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[Amps] Clipperton L soft

Subject: [Amps] Clipperton L soft
From: Kelly Taylor <>
Date: Thu, 20 Jul 2017 16:58:33 -0500
List-post: <>
Hi all,

Just trying to diagnose a weak Clip L. 

Here's what I see;
On CW, the Vp meter shows 700 volts. 
The transformer, when isolated, reads five ohms to the low-power tap and eight 
ohms across the entire secondary 
The filter caps each start out showing short then gradually charge to then read 
the 100k of the parallel resistor. 
The diodes read low resistance forward and out of range reverse.
The "fuses," two delicate resistors in series with the plate choke, and the 
choke itself, read very low in resistance
Thinking I shouldn't trust the internal meter, but wary of servicing it live, I 
checked the values of the three resistors in series acting as a divider for the 
meter (each is off by 30%). The meter shunt resistor, again, isolated, reads 
within one per cent of spec. 

I don't want to drop $300 on tubes only to find nothing's changed, and don't 
want to drop $100 on a Harbach kit only to find it was just the tubes all 

Someone's been inside here before me; the electrolytics are not factory and 
there's some not-entirely-professional soldering, but the connections all seem 
fine electrically. 

Is the off-spec condition of the meter dividing network just a diversion from 
bad tubes?

There's no evidence of any component having let out its smoke. 

73, kelly, ve4xt 

Sent from my iPhone
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