Radio coverage map verification with sound card logging.

The Dell Inspiron 5150 is so much faster than my old Toshiba Satellite for audio/video capture and editing as well as sound card amateur radio modes. I got a simple SoundBlaster USB soundcard as the ADC & DAC on the built-in sound card didn’t have the SNR I’d like. With the Firewire and PCMCIA slot, I can upgrade to home studio quality later.

With my Icom IC-725, PSK31 works quite well on the USB sound card–since I don’t want to splash 3 kHz at 10 mW of internal soundcard hash on the air. I have an NVIS dipole for 160-30m and vertical for 20m-10m. On CB 27 MHz it’s hard to talk to base stations 25 km away during the day–a striking difference from a few years ago when the sun was quiet. But this means a boon of DX on ham frequencies. I also have a lot of fun talking to visitors and travelers on FRS/GMRS. Of course virtually all are FRS but many are friendly and so surprised to hear a powerful base station talking to them. Living on the lake, I make some real long distance contacts to FRS units. I wonder how many more can hear me but I can’t hear them with a 10 dB (or so) power disadvantage.

Radio Coverage Map verification

A trivially easy way to test the range of such radios is as follows: put the base station into VOX mode, and setup the PC to play a tone N seconds long every M seconds. Then, setup the PC to simultaneously record continuously (or use a separate recorder).

Now you have a timed radio coverage system–synchronize your watch and PC clock. Then, even for the maximum range case where your base will hear the mobile but not be able to understand it, because you record your location vs. time in the car, based on the number of beeps you can match unreadable transmissions with where you were–which is often more important than where you can hear!

By employing such tricks, you can avoid buying $25K in logging gear–use your head and a pencil and pocket the difference!

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