Topband: Fw: 25G insulators

[Tom Rauch]

I have something on my web page about voltage and bandwidth of gamma
matches.

This is similar to the "loading coil thing", where voltage across any series
reactance is a function of current through the reactance. Current is uniform
as long as the component is small in terms of the wavelength, and has some
load of substance (less than a few kilo-ohms reactance or resistance)
connected to the other end.

With 1500 watts from a 50 ohm line into a series capacitor, line current
(5.5 amperes) times reactance equals RMS voltage across capacitor. A 300 pF
capacitor set at 120pf (736 ohms X) would have 5.5*736=4040 RMS or 5724
volts peak.

Voltages are almost always LESS in series fed towers, and bandwidth is
substantially wider.

In either case other antennas can be mounted on the tower.

If a tower is grounded, by all means shunt feed it. If it is or can be
easily insulated, there certainly isn't any compelling reason to shunt feed
it.

73 Tom