance