Just reading all of the comments on vacuum variables....... There are
many ways to do this...
I still believe in vacuum variables as they are essentially "foolproof".....
The good thing is that they can be remotely tuned using a 1 RPM 12 VDC
motor that is reversible by changing polarity. In my situation the
measured SWR is always flat at the rig and at the base of the tower...
http://www.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=cra201-nd
They'll handle just about any power level you can come up with to boot.....
A great source is MAX-Gain Systems here in Metro Atlanta (WB4GNT)....
http://www.mgs4u.com/RF-Microwave/vacuum-variable-capacitors-200.htm
He has a treasure trove of vacuum variables.... In addition, I have NO
financial connection to him...
*I GAVE UP ON AIR VARIABLES... They don't take the power well...
You will need a waterproof enclosure... Do it this way and you won't
have to go back later!!
http://www.mouser.com/catalog/catalogusd/645/2077.pdf
*
73,
John, W4NU
Atlanta
K4JAG (1959 to 1998)
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Topband Reflector
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