Topband: [TowerTalk] Capacitors To Tune 160 Vertical

[Jim Brown]

On Thu, 29 Nov 2007 12:15:26 -0700, David Gilbert wrote:

>I'd probably shoot for more margin on the parallel portion than on 
>the series portion

Thanks for the many excellent thoughts on this issue. Based on the 
contents of my junkbox, I began with two .0047 400V dipped micas in 
series, and pumped 1 kW through them for a few minutes. They got 
warm, as one would suspect, but no sign of overheating. 

Returning to the junkbox, I found enough of them to build two 
parallel legs of four series .0047's. I'll smoke test that for a 
while before ARRL 160 this weekend. In the meantime, I'll also put 
together a parallel combo and have that waiting if and when the 
smoke starts. :)

Luckily, the feedpoint of this vertical is at ground level and only 
30 ft of coax from the shack. I've been tuning it with a TenTec 
229B, and that works. And it's easy to transmit for a while, then 
run outside to see how hot the caps are getting. 

73,

Jim Brown K9YC