A little 6m work.

Well, it's not much, but it works fine enough.  The wire length was 1.37m per side for a SWR of just under 1.2:1.  Not that there was much to work - only Ireland and the Isle of Man today, with one PA station heard in rapidly changing, brief Es.

A multi-element beam and mast is on the list...

This is the HFTA gain prediction for the simple dipole, together with the terrain profile to the east.  Note the deleterious effect of the higher ground between me and the sea on low angle radiation:

At 4m above very good ground, the pattern, which is almost entirely horizontal radiation (blue), as you'd expect, is plotted below. MMANA-GAL reaches much the same conclusion about peak gain as the HFTA model does.  More height is needed, but it's fine for casual working, not least because 6m propagation is often binary: it's either strong or dead!

Field operations resume!

A few spare hours today saw a clear-out and check-out of the 'countryside shack' after the winter break.

The good old TS-480 worked without a hitch, as did the Raspberry Pi and its screen.

The loaded dipole, showing top disc end load.  Matches all bands 20-6m.

I generally now use the end-loaded vertical dipole, which is very useful in this period of variable and often unpredictable propagation.  Power is from a standard 70Ah car battery, which is fed by a 60W mono solar panel.

Though simple, the dipole gets out well.  Here are a few plots, starting with 20m, of FT8 stations hearing my 15W over an hour or so this afternoon.  I even managed a few reports on 12m (not shown)! 

Reception reports of FT8, 14MHz.

18MHz.

21MHz.

About 10 minutes' worth of 1W WSPRing, 14MHz.

Cow-proof antenna mount.

Well, spring has arrived in good fashion in Wales.  Although it's still cold, there's a lot of sunshine now, and trees are about a month ahead of their usual flowering time, thanks to several days of warm weather at the start of March.

Looks like a good year for Damsons!

Attention now turns to the 'countryside shack', which hasn't seen much use over the winter, except for some, ultimately unsuccessful, experiments with a Vee beam.

Most antenna work at the site has been with easy-to-deploy 1/4 wave verticals.  These work very well, but do tend to pick up a little of the RFI that my Raspberry Pi generates, although with some care, the effects can be reduced to negligible levels, even for WSPR.

Countryside shack.  Looks rubbish, works great!

But the main problem is the base mount for the variety of fibreglass pole-based antennas.  For a year, I've just used a semi-permanent fence post with a PVC tube attached to it.  I simply slip the pole into that, with no need for additional fixings.

The trouble is: cows!  They are very big, very heavy, and love rubbing and pushing anything they can find.  After months of this treatment, the fence post fell over.

The other trouble is dry weather.  The ground that is a muddy marsh in winter becomes rock hard as it dries out in summer.  This lets the fence post become loose, and also makes it impossible to drive the post further, or a new one into the ground.

My veterinary daughter, with the problematic animal type in the background!

So, how to provide a base mount that can easily be fixed and removed in any ground state, and that is also resistant to breakage by ruminants?

Well, I thought the best solution was to buy a good quality telescopic aluminium pole from Spiderbeam and attach a horizontal antenna of some sort permanently to it, putting the whole thing well above cow height.  But, the price!  About £400 for the 12 metre version!  For now, that kind of money just isn't justifiable. 

So, I came up with a simple solution to continuing with my 1/4 wave verticals and vertical dipoles: a £20 piece of 90-degree steel, 2m long, with a sharp tip cut into it.  This will go into any ground, as it can take some hammering if necessary without damage.  But to reduce hammering, I'm going to weld two foot rests, so that I can stamp it into the ground.  The antenna pole simply rests in the 'V' of the 90 degree angle, held in place with releasable cable ties or just bungee cord or string.

The image below is the kind of tip I will cut, but my mount is just one long piece of angle iron against which the antenna pole rests, rather than a base socket.

The mount could also be made of thinner, lighter 'Dexion' (shelving type) galvanised steel, or aluminium, if it's thick enough. Either way, this won't be damaged if I leave it in place and a cow pushes it over and stands on it. It can also be easily removed and replaced as a temporary mount.