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[aprssig] PIC processor for APRS info for D-STAR mobiles?

Mark Miller kramrellim at tx.rr.com
Sun Jul 6 11:09:01 UTC 2008


At 09:28 PM 7/5/2008, Wes Johnston, AI4PX wrote:
>Yes, I got a partial answer.  So does the low speed GMSK data 
>transit a voice grade repeater?  I know that afsk 1200baud packet 
>will.  Will the 4800baud digital voice signal do the same?

Wes,

It is possible for a GMSK signal to pass though a voice grade 
repeater.  I have tried this with MICOR, MSF5000 and Quantar type 
repeaters.  I am not sure if the GMSK was passed error free, but the 
error correction (for voice) built into the AMBE2000 codec seemed to 
handle any errors that were induced.  The part of the signal that 
seems to be degraded is in the low frequency spectra of the GMSK 
signal.  I have recorded GMSK using an ID=800 and an M-Audio Delta 44 
soundcard, and have played the signal back through the signal 
generator in an HP8920A  The results were similar to the repeater 
tests mentioned above.

73,
Mark N5RFX







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