I have 2 Nooelec dongles that were modified with an improved LO. From what I can see they don't drift. Using SDR# I tuned each dongle to a strong frequency that I could confirm in the RR database. Centered the signal as best I could and used rtl_eeprom to record the ppm correction in each dongle. From what I saw the corrections were 52 and 60 and (to me) seemed stable over time.
When I spark up Trunk88 it seems to disagree with my notions and sets the ppm correction at 60 and 72 (respectively). So I took the ppm correction numbers from Trunk88 and used them in Unitrunker and it seemed to work well, I would even say that the DSD+ decode on the digital voice comms was a little bit better.
So my question is... is a ppm correction value 'universal' across software programs such as SDR#, Trunk88, and Unitrunker or do each of these programs have their own notion of ppm correction?
When I spark up Trunk88 it seems to disagree with my notions and sets the ppm correction at 60 and 72 (respectively). So I took the ppm correction numbers from Trunk88 and used them in Unitrunker and it seemed to work well, I would even say that the DSD+ decode on the digital voice comms was a little bit better.
So my question is... is a ppm correction value 'universal' across software programs such as SDR#, Trunk88, and Unitrunker or do each of these programs have their own notion of ppm correction?
PPM Correction Universal?
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