I have an old Alinco dual-band radio, the DR-600 (service manual) (manual)
I want to use this radio for receiving APRS packets. The speaker audio out Works but there are too many things to go wrong with Squelch, Volume knobs, or filter circuits designed for a speaker with a human ear which make a packet harder to decode with software.
I have looked through the service manual, but I don't really see anything that says "Discriminator" or "flat audio" on the schematic.
Where is the best place to pull audio for packet use on my Alinco DR-600 mobile transceiver? I would greatly appreciate pointers in the schematic to where I can test for audio sources.