Re: cheap way to test "doorknob" capacitors? (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 11 Nov 2004 09:06:49 +1300
From: Malcolm Watts <m.j.watts@xxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: cheap way to test "doorknob" capacitors? (fwd)

On 8 Nov 2004, at 15:05, High Voltage list wrote:

> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Mon, 8 Nov 2004 00:08:42 -0500
> From: Jack Vandam <snotoir7674g@xxxxxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: cheap way to test "doorknob" capacitors?
> 
> I have just come across an assortment of used doorknob capacitors. 
> Since I don't know whether or not they work, I would like to test
> them.  What would be a simple way of doing this?

To check their capacitances you could marry them individually with a 
known inductance and check the resonant frequency of the resulting 
tank. In my experience, used doorknobs may well be down on 
capacitance if they've been thrashed as the metallization can't 
handle large currents.

Malcolm