Hi!
While doing my srsRAN config and solving issues one by one, I came across the general advice to have a GPSDO. Without this, it seems LTE communication may be difficult….
Well, now I have a Leo Bodnar LBE-1421, configured channel 1 to 40MHz, and prepared everything to change the resistors on my LimeSDR Mini 2.4 board…. but the resistors were not there, and I realized that this can be done by software on this Rev.
Fine… but how???
I came across this post: LimeSDR-Mini v2.4 - external clock
With this information, I thought, I could test my settings by getting a CW carrier from my R&S sig-gen into the RX and check the frequency in the FFT-Window of Lime Suite.
My thinking was, that changing the DAC value for the VCTCXO should not move the carrier if the external clock was working.
I tried everything..setting registers in LimeSuite, setting it on the cmd-line as suggested in the thread… nothing. Changing the cal-settings always moved the carrier.
Even using Kalibrate-lms did not show a difference with or without the GPSDO (and yes, I verified the signal and yes, I supplied the cmd-line argument!)
Software is self-compiled using a recent checkout of the master branches on up-to-date ubuntu 24.04.
I have the feeling that the reference-clock-settings are not processed somewhere in the srsRAN => soapy => limesuite chain.
Just for fun, I tried to feed it with 42MHz using all the different device_args parameters I found on the web. I hoped to see this reflected in the info-output of srsRAN, but it still stayed at 40MHz.
Anyone got a similar problem?
BTW I intentionally avoided putting my device_args here, because they are wrong for sure.
Regards!