Monthly Archives: September 2013

6m Loop Fed Yagi Project

A few years ago, I bought a 6m yagi from Moonraker and James and I used it on one of our private field days. We found it difficult to get a great match but I thought I’d resurrect the project earlier this year to enter some random Saturday contest that was taking place on 6m.

Unfortunately, for love nor money, although I managed to assemble most of the bits, I couldn’t find the gamma match arrangement in all my Tesco boxes. I needed this because unfortunately the impedance of a three element yagi is well under 50 ohms so unless I went for just a two element beam, I would have to re-engineer things. I recall that a loop had a higher impedance, about 100 ohms. Using a closed loop system with a reflector and a director would bring the loop impedance down, probably by about half (according to the modelling) to achieve 50 ohms. I modelled it and things looked very promising. Wide bandwidth and pretty good gain.

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Designing a Radio Ham Shack

I can’t remember how many times I’ve moved my shack around. And when I do, it’s always wrong, it doesn’t look quite right and nothing fits where it should.

m0mcx shack redesign

Further, just when / if I do manage to get it right, I need to get to a particular piece of equipment that’s stuffed away perfectly on a shelf. I seem to spent more time dismantling the darned thing to get the piece out to either take to a field day or have it fixed.

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511 QSOs – Cornwall DX-Fest Conclusion 2013

2 Weeks in Cornwall seemed to go in a flash but in between QSOs, I did manage to find time to repair my website and get it back and running again. I love documenting the fun and games I have whilst I enjoy the science of RF. I trust you enjoy it too.

cornwall qth

Firstly, thanks to everyone who gave me a QSO. I exclusively used a pair of verticals. Antenna #1 was the 40m vertical (actually 9.6m in length with 16 radials) which also gave me a 5/8th style antenna on 15m. Antenna #2 was the dual fed 20m and 10m verticals, similar to a fan dipole. More accurately I would call this a “nested” vertical.

I ventured onto 80m band for an hour but conditions were abysmal compared to 40m so you’ll see many of my QSOs were on my favorite band.

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