OBSERVATIONS GM1SXX
12 December 2010
Giving up fishing ?
It's said in some circles that a vertical aerial 'radiates equally badly in all directions', and the RCF seem to think that a vertical 'radiates equally well in all directions', this being the 'correct' answer in one of their exam questions, but of course, that's complete bloody nonsense. They should say that it radiates outwards equally well in all directions ,dependant of course on having an adequate ground mirror. Only an isotrope, impossible to feed, from a practical point of view, (in theory at least), radiates equally well in ALL directions. As I've said before, we need a better RCF, one that can word exam questions in a far more meaningful manner.
At home, I use a simple DIY vertical consisting of nothing more than a cheap fibreglass carp pole that's missing it's top sections, with a wire threaded up it. It's a resonant quarter-wave on 16.5Mhz, so it's actually too short on 20M and too long on 17M, the bands I use most. It's fed against some buried wires and bonded to our cast iron wastewater drainage system. It's also very close to a chain-link fence, which of course messes with the match and the radiation pattern. Considering it's extreme simplicity, I get out pretty well. I've worked into the USA, Sri Lanka, Israel, Norway and much of Europe with this simplest and cheapest of aerials. Despite it's failings, I've never had a problem with it. It's compact enough that the neighbours haven't even commented on it. I'm pretty sure that my grounding and radial system which extends over two gardens, helps it work acceptably well. I use it with an LDG Z-11 Pro automatic 'tuner', which again is, wrongly named.... It's NOT really a TUNER of course at all, but instead an impedance matching device, or 'aerial matching unit', or AMU. The truth is that the Z-11 PRO really just a simple computer controlled L-match.
A manual matcher, made from some common things like some solid-core wire, a variable capacitor,. a rotary switch and a varnished toilet-roll centre, could do just as good a job! You have to twiddle it though, to find an acceptable match.
In a few months of fairly casual operating with the plastic fishing-pole I've worked into BALEARIC ISL. CROATIA CZECH REP. DENMARK ENGLAND ESTONIA FINLAND FRANCE GERMANY HUNGARY ISRAEL ITALY LATVIA LITHUANIA NORWAY POLAND PORTUGAL ROMANIA RUSSIA (ASIATIC) RUSSIA (EUROPEAN) SERBIA SLOVAK REP. SLOVENIA SPAIN SRI LANKA SWEDEN UKRAINE USA .
I allow myself an absolute maximum of 40W output on PSK. To use any more is very antisocial I think, and especially if it causes splatter. Most of the time I run less than 20W and at times as low as 0.5W I've had a 599 report from Southern France while running 800milliwatts, so a lot of power is obviously NOT required for datamodes, even from my fairly lousy aerial. My main HF radio is an ancient FT-102, built sometime in the early 80's. I struggle at times to get a watt or two from a trio of 6146B's, but it CAN be done :-)
I seem to always have a path into the Black Sea area, which I find quite strange. In my log, European Russia has pole position, closely followed by Italy. I rather like working Russian stations because in the main, they are good operators. I've also worked many good Italian operators, and I should probably give Alessandro IZ0SAT a special mention because when I had a contact with Alessandro, BOTH of us were running QRP power into fishing poles! I don't remember there being anything at all difficult about that contact. There's a great deal of fun to be had by using low power and simple aerials.
I've had a huge amount of satisfaction from my deliberately poor aerial system and I've worked a little DX. At least I think 5843 miles counts as DX. I've worked into many areas of Europe on a regular basis. For sure you won't bust a pile-up with this aerial, but a little patience and good operating skill yields plenty of contacts.
I do plan to put up a somewhat better aerial soon. I do have just enough space for an Inverted L, and such aerials have served me very well in the past for portable operation. My next HF aerial will therefore be a home made trapped inverted L with an UN-UN at the feed-point, and fed against my ground system.
So, the fishing-pole *may* be taken down to make space for an inverted L but I have ordered parts to make yet another aerial. At work my office is six floors up and I think I may be able to launch a PSK signal from there using a couple of loaded 20m whips made into a dipole and fed from a DIY 1:1 UNBAL. I won't be able to run much power of course, but a few watts should do. I have an old ICOM IC-730 that I've repaired and which can be used from the office. Such a simple aerial, operated indoors, won't be a great performer but it WILL get a signal out and that's what matters. I'm looking forward to operating before work and at lunchtimes, from the office. I hope eventually to get permission for a full-sized 20M wire dipole on the roof.
I'll probably never give up fishing for signals with simple aerials. For me it's just far too much fun. A very modest system at work will probably be as much fun as the current setup. There will be new challenges of course, like the 2600 personal computers we have, and the fact that our server farm is directly downstairs from my office. Bring it on!
This may be my last posting before 'XMAS', so have a good holiday folks, and if you have the time, get yourself on the air! There's a lot of fun to be had.
73 Al
GM1SXX