Topband: Voltage rating of matching capacitor(s)

[Pete Smith N4ZR]

My shunt-fed tower requires an Omega match in order to get a good 
feedpoint SWR.  My current Omega match has 3000-volt air variables in 
both positions.  I understand the calculation for the voltage across a 
single series capacitor, but not how to calculate it for this matching 
system.  I have never run over 200 watts to this antenna, and am 
wondering what will happen with QRO.  Can someone explain the calculation?

73, Pete N4ZR
New Articles Daily - the Contesting Compendium at http://wiki.contesting.com
The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net

Pete Smith


On 7/23/2009 3:44 PM, Mike wrote:
> Great discussion, is there a good source of vacuum variables (at reasonable prices)
> for this application.  Everything I've found has been in the $300+ dollar range?
>
>
>
> ________________________________
> From: DAVID CUTHBERT<telegrapher9 at gmail.com>
> To: Roy<royanjoy at ncn.net>
> Cc: topband at contesting.com
> Sent: Wednesday, July 22, 2009 4:38:43 AM
> Subject: Re: Topband: T - vertical improvement
>
> The radial system you have will be fine. What you give up is matching
> simplicity. The T will need a base series capacitor as a minimum and an
> L-network if you like a 1:1 VSWR. At 1.5 kW the 370 pF cap will see 10 kV
> RMS. You are looking at a vacuum variable capacitor.
>
>
>      Dave WX7G
> _______________________________________________
> Topband mailing list
> Topband at contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
>
>