For best Q, the coil should have a single-layer winding, be as large as possible dimensionally subject to the requirement that its self-resonant frequency be well above the operating frequency, and i
I assume that the balun in question is a coil of coax. If foam coax is curved too sharply, its center conductor will migrate, or flow very slowly, through the foam until it shorts to the braid. This
How about adding a capacitor to the relay-coil-driving circuit (and probably another diode or two, depending on the circuit) so that the voltage applied to the coil initially, to pull in the relay, i
It's intuitively obvious (as my engineering professors used to say) that adding very-slightly _slack_ guys to a self-supporting tower can do no harm, and that when the wind blows they will help. They
1. I agree with Yuri and Chris (and, IIRC, Bud Hippisley, K2KIR) on this basic technical issue. 2. I said as much in a brief post of my own before either had posted their comments. However, this is n
The usual recommendation is that (1) the line should be fairly tightly twisted to maintain balance and reduce coupling of its transmission-line mode to other conductors; and (2) it should be separate
It is true that if you have an open or short circuitat the far end of the line, and if the transmission line is lossless, then VSWR is infinite. However, it is not true that the forward power, or the
The best way, which has worked extremely well for me with a 40-m half-wave antenna, is as follows: As a combination balun and impedance transformer, use one-quarter wavelength of roughly 600-ohm open
1. Download the Fair-Rite catalog from <http://www.fair-rite.com/>. It contains detailed specifications of many, many types/sizes/shapes of materials/cores/beads/rods/etc. Your cable beads are most l
Five hundred feet is enough separation that your problems shouldn't be too bad. If necessary, there are several solutions that the big multi-transmitter contesters use. One is to control your rigs by
In Maryland a magnetic compass needle points to the west of astronomical ("true") north. IIRC, when I was a Boy Scout in Baltimore, the deviation was more like 13 degrees than 10 degrees. Check it on
What Jim says is quite correct for consumer-grade (basically, inexpensive) GPS receivers, including both handhelds and those intended for use on boats. AFAIK, an LCD-displayed arrow that points north
The pattern of a G5RV on 20, 17, 15, 12, and 10 meters can be made nearly omnidirectional by leaving the central 20 meters (of the overall wire length of 30 meters) horizontal, and dropping the last
I _like_ seeing real ham antennas, towers, and related stuff being offered for sale, even when I have no immediate interest in buying them. It's useful to maintain a sense of what's out there, at wha
In most discussions about the consequences of high SWR, and perhaps in this one, forward power is confused with _net_ forward power. By _net_ forward power I mean forward power minus reverse power. E
All this sounds good to me. I don't know the W9INN balun, but I'd follow the manufacturer's instructions (the Towertalk Prime Directive). Grounding the balun may help to divert common-mode current fr
There's a _lot_ of good advice about not only how to approach your neighbors but also what to say in front of your city board, in Fred Hopengarten's (K1VR) book _Antenna_Zoning_, published by the ARR