I am trying to get my head around calibration of my RTL dongle. I used
gqrx with a known frequency (467.6375Mhz). Based on this, the dongle
needs offset of -16Khz. In gqrx, this offset can be entered directly in
the user interface.
With rtl_test -p, the PPM number varies. I have gotten positive and
negative numbers.
When using the RTL block in gnuradio companion, I need to enter PPM. I
have seen various formulas to calculate PPM from frequencies but for me
they do not yield sane results. I could be just misusing these formulas.
Any assistance would be appreciated.
Thanks,
John
