Some antenna projects begin with a carefully selected collection of specialist components. This one involved a chopping board, tent poles, shoe-rack tubes and a couple of wardrobe-rail holders.

The aim was a lightweight wire Moxon for 10 metres, designed around 28.500 MHz, which I could put up on my Spiderbeam mast. Making something useful out of ordinary household bits was part of the attraction.

[Photo: the Moxon on its mast, with the receive loop in the foreground.]

The centre: kitchen meets furniture department

A plastic chopping board forms the central plate. It provides somewhere to mount the four spreaders, attach the antenna to the mast and support the coax choke.

The metal tube rails from a shoe rack became sockets for the tent-pole spreaders. I secured these to the chopping board with U-bolts, arranging them so the pair of spreaders opening towards each short side of the Moxon rectangle had an angle of approximately 40 degrees between them.

The tent poles fit into these sockets and support the wire element assembly. The sockets made a useful way of turning a flat chopping board into the centre of an antenna.

For the mast mounting, I drilled a hole through the board and fitted a wardrobe-rail holder on each face, aligned with the hole. That gave me a central mounting through which the mast could pass.

Quite a lot of furniture hardware, considering there isn’t a wardrobe anywhere up there.

[Close-up photo: chopping-board centre, U-bolted sockets and wardrobe-rail holders.]

[Parts links: chopping board, shoe-rack tubes, tent poles, U-bolts and wardrobe-rail holders.]

Wire and feed

The elements are made from 1 mm wire, with RG316 used for the connection to the driven element.

On top of the chopping board sits a coax coil intended to act as the feedline choke: eight turns of Messi & Paoloni Ultraflex 7, approximately 12 cm in diameter.

That describes what I built. I haven’t measured the coil’s choking impedance, so I can’t give it a performance figure simply because the antenna has a good SWR.

[Close-up photo: feed connection and coax coil.]

The calculator was the beginning

I used a downloaded Windows Moxon calculator to obtain the initial dimensions, entering 28.500 MHz as the design frequency.

[Calculator name and download link to follow.]

A Moxon has a driven element and a reflector, with their ends folded towards one another. The gaps between those ends are part of the design, so there is more to adjust than the overall wire lengths.

In my case, there was a fair amount of messing about with all three: the driven element, reflector and end gaps.

The calculator gave me a starting point, but it certainly wasn’t a case of cutting the wire, putting it up and declaring victory.

One observation surprised me: adjusting the reflector affected the SWR more than adjusting the driven element. That was what I found while tuning this particular build, rather than a rule I’d expect every Moxon builder to follow.

After enough fiddling, I ended up with an SWR of about 1.2:1 around 28.500 MHz. Pretty good, and certainly good enough to stop adjusting things and get on the radio.

How it performs

The Moxon has provided some very enjoyable operating on 10 metres, particularly during openings towards South America. I’ve often found those openings around an hour before sunset.

Some of the larger Brazilian stations are undoubtedly doing a fair amount of the heavy lifting at their end, but it is still satisfying to make the contact through something held together with kitchen and furniture fittings.

It has also proved useful on 12 metres with a little help from the ATU. I’ve noticed directional behaviour there too. I haven’t measured the radiation pattern on that band, so I’ll leave it at an operating observation rather than claiming particular gain or front-to-back figures.

Would I build it again?

Yes. The combination of a chopping-board centre, shoe-rack sockets and tent-pole spreaders made a practical way to support a lightweight wire antenna.

The part that demanded patience was tuning it. Getting the driven element, reflector and gaps to work together took considerably more effort than the calculator’s neat dimensions might suggest.

But that is part of the pleasure of building antennas: start with a design, make it from whatever useful bits you can find, adjust it, and then see who answers.

In this case, some of the answers came from the other side of the Atlantic.

73, Kev — M7XOM