[Amps] doorknob cap suppliers ?

Carl km1h at jeremy.mv.com
Sat Mar 19 05:20:30 PDT 2011


If the RFP doorknobs are the standard CRL/HEC HH-58 size there is no 
difference between the 5 and 7.5KV versions except for the label. Both are 
conservatively rated and just the overhead margin is different.

The weak link in that amp is the 160M switch contact to the frame screw as 
Ive mentioned earlier.

Carl
KM1H


----- Original Message ----- 
From: "Robert Harmon" <k6uj at pacbell.net>
To: "Carl" <km1h at jeremy.mv.com>
Cc: <dezrat1242 at yahoo.com>; <amps at contesting.com>
Sent: Friday, March 18, 2011 10:01 PM
Subject: Re: [Amps] doorknob cap suppliers ?


Carl,

I hear what you are saying on higher voltage caps and yes it is cramped, I 
checked the available room
and there really isn't any room for adding much larger caps.
RF Parts has some ceramic doorknobs in stock that look suitable.  They are 
2000pf at 7.5kv and they are about 7/8" in diameter. A pair of these 
conected in parallel would fit o.k.

No steel or stainless, I am thinking of using 3/8" wide copper strap for the 
doorknobs. I would love to find some
silver plated strap like the plate strap is,  but maybe getting too carried 
away.


Bob
K6UJ









On Mar 18, 2011, at 1:42 PM, Carl wrote:

> I see no reason to go higher voltage in that amp. Similar B+ level 
> products have been using the standard 5KV ceramic doorknob for many 
> decades. The antenna safety chokes are there for a reason and if there is 
> an antenna fault while transmitting saving the 8874's will be your major 
> concern....always monitor the grid current.
>
> With Russian caps you first need to have the room which is already 
> cramped, and metric brass or screws and washers....you arent going to use 
> steel or stainless are you?
>
> Carl
> KM1H
>
>



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