[aprssig] PIC processor for APRS info for D-STAR mobiles?
Mark Miller
kramrellim at tx.rr.com
Sun Jul 6 07:09:01 EDT 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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