Late night edition.

It's been a long day here at Copper Mountain Headquarters!  So long, it's nearly eight o'clock that I am writing this.

The reason?  Well, that is a long story.  It started with my noticing the vertical delta loop was a little higher than usual in SWR during very wet weather.  It is usual for the matching to change a little in such weather, but now I was seeing 1.5:1 at 14MHz, and something similar at 28MHz, the first harmonic.

Eventually, I found a break in the wire near the feedpoint.  Nothing to complain about after five years or so of swaying around in the wind, often violently.

After repairing that, I applied the SARK analyser to the antenna, to find that, whilst 14MHz was now OK, 28MHz was way off, at about 2.5:1.

This is where things ended up wasting a lot of time.  I changed the homebrew 6:1 voltage balun for a commercial current version.  I knew this gave a higher resonance point, so I added a length of wire in the centre of the base (radial) wire until the match was very good at around 1.14:1 at 14MHz.

But sadly, 28MHz was still way out, although with a 300Ohm twin feed, this is of essentially no consequence as losses in the line are tiny compared to coax.  I just don't like using a tuner.

I then slowly came to realise, as the sun went down, that the original, homebrew balun could have water in it.  Any change in antenna characteristics should first cast doubt on any balun in use.  If only I remembered this at the time! I had taken a lot of time to make a high quality balun, but had somehow forgotten to put drainage holes in it.  I do use watertight boxes and a stone cover, but water always gets in slowly.

I opened the cover of the balun to find - yes, a pool of water in the bottom of the box!  Arrrghh!  I had wasted all that time matching the antenna to the commercial balun, and now I had to undo all the self-amalgamating tape, remove the long wire and restore the antenna to its original dimensions!

Anyhow, as it went dark, I had everything reconnected, weatherproofed and the balun covered with plastic and a ridge tile.  I also drilled small holes in the bottom that let water out, and only the very tiniest insects in!

SARKPlots sweep at 14MHz.

Same vertical delta loop at 28MHz.

The result is that I have, once more, a vertical delta with a 1.2:1 match across essentially the entire 14MHz band.  At 28MHz, normal operation, with a SWR lowering across the whole band, is restored.

Phew!  Now for some wine...