A single point disconnect that involves antenna, phone, and power, I
believe is a BAD idea. Because if its metal, it leaves the POWER ground
connected to the ANTENNA ground and connected to the phone line that may
be grounded miles away at the central office. Disconnecting radio
antenna and power does protect radio but leaves the antenna connected to
the power ground and phone ground to inject lightning currents into the
REST of the building. That can be hard on appliances and wiring. I
believe that the antenna system needs to be well grounded (including the
guy wires) but separated from the power and phone grounds except when in
use. I realize the phone wires aren't directly grounded but they are
"protected" by spark gaps with about 300 volts break down rating. So
when the antenna ground rises a few KV all but 300 volts get applied to
the phone wires.
I say, keep them all separated except when in use. And I believe (from
experience) that separation should be a minimum of a couple feet. My
house and station suffered much damage when the separation was only
inches. To meet my ideas, it require THREE isolated "single point"
disconnects. One each for power, phone, and antenna. Isolated from each
other and from the equipment and the house.
73, Jerry, K0CQ
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