(snip)
> If this is such a great idea, then WHY don't those who make ant
> tuners putta 100K shunt across the ant inputs for precip static
> reduction?
One highly reputable manufacturer of transceivers DOES protect their
[transceiver] front ends. Their name is Ten-Tec! TT places an RF choke
across both the AUX and regular antenna jacks of their OMNI VI+. See my
earlier posting on this dated 09 October 1998.
Most manufacturers of linear amps also place an RF choke at the RF output
terminal of the amp to provide a DC path to ground in the event of an
output component fault which would put HV DC on the antenna. This also
serves as a VERY effective bleed for static charges when the amplifier is
in-line.
Placing a resistor at the antenna terminal of a tuner is NOT a very good
idea. Extremely high RF voltages can be present there, especially when
feeding a long-wire or any other antenna which is fed at a voltage node.
The cost of a HV non-inductive resistor which would handle the high
voltages encountered with even a 200 watt rig in such applications would be
prohibitive, and for a legal limit amp, unthinkable!
Collins used an 8.2 Meg IRC Type MVH-2 non-inductive resistor in their
military airborne antenna tuners (180L) for years. These tuners were
designed for use with the ARC-38 and 618()-series HF airborne radios (180
watts). If you purchase a surplus C501/180L capacitor assembly from one of
these units and are lucky enough to get one labled Mod-1, it will have the
2-1/2" tall x 1/2" diameter resistor mounted next to the VVC. The cost of
one of these resistors today is well over $100 in quantity!
73, Dave, K1FK
Fort Kent, ME
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