Copyright Kent Royce (Rotorgraph)©2011.
I decided to keep all my call signs to use under different operating conditions. I am interested in anything aerial related. I have made over 20 HF wire aerial over the past couple of years. I find aerial experiments great fun and you can learn a lot from testing and trying different configurations. What may work for one location may not be the same at your QTH.
I am now using a 200ft doublet fed with 80ft of hme
brew 2 ½ inch spaced open wire feeder. The doubler is at a height of
45ft with the ends at about 25 ft. a shallow inverted V. This is my main
station aerial and it performs very well on 40mtrs, 80mtrs, and 160mtrs.
No
tuner is need on 80 and 40.
I built another inverted L recently thinking
that the vertical section would work much better than my doublet. I was
mistaken, I spent a whole day laying out counterpoise wires and earth mats with
chicken wire and I am talking 140ft x 40ft here so it was not a quick job. I
erected the L and connected everything up to a fresh length of 213, apart from
a bit of trimming off the L all was good the analyser showed it was resonant on
1.950 MHz with a low SWR so off we went to do some
tests.
Well the results were not what I expected, but then when playing with aerials it seldom is. I was down on my transmitted signal by 4 s points compared to the doublet but at the time the received signal was quieter and down by the same amount.
I carried out some tests on 160mtrs over the next few days & nights. The facts were obvious the inverted L is good on 160mtrs but not great, maybe if I had a longer vertical it might improve the performance but I was limited to a 55ft vertical section. The doublet has spoilt me and I hadn’t realised it.Goodbye inverted L.
The doublet is noisy or should I say it is very good on receive because everyone is s8+ and the noise level is always around the s7 mark so it does bring in the noise but its ok and its the best so far so it’s up to stay at the moment. I say at the moment because I like everyone I am still looking for that holy grail of aerials.
I also have a full size horizontal loop for 80mtrs; this is only 10ft high
off the ground. This runs around the perimeter of my garden and is fed with
coax at the back of the shack. Performance seems good; I know it’s a bit vague.
“Seems good” but the 80mtr band conditions have been terrible lately so
comparing it with the doublet has not produced any definitive results so far so
the tests continue. Watch this space
I am not a DX chaser I don’t like doing the old 5 & 9 reporting I prefer an honest report and a good rag chew. I also have an NOV for 60 metres so please listen out for me on 60 metres
Radio Repairs
If you are looking for some where to get that radio fixed, old or new I can recomend
Radio Repairs .
Barry offers a professional servcice and very good rates.
email: radiorepairs@btconnect.com
Call: 01807 580376