We were reading GSM channels
with Tvoid software (
http://wiki.thc.org/gsm/tvoid) and at the beginning it worked fine. Suddenly, we do not how, it seems that noise level has increased
in 30 dB approx. and only a few GSM channels can be now identified (but
they are all only 10/15dB above noise power, when at the beginning
there was at least 40dB) but this channels can be read so we think the
front end is not broken, it seems the RF front end is not working
properly or its configuration is wrong, but we do not know how we have made it. We think that the LP filter in our dbsrx daughterboard may be working poorly. I attach you a screenshot of the best received GSM channel (it is only 15dB above noise power).
I expect your help
Thank you for your time.
Jose
screenshotgsm.png