HF Projects

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This page will be filled in more once I have finished some of the projects and have photos to upload.


For constructing antennas I usually model my ideas in EzNEC to get an idea of characteristic impedance and Far-Field Radiation pattern. However I don't trust the exact wire lengths given in EzNEC, as there are too many real-world factors for this to be accurate.


As my main HF antenna I have used a full-size G5RV, this is currently in storage but I hope to retrieve it this summer! It is a multi-band antenna but does require a tuner.

Off-centre-fed vertical dipole

A brief attempt at feeding a 20m dipole at 200 Ohms with a 4:1 balun. Ended when I cut the wire too short while trimming and couldn't get better than 1.9:1 SWR (after a retrospectively good-enough 1.3:1 on the first attempt!).

Portable car-mount antennas

A plan in-the-making to use my 10m fibreglass telescopic fishing rod to support resonant vertical wire-dipoles (one at a time) for 6m, 10m, 20m. With the help of a radial kit, I should also be able to do a quarter-wave for 40m, and perhaps a rubber-duckie-style quarter-wave (with a lot of coiling) for 80m. All this will be mounted vertically on my car roof-bars for portable operation - the exact mounting method is currently under design..



This is my main HF rig, it is second-hand, has been kept in great condition and still puts out >100W with the original set of tubes.

Softrock RXTX SDR Transceiver

I've built a Softrock RXTX Ensemble SDR transceiver kit for my Dad that apparently works perfectly, I am now in the process of building another for myself.