by Charles Brabham N5PVL
Many Hams have expressed frustration when trying to tune HF packet signals, if their TNC lacks a tuning indicator. This article describes the use of a PSK31 soundcard program's "waterfall" display as great tuning indicator for any HF packet TNC.
Any PSK31 software will do. For the purposes of this article, I used the excellent multimode soundcard program, MixW, in psk31 mode.
To set this up, first you must tune in a packet station "the hard way", by guess and by gosh... But this will be the last time you will have to do it!
After you have an HF packet station tuned in, set up a speaker so that you can hear the packets being recieved. Now, set up your soundcard program to work with your computer's microphone, and put the mike near your radio's speaker. You should be able to view the packet bursts on your waterfall display.
Now, use your mouse to move the programs "pointer" so that it is centered up in the middle of the packet bursts. - Almost as if you were using the program normally. Note the place on the waterfall display's scale. In my case, it was at "8.2" on the scale... This will vary, according to your TNC, so find the place where your TNC receives well on the scale.
Now, leaving the marker on the scale as a reminder, tune slightly away from the signal. - Then turn the dial slowly, not looking at the radio's freq readout but watching the computer's display instead, carefully move the recieved packet bursts on the waterfall display so that they are once again centered upon your marker. You should be receiving packets again!
Sure it's cheap, but what the hey! It's better than no tuning indicator at all. This simple setup has saved me a lot of trouble when tuning in HF packet stations... I hope it is as handy for you!
Note for HF digital net managers: This setup is useful for coordinating an HF packet network, as it shows off-frequency stations, or stations having some other problem graphically. If you run Mixw in HF Packet mode, thier callsigns will be listed in the monitor window above the waterfall display. Screen captures can document what you see, making resolution of problems much easier to accomplish.
Good luck! Charles Brabham, N5PVL
U.S. Packet
http://www.uspacket.org/