[aprssig] Dirty signals vs. hardware TNCs

[wb2osz at comcast.net]

Suggested reading on the subject.


Sometimes it's a little mystifying why an APRS / AX.25 Packet TNC will decode some signals and not others. A weak signal, buried in static, might be fine while a nice strong clean sounding signal is not decoded. Here we will take a brief look at what could cause this perplexing situation and a couple things that can be done about it. 

https://github.com/wb2osz/direwolf/raw/master/doc/A-Better-APRS-Packet-Demodulator-Part-1-1200-baud.pdf



Here, we take a closer look at some of the frames on the TNC Test CD in hopes of gaining some insights into why some are easily decoded and others are more difficult. There are a lot of ugly signals out there. Many can be improved by decreasing the transmit volume. Others are just plain weird and you have to wonder how they are being generated.

https://github.com/wb2osz/direwolf/raw/master/doc/A-Closer-Look-at-the-WA8LMF-TNC-Test-CD.pdf