Topband: Vacuum Variables

[John Harden]

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)