You can silver or gold plate the hardware, but whatever you do DO NOT use a conductive goo....or any other type of grease...to flood a connector. The only thing you might want to use is a teflon pas
There are different worrys in different applications. If you only run a few hundred volts and the gap is large, even rain water works well as an insulator. For high-power RF, I'd seriously worry abo
Excellent idea: You can read SWR in the house. For control position, use pots. I think a screwdriver would be about right for a roller if it had enough torque, but would be fast for a air variable ca
Hi Eric, Several wire spacings, and you need to twist the line at small fractions of a wavelength to minimize pickup and radiation at higher frequencies. Nothing other than radiation losses at high f
Very interesting Tom. I am still trying to make 80 meter verticals that hold up well. I was thinking or irrigation tubing, but it is so soft and thin it scares me. I don't mind guying it, but instal
Hi Rich, It better be a darned big loop antenna to reach 90% efficiency, and far above earth! You should never interrupt the current path of a small loop with pressure connections, or a feed system.
Hi Mike, You didn't say for what frequency range, what impedance, and what power level. Without knowing that information, any answer is meaningless. 73, Tom W8JI W8JI@contesting.com List Sponsor: Ar
Probably not much, if the three vertical array is done correctly. Traditional 4 squares with 90/180 degree phasing are off a tiny bit in phase delay from optimum, so they don't work quite as well as
I use a bow and arrow, but I fill the last several inches of hollow aluminum arrows with solder inside the arrow by pouring molten solder inside the arrow. I use a dam made from a paper wad to preven
I'm not sure how well the Tennadyne antennas work, but one thing that bothers me is Tennadyne's feed system. They have two "hot booms", they put a balun at the feedpoint, then they run the coax back
There certainly is a lot of unusual antenna science! Another manufacturer claimed more gain than is possible with any combination of spacing and phasing using two elements. They "invented" a thing c
That is not correct Frank, the statement above illustrates a common misconception of what a balun does and where it belongs in the system. Baluns do not always belong at feedpoints, as a matter of f
I think it might be useful to point out that multi-lobe gain is not "free gain". Any gain from splitting an antenna's pattern into many lobes with many nulls results in an average gain, or useful gai
Any capacitor placed across a power line must be UL/CSA rated for line-bypass applications. The components are clearly marked with AC voltage ratings, and have UL/CSA and perhaps VDE logo's on them.
You are begging for problems. The relay is at a voltage point, and worse yet you have a vertical! The voltage can be as much as twice the voltage on a dipole at the end, assuming you have a good gro
Hi Ford, Voltage breakdown varies greatly with shape and rate of change in the electric field between the two conductors. I think the number you saw is for a uniformly distributed electric field and
You may have missed it Tod, but two solutions were given and rejected. 1.) The suggestion was offered and a working example given (along with a history of actual problems) of using a latching vacuum
There is something everyone should keep in mind with RF switches that are open, or have open contacts that are held at a different RF potential than the input, and connect to a structure up in the ai
There are problems with that. A few years ago, I measured the loss in ladder line in buried PVC pipe. I don't have that data handy, but the loss increase is very substantial. As I recall, placing th
The problem as far as I know is lightning. If the cables leave the tower above ground level, it is bad news for lightning protection. That's probably OK if the messenger cable does not attach to the