[TowerTalk] 43' vertical mod for true resonance on 80M

[Mark Robinson]

----- Original Message ----- 
From: "Rick Karlquist" <richard at karlquist.com>
To: "Mark Robinson" <markrob at mindspring.com>
Cc: <richard at karlquist.com>; "Jim Brown" <jim at audiosystemsgroup.com>; "Tower 
Talk List" <towertalk at contesting.com>
Sent: Tuesday, 17 February, 2009 7:33 PM
Subject: Re: [TowerTalk] 43' vertical mod for true resonance on 80M


> Mark Robinson wrote:
>> I am planning something like this. What sort of capacitor do you need to
>> use
>> as the series feeding element.......a vacuum capacitor?
>>
>>
>> Mark N1UK
>
> I use WWII surplus "transmitting mica" caps.  If you want to make
> the antenna tunable, you can switch in various fixed caps.  A vacuum
> variable typically doesn't have enough capacitance, and in any
> event, you don't need the high voltage rating.
>
> Rick
>>>>>>>>>>>>>>>>>>>>>>>>>>>>

So maybe a polyester film capacitor? I imagine that the current is major 
issue in the selection of the capacitor here

Mark N1UK