Steve, If you want to avoid the high price of vacuum variables I would
suggest the much lower price of G2 or equal HV high current fixed micas
available on E-Bay. These fixed caps can be made essentially variable
by putting a series inductance like a hand wound taped coil of copper
tubing. You can also use a simple roller inductor to find the correct
march and then replace with a fixed inductor of a higher power handling
capability. Be sure you pick a value that is somewhat higher in
capacitance then you think you will need so the series inductance will
give you an adequate tuning range.
Herb Schoenbohm, KV4FZ
On 10/22/2013 9:33 AM, D. S. Coleman wrote:
GD All:
This winter, my shack will have a new heat and light source, thanks to
the warm glow of vintage 3-500Z's on Topband. :-) The downside is
that now my variable capacitors in the the omega match of my folded
monopole will not be up to that kind of abuse. I need to replace
those old cheese slicer caps with a couple of vacuum variables that
are 500 pF or so max and a voltage rating of 5 KV or better. Would
any of you gentlemen have any vacuum variables that you would be
willing to part with? If so, please reply off-list to my email
address below.
Tnx & 73,
Steve, AB4I
cwforever2@gmail.com
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Topband Reflector
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