I have #DireWolf packet software transmitting/receiving #APRS with a Baofeng UV-5R handheld transceiver, Easy Digi sound card adapter by KF5INZ, old Windows PC & fixed QTH setting. PC & UV-5R audio levels are touchy, so do not set them too high. Take the time to experiment with the audio levels. Decoding may not occur if the audio levels are set too high. Or, you may get a DireWolf error message: “Audio input level is too high. Reduce so most stations are around 50.” That is a bit easier said than done. One nearby digipeater generated that error message at an audio input level of 200, but more distant stations were down around 20 or 30. Just try to find a UV-5R volume level that decodes some APRS stations. Then test the results and try slightly lower or slightly higher settings to see if they produce better consistency.
Questions? Comments? Post on this site, or contact me at firstname.lastname@example.org. (P.S.– Easy Digi sound card adapters can be found on eBay.)