TT:
Here are the suggestions you have sent me on this subject:
O I have found automotive relays to be useful. There are some available
for switching high currents at reasonable prices. I would expect them to
have large conductor areas. Not sure about high power use though.
O I bought a dozen of the RTB14012F relays when they were a buck a piece.
Price is now over $4 plus S/H.
O The voltage at the end of the sloping wire is probably too high for the
contact to coil "withstand" of any reasonable 12V relay. You would probably
be better served to use a relay to switch a coil in series with the sloping
wire at the feed point on your tower. Most any "automotive" or other open
frame relay should work in that application. [AD3F: Others have advised me
of HV at the open end of the sloper element. The relays I checked all had
muti-thousand Volt withstand ratings between coil and contact.]
O You mean the extra wire at the far end of the sloper provides resonance
in the CW band. If you can bring the far end of the sloper near ground
level so it can be reached, you can try this method that I used. I
separated this wire with an insulator and used an alligator clip jumper to
connect it. That way, a relay would not fail. Remember, the far end of the
sloper is the high voltage point of the antenna, so if you used a relay, the
contacts would have to be rated for over 1000 volts if you are running high
power.
O When I've seen switching for band segments on 75M done at legal limit,
they use "medium amp" relays in boxes. If it is at low power then I think a
small ice cube relay would be fine. e.g. Deltrol 900 series.
O I have the same setup to switch my half sloper between 80 and 160. I
use a Jennings RF3A Vacuum Relay that a friend gave me.
I get the 26 VDC for the coil from one of those little Radio Shack 12V 2.5A
power supplies. They have 26 VDC inside, ahead of the regulator, so I just
brought it out on a pair of wires.
I'll let you know which I select and how well it works. Thanks for the
suggestions.
73 de
Gene Smar AD3F
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