Saturday 9 June 2018

How's your propagation?

So why go digital? Because digital sends data. And that data can be used for other purposes than simply having a QSO. For example the new FT8 mode both allows you to conduct a digital QSO in a minute or so, and build up a pattern of your propagation, but also using additional software gives you an insight into who you are receiving and where they are on the map.

What do you need?

First an SSB receiver (or transceiver), next an interface to get the audio in/out to your PC sound card. All pretty straight forwards and can be implemented with a cheap USB audio interface dongle. Then you need the software...

Software

WSJT-X first. You tune your RX to, for example 7074kHz for 40m, USB. The incoming signals of the new mode FT8 will display on a water fall (audio from 200-2000kHz adjustable). And every 15 seconds as others transmit you will receive their call signs, signal strengths and location.

Screen Shot 2018 06 12 at 08 41 08

See how the software is able to decode even the weakest signals (about 20db below the noise!)

WSJT sends out information packets by UDP to a local web address 127.0.0.1: 2337. This can be picked up by other software running on your computer.

GridTracker software picks up the WSJT packets, and plots the received station on a map.

Screen Shot 2018 06 12 at 08 43 53

That's a pretty good way of seeing the current propagation conditions.

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