This is interesting for me since I've had multiple troubles with CATV
hardline center conductors eaten away. On this particular antenna run, I
am using an old Heathkit antenna switch with over-the-coax control. So if
an antenna is selected other than the off state, there is voltage on the
coax. The center conductor is copper covered aluminum. After a few years,
I would find that white crystal powder where the center conductor had
dissolved. For about 20 years now, I've kept the control box off unless I
am at the station and have not had any further problems. At the same time
I doped the inside of the connector with silicon grease.
No hard evidence, but certainly a data point.
Jim - KR9U
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> I also read rumours last year from a Belgian or German guy who was
> wondering about DC always being on a coax line and his corrosion that
> ensued. This intrigues me as up until today I have had that RCS-4
> coax switch on pretty much 24/7-365 for years and years, only turning it
off if I am on vacation.
> A little voice inside my electronics head has to wonder if a small DC
> current on that coax for many years has contributed to my 'current' mess.
> (no pun intended)
>
>
- I was led to believe a little current flow kept corrosion away.
- Messing in the two way radio game for lots of years and dancing with
telephone companies over leased control lines to remote base stations, we
specified ?sealing current?. Since there was no ?talk battery? voltage or ?-
ring voltage? to keep the connections clean.
- The base stations were low level tone control and just audio up and back.
No volts.
- If the phone guys swapped pairs to fix something and didn?t look at the
original order to put the current on the line, it wasn?t long before it quit
working.
- I?ve fixed a few, just having them put the juice back on the pair.
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