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Re: [TenTec] Low power output on Argonaut V

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] Low power output on Argonaut V
From: Bob Towers <mm0rkt@beeb.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 01 Aug 2007 10:03:45 +0100
List-post: <mailto:tentec@contesting.com>
Stuart Rohre wrote:
> You an check for gross shorts or opens with the diode test function on the 
> finals too.  I would imagine they might fail short rather than open.  Do 
> they get hot, even with low power output?  That would be a short.  Of 
> course, if open, they might act as a capacitor and pass some driver power to 
> the antenna connection.

I think the leads are accessible without taking the board out. Maybe a 
bit of poking around, but definitely worth a try.
> Just be sure any meter you use has low current if acting as a ohm meter for 
> testing.  And voltage.  Modern DMM's are probably safe for finals and 
> drivers.

Yes, I only use a DMM these days.
> Might be reluctant to use an old AVO meter VOM to test in today's transistor 
> circuits.

Years ago I had an ancient AVO but it probably went in a clear out. 
They're worth a bit nowadays...
> A surely safe test for a final, is to check the source or emitter resistor 
> DC voltage drop.  If there is a voltage drop, it is handling some current. 
> If no voltage at the resistor high side, the device is open.
> 73,
> -Stuart
> K5KVH 

Just a thought.. When diodes blow, I presume they go open circuit. Or do 
they? Is it possible just to destroy the semiconducting properties and 
leave a linear resistor?



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