[Boatanchors] Why Are Tube AVC and DET Diodes Always Bad?

[Richard Knoppow]

----- Original Message ----- 
From: "David Stinson" <arc5 at ix.netcom.com>
To: <boatanchors at theporch.com>; 
<boatanchors at mailman.qth.net>
Sent: Sunday, December 23, 2012 7:33 AM
Subject: [Boatanchors] Why Are Tube AVC and DET Diodes 
Always Bad?


> Ever notice when you test the tubes from a rig,
> the Detector / AVC diodes in any used tube are nearly 
> always bad?  Is this because of the relatively
> small area of cathode dedicated to them, or is there 
> something
> in the design of tube-type detectors/AVC circuits that is
> hard on these elements?
>
> Has someone devised simple, non-destructive ways
> to bypass bad tube detector diodes and do these functions 
> with, say, a silicon signal diode, until one can get a NOS 
> tube?
>
> Please- I'm not at all interested in building a 
> "Multi-dimenstional Time-defused Quadralateraly
> Galactic Pi-R-round Cornbread-R-Square Phase-Potentulated 
> Product Mega-Demod"
> to do the job of simple diode detector.
> I just want to detect an AM signal, not create anti-matter 
> ;-)
>
> Thanks,
> D.S.
>
    If you mean 6H6 or 6AL5 tubes they measure weaker than 
rectifier tubes. Many tube testers have a separate scale 
marking for them.
    You could probably replace any of these diodes with 
Schotkey diodes. The performance should not suffer and you 
would never have to replace them.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com