[Discuss-gnuradio] USRP1 Clock drift

[Matt Robert]

Hi Guys,

I ran Kalibrate against my pair of USRP1's using GSM900 towers (around
940MHz) and found my first unit to me 5kHz off and the second was 13kHz off.

Is this within limits for the built in oscillator? I have been using
them to transmit P25 frames around 435Mhz and found that my commercial
P25 radios will not decode anything coming from the second USRP. The
first USRP works OK. I have swapped around all daughterboards between
both USRPs and the only common factor is the second USRP motherboard so
I am sure its due to the clock in that unit.

Perhaps clocktamer or a secondhand GPSDO is needed for my Tx applications.

Cheers,
Matt