Messing with aerials
Around the time I was writing the last issue, I decided to try out my
six metre beam, which has spent the last ten years languishing in the shed.
Now testing such aerials in the past has entailed a rather tricky assembly of
stepladders and rubber bungees, so this spring I dug a hole next to the shed.
A steel pole was inserted inside, and steadied with a mast bracket screwed to
the shed. The hole was filled with concrete, so I ended up with a hand
rotatable mast base.
I mounted my six metre beam on a six foot length of aluminium pole, and
planted this into the top of the steel pole. The idea was that I could adjust
the gamma match while standing on the shed roof. This I did, and worked a
couple of Portuguese stations who conveniently popped up on the band.
I did have a problem deciding which was the front and back of the beam, and
the wind tended to blow the affair in the direction it wanted, which didn't
help. However my neighbour was rather upset by the assembly, even though it
was only 15 feet off the ground.
So I marked the gamma match settings with a felt pen, and dismantled it, with
the intention of fitting it to the main mast later on. I've not got round to
this yet.
The next aerial I had to evaluate was my dual-band 28/50 mobile whip. I can't
remember what make and model it is, but I fitted an old mobile mount to the
six foot ali pole, and screwed it in. This was fitted to another similar ali
pole, and stuck in the top of the steel pole. So the base of the whip is
about 21 feet off the ground.
Well, the whip didn't match up very well on ten metres, until I added a
quarter wave radial. On six it matched rather well, so I left it up for a
while, and it's still there. It seems to function rather better than I
expected. Sky-wave signals do not have the same polarisation as when they
left the antenna, so I reckon the fact that everyone uses horizontal
polarisation is not a big drawback.
The vertical obviously has less gain than the most basic beam. It seems to
work like a dipole, although it's not quite long enough. But the results have
been quite promising, in fact most stations I called came back to me, even in
modest pile-ups.
As I don't use any HF bands, I had a bit of trouble identifying some of the
stations. Where was OM3EY, T97V, and YL1AP? What are all there EH calls? It
seems that all the countries which broke away from Milosovic's Yugoslavia now
how new prefixes like S, OM, 9A, but whatever remained still uses 4N, YT, YU,
etc.
There are also a lot more countries on six than 10 years ago. I've added a
few more to the list, including Poland, Estonia, Slovakia, San Marino,
Ireland, Spain, Latvia, and Austria. Also I've found new squares in Germany,
Belgium, Switerland, Italy, France, Norway, Sweden, Faroes, and Denmark. I
have heard some Americans at good strength, but the pile-ups were amazing.
This cycle has not been very good for 6 metre enthusiasts, and only the
amateurs who eat, sleep and breathe six metres have worked much F2 DX.
However there is much to work with E layer range. A good few hundred locator
squares are on offer, although not enough countries for DXCC. Perhaps if I
can find the BBRC award rules I might put in an entry!
So although I didn't get to put my beam up, I've been quite pleased with what
I have achieved with the simple whip. It's a relatively cheap antenna, just
21 feet of pole and the seven feet of steel whip. It can be erected in the
smallest space, and takes very little time to put up or take down. It doesn't
seem to be affected much by high winds. Maybe I can find some more poles to
get it up a bit higher for next year.
|