Audio recordings from 2019 VHF Simplex contest

The 2019 Ohio ARES VHF Simplex contest was a lot of fun for all of us that participated. The WW8TF/Rover crew is putting together some media for you to enjoy, and this post is the first of that media.

You can download a recording of most of the traffic heard on in the contest here as a 35Mbyte MP3 file. Right-click..Save..As to download the file to your computer.

A few caveats with the file

  • This is the first time we’ve tried this, so it isn’t perfect
  • The levels are a little hot
  • The recordings were made from a Yaesu FT-8900 scanning most of the simplex frequencies used in the contest on 6m, 2m, and 70cm, and both sides of the dual band radio were scanning. This means sometimes you will hear two QSOs at the same time. There’s good and bad to this – and maybe next year I’ll record them as left and right channels
  • Since the radio was scanning, you won’t always hear complete QSOs
  • Silence was removed from the file as the recording was made, so the recording from the 6 hour contest is only 4:50:00 long
  • It’s a little long to listen to in its entirety, but it is useful to scroll through quickly or play back at double-speed to get through it

Recordings were made from Rittman, OH EN90cx from a Diamond V2000a antenna up 25′ with the base at 1148′ ASL.

If you’re interested in doing something like this yourself, it was done by wiring the speaker output of the FT-8900 into the line-in on the computer’s soundcard through a 10k resistor, and then on a Linux computer with this command which limits slices to 15 seconds and trims off any silence longer than 1 second:

sox -c 1 -r 8000 -t pulseaudio alsa_input.pci-0000_12_00.3.analog-stereo ./rove-recordings/1.ogg silence 1 0.1 1% 1 2.0 1% trim 0 15 : newfile : restart

The resulting files from above were combined with this Linux command

cat *.ogg > ../combined.ogg

Then finally they were imported into Audacity on Linux, and exported as a 16kbps MP3 file.

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