[Boatanchors] How much is too much?

[rbethman]

The "old military equipment" with a neon bulb across the antenna input 
terminal to ground, is the precise description of the antenna relay 
"box" of an R-390A.

It certainly discharged the static buildup on the antenna.  I simply 
don't bet the farm on it!

Bob - N0DGN

On 1/29/2011 7:33 PM, Jim Haynes wrote:
> I don't know the answer, but the advice given about grounding all the
> receivers not in use sounds good.
>
> Even with tube equipment, you could get enough in through the antenna
> to burn an RF coil.
>
> I recall some old military tube equipment that had something like a neon
> bulb across the antenna terminal to ground.  Doesn't seem like that would
> limit the voltage enough, but maybe it did.  With more modern equipment
> you might put something like diodes in parallel across the antenna, which
> would limit the voltage to half a volt or so peak.  Will also generate
> cross modulation and possibly cause the receiving antenna to radiate
> harmonics of your transmitted signal, but will protect the receiver.
>
> I don't remember all the particulars now, but there was one time when
> I put a low-wattage light bulb in series with the antenna of a receiver,
> to protect it when my housemate was using his transmitter.
>
> You might want to study some Navy shipboard equipment, since that is a
> situation where they can't get the antennas very far apart.  Look at
> the web site http://www.navy-radio.com/manuals where there is a lot of
> material.