Topband: Switch for 160 meter antenna

[Dick and Adele Bingham]

Regarding ==>

 From: topband-bounces at contesting.com
 [mailto:topband-bounces at contesting.com]On Behalf Of Ken
 Sent: Sunday, July 18, 2004 10:41 AM
 To: Topband
 Subject: Topband: Switch for 160 meter antenna


 Hello,

 I am building a 160 meter vertical antenna, and perhaps incorporate
a 80 meter antenna within the same structure.

 I would like to switch out a top section of the of the antenna by
 means of a switch to break a connection leading to the rest of the
above antenna circuit.

 I could easily do this with a relay, but I don't want to rely on any coil
failures either due to voltages drop out or weakness of the coil of the
relay.

 What I would like to fine if possible, a type of wiper or knife  like
switch that can be activated by a servo or similar type mechanical
devise.

 Does anyone know of such a switch, and where to fine it?

 Thank you,
 Ken
K3YI
==============================================
Several things come to mind using sliding metal collars or coaxial tubes
with spring-finger-stock contacts (like the coil-shorting structure in a
screw-driver-antenna) that could be mechanically positioned to connect/
disconnect the various sections.

The mechanical driver could be:

-  pulley-rope driven where the conducting collar has enough weight to allow
   gravity to position it across the junctions with rope pull-back
disconnect.
   This would be external to the conducting sections and could jam during
   freezing WX if rainwater was present in the sliding gap.

-  again a sliding collar with spring-finger-stock inside the vertical pipes
and
   held in position in the upper-section by a spring. A rope exiting from
the
   bottom could pull the sliding tube-contactor down to connect the sections
   together. This would be a weather-proof installation and most likely free
   from frozen water jamming.

-  a pressure or vacuum driven plunger - or a motor-driven screw - to
position
   an internal sliding switching collar or a coaxial combination of a
finger-stock
   lipped-pipe receiving an insulator-led section of smaller conducting
tubing. The
   insulating guide section could be a section of hard-wood stock boiled in
paraffin
   or Teflon partially inserted inside the sliding contact.

73 de Dick - W7WKR
Stehekin, WA