> 2. Let me ask: How many people on this
> reflector who use wire feeders of any type have any form of lightning
> protection on those feeders?
I do. Two Jennings 75A @ 10KV vacuum relays form a knife switch at the
antenna feed point in my outdoor, motorized ATU. When the shack ATU
controller is powered on, the relays close. When I QRT, the relays open.
See my QRZ.com page for photo details of the relays in the ATU.
Approximately 80-feet of LMR-400 is run from the shack through the attic to
a homebrew motorized ATU located outside at the back of the house. The
coaxial line to the ATU point is bonded/grounded via a bulkhead and tied
back to the service panel.
Also, I'm not sure the use of open lines is any more susceptible to
lightning damage than coaxial cables. Some of us are used to seeing how
well a heavy-duty, well-bonded/grounded cable entrance bulkhead can perform
when using coax during a lightning event. But if the open line can be
remotely disconnected (and antenna grounded if that one's preference), I see
no reason why a balanced line cannot achieve the same level of protection
with little work. The argument sometimes heard is "lightning just traveled
a mile to earth, what's another couple feet when the line is disconnected?"
The answer is that it depends on how the line is disconnected.
I used to detest switching power supplies until I found a model that does
not affect my current station. For me, common household appliances
(switching wall warts, the DVD player, the switching PSU in my router, the
switcher in my stereo amp, and several switching devices owned by neighbors)
were all producing more RFI than the shack supply.
Adding a really good panadapter was one of the most rewarding days in this
hobby -- it was also one of the most painful after spending months
eliminating all the noise to achieve a flat scope baseline so that I didn't
see, nor hear the sequential; switch-mode "bumps" on the display.
Paul, W9AC
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