I recently upgraded my shack to an ICOM IC7300, which in the EU specification includes the 4 meter / 70MHz band. I do not have a vertical for 4m, or space for one right now, but had read about others using a small matching unit to provide the necessary match using the Diamond V2000, or Watson W2000, as my version is badged.
At the Mayo Amateur Radio Rally a couple of years ago, a NI ham, Tom Herbison, MI0IOU was selling an interesting kit for the Raspberry Pi. It combined an Analogue Devices Clock Generator (AD9850) and an RF power meter (AD8307) to give a programmable sweep generator & detector... commonly known as a Wobbulator. I bought one and had anenjoyable afternoon not long afterward building it. It was a relatively easy build, and I got some use out of it tuning some Band Pass Filters I had built for use on multi-station portable ops.
Now that the weather is improving, I decided to dust off the /P kit and ensure that all was working will in anticipation of getting some outdoor operation. I had bought a lightweight dual-band beam for this purpose so decided to put it on a pole and see how it performed.
During HF field day 2010, I had occasion to get some experience with the off-centre fed dipole, in this case, a commercially made unit from Buckmaster.
Prior to this, I had heard that OCF dipoles ‘are a compromise’, ‘are noisy’, ‘are deaf’, ‘have wildly varying radiation patterns’ and many other negative comments. During field-day, our experiences definitely gave me cause to doubt the nay-sayers.
We (the Galway VHF Group) have a good many portable operations coming up this year, so, to supplement our portable HF antenna collection, I thought a 20m Moxon might be a nice project.
The only real expense was the 4 fibreglass fishing poles, but they ended up very cheap, even when you factor in postage from the UK.
The design was going to be based around a spreader made from a rectangle of 12mm ply, with 25mm dowel bolted on at the relevant angles.
Finally, after freezing all Winter, I decided to do something a little more secure and warm about getting my various antenna feedlines into the shack. The previous attempt was so slipshod that I think the less said about it, the better, so we'll leave it there.