[aprssig] A Closer Look at the WA8LMF TNC Test CD

[John Langner WB2OSZ]

How can we compare how well different TNCs decode less-than-ideal APRS
signals?  The de facto standard of measurement is the number of real-world
frames decoded from WA8LMF's TNC Test CD.

Let's 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.

WARNING!

This document contains images of really ugly APRS radio signals that some
will find disturbing.  Viewer discretion is advised.

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

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.