Page 1 of 1

RPi iGate Kal not lfinding GSM signal

Posted: Sat Mar 12, 2016 3:49 pm
by g7kse
I've been following a few tutorials to get the dongle to be used as an iGate on a raspberry pi. see herehttp://www.w4dv.org/wp-content/uploads/ ... TL-SDR.pdf

Everything seems to go ok but there is nothing being returned when I try and use kal to listen to a GSM900 signal that I know is good and strong (I can see the mast and know its a GSM900 tx) here's the output

Code: Select all

Found 1 device(s):
  0:  Generic RTL2832U OEM

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
[R82XX] PLL not locked!
kal: Scanning for GSM-900 base stations.
GSM-900:
I'm not too concerned that pll lock is not working but also a bit concerned that there seems to be no audio detected. Any suggestions?

Re: RPi iGate Kal not lfinding GSM signal

Posted: Wed Mar 23, 2016 6:04 am
by rtlsdrblog
Have you tested that you are receiving the signal properly with a program like GQRX or SDR#? Check to see if the signal look good and strong, and not overloaded first. If its too strong it may not work.

PLL not locked is a normal error, it just means that that particular frequency could not be locked, but it will move on to a nearby frequency that can be locked.

Also kal will not output any audio, its a tool for finding GSM stations, and also determining the PPM offset on RTL-SDR dongles.