Category Archives: Modes

The best Digimodes: Test reveals surprising results

Disturbed

Digital communications with digimodes is a very efficient tool of HF communications. Hams are using RTTY for decades. Since the advent of PSK31 in late 1998, there have been developed a lot of digimodes with special applications in mind. Albeit, RTTY and PSK31 are still very popular.

When I asked myself: “What’s the best mode?”, I couldn’t get a reliable answer. And, really, it depends.

As a result, I made a setup for testing some chat modes on HF channels which are very much different from just flat noisy (AWGN) channels. The results were very much surprising: There are by far better alternatives to RTTY and PSK31 (see table above, reflecting some of the results).

This paper deals with setting up a real-world testbed and presents some results. Anyone is welcomed to replicate the test and/or extend it with other modes. Recent software of W1JHK has made the workflow much easier and faster since then.

FUNcube Dongle PRO: How to get the most out of it, HF-wise

DynamikFCD_E

FUNcube Dongle PRO is an USB stick, containing a great SDR at a low price of around 200 Euros. It makes a fine choice if you are seeking a serious start into the world of HF & SDRs.

I had much fun in gettingout the most of it regarding the HF bands. My enthusiastic experience resulted in this paper: 16 pages with 43 figures showing how to use this great little SDR in receiving, decoding and analyzing. Many aspects are covered, with broadcast, Amateur Radio and Utility DXing only some of them.

The key success factor in the congested HF bands is shifting the quite limited dynamic range to it’s proper place (see Illustration from the paper on top). This simple technique results in stunning reception of even Decoding delicate digital signals of 2.400 baud out of Tahiti in Germany!

This paper explains in detail on how to get the most out of this receiver.

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