Hello, ...a few days ago I spent 3 days out in the fields doing some antenna measurements with reference to a dipole at the same height and thought I would let you know the results. Initially I only
Hi Rick, I dont know about the Ham rotators, but at least over here spare parts for Kenpro/Yaesu rotators are QUITE PRICEY if you get them at all 73 Con DF4SA
The way I understand it, a voltage balun is a "REAL" transformer with TWO MAGNETICALLY COUPLED coils wound on a single core. The problem here is that many things can go wrong during the construction
Hi Jim, while training the feminine side a bit, would certainly be a good investment somehow, too... :-) ... you might want to check out the excellent FREE SOFTWARE "4NEC2" at: http://www.qsl.net/wb6
Hi Mirko, I would advise using the baloon approach only if you are on an open free field, without surrounding trees or bushes. Otherwhise the wind might very well push down your baloon for a short ti
Hello, As some of you might know, during the last years I have been experimenting a lot with lightweight antennas made from fiberglass and wire, to be used on various dxpeditions and portable activit
I can only second Peters experience and recommend you guys give polar plot a try, when trying to measure antenna patterns. I have recently used it myself and found int to be a very handy piece of sof
Hi, I very much liked W1HIS's detailed explanation as of what causes the velocity factor. However I would not say it does not matter much. As others have said, the rough value for the velocity factor
Hi Dink, you can mount them spaced 1foot apart, even feed them at a combined feed point, so you need only one feedline no problem at all I do it all the time with wire verticals on dxpeditions. 73 Co
Hi Jan just a few days ago someone on our local mailing list reported excellent results cleaning his traps with 10% sulphur acid. The acid does not corrode the aluminum any further, but cleans out al
Hello everybody, I want to EXACTLY measure the resonant frequency of a wire dipole. That means I cannot use a simple SWR bridge, because normally the resonance curve is so broad that I can only deter
Hi Art, I do not know for sure but I presume all of todays antenna analyzers measure SWR and absolute impedance value (mag Z). From these numbers they calculate the vector data (real and imaginary pa
Hi Sylvan, there is a graphic about this in the ARRL antenna book. The theory is easy: stay away from wire lengths that are even multiples of lambda/2 for the frequencies you are using. If the wires
hello..., i would like to ask the group wisdom for help on the following topic: having learned that the unterminated vee beam is bidirectional and therefore "wastes" radiated power into the backward
Hello Thanks to - Al and the others - for the fast responses. I think his answer (see below) pretty much sums up the post received so far... Well, I should have thought of it myself, that the resisto
the point about problems with (even light) wind is valid. I have tried such an antenna 3 times and always had problems with the wind bringing down the antenna. only use this kind of antenna when the
Hello Herb, as Tom already pointed out, a vertical is what best fits your description and very easy to make. For 40m it is about 30 foot high. Your 20 foot pole is a bit too short, but you can easily
Hello, a friend of mine is having problems with mounting a 3ele 20m Beam 6m (18ft) above a sheet metal roof. I was quite sure that would be enough separation, but the roof seems to greatly detune the
Good point on the stretching of ropes. I had to learn that lesson also when developing the spiderbeam My advise would be to use 2-3mm diameter Kevlar (Aramid) rope. This rope will have a breaking str
I recently have been asked a similar question by a friend who is trying to put up a 3ele 20m yagi 6m (18ft) above a sheet metal roof. The resonance (point of lowest SWR he measured with his SWR bridg