[Amps] Hi-pot testing

Jim Thomson jim.thom at telus.net
Sat Feb 13 11:28:51 EST 2021

Date: Fri, 12 Feb 2021 17:39:46 -0500
From: Steve Bookout <steve at nr4m.com>
To: Amps at contesting.com
Subject: [Amps] Hi-pot testing

<Several months ago, I had a problem with a 40 year old HB amp for 160.? 
<Just sitting there, it started making an arcing noise (sort of) and 
<showed plate current jumping around.

<Now, I'm finally looking into it.? I'm using a HB hi-pot tester and am 
<testing pieces and parts up to their voltage rating.? FYI, the plate 
<voltage is 4 KV and most things are rated much higher.?? I was checking 
<things out at 5 to 6 KV with very minimal current showing.? Happy with 

<Question:? Someone once told me that new Eimac tubes were tested at 
<twice their rated voltage.? Ok, fine.? What about capacitors???? 
<So, what should it test if it were brand new?

<73 de Steve, NR4M

##  remove the  tube or  tubes...and see if any thing still arcs.  
If it still arcs with tubes removed, test just the HV  supply by itself, not 
connected to the  RF deck. 

## After  40  years  I would give it a good  vacuuming out.  Then
use some compressed air to get the fine dust out, but be careful
with compressed air on stuff like closely spaced load caps. Back the
pressure down. 

##   Eimac  tubes will  hi  pot test to  quadruple their max  anode ratings.   

Jim   VE7RF

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