Weak Signal Digital Modes on HF-Bands

Many open source programs are available for Windows, OS-X and Linux, if you want to become active on the amateur radio HF bands using digital modes. Modern coding and modulation schemes allow for long distance contacts with low power.

Below you can  download my presentation about PSK 31 (Phase shift keying) and JT-65/JT9 modes as presented in our monthly SARTS meeting August 2016 in Singapore.

Presentation (pdf): WeakSignalModes


DU1- Dasmariñas – Aug 2016

This time we stay longer than a week in our second home, and I set up a 12 m fibreglass pole with a G5RV multi-band dipole antenna for 40 m to 10 m. The pole is located at on corner of our area, the dipole endings are fixed at two other corners, so the antenna has a form of a 90 degree inverted vee.

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fibre glass pole

The antenna analyser shows clearly 3 resonant frequency points: around 40 m, 20 m and 10 m. All resonances seem to be below the amateur radio frequency bands, probably because of the inverted vee form.


Using my “old” AT-130 antenna tuner, I can operate on all bands from 40 m to 10 m including the WARC bands.

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Assembling the antenna:

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Operation in digital modes using my home-brew interface:

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Time to disassemble, as we are going back to Singapore. Heavy duty 40 ft fiber glass pole and G5RV dipole:

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