[Amps] Bias Zener Diodes In Parallel ?

[2]

>Adjustable yes, but you don't have to
>change taps, just apply current through
>the string and it's voltage drop wanders
>all over the place.  

Fwd drop varies little between 0.2A and 1A in a Si junction.
 Henry Radio Co. amplifiers have used fwd-biased diodes for years.  I 
have used fwd biased diodes for over a decade in a TL-922 and a SB-220.  
The ZSAC is virtually constant and I can set it if I change tubes. 

>For voltage
>stability this is the worst way to
>provide bias.  

So a resistor in the cathode would not be worse?

>TL-431, adjustable and
>rock solid voltage.
>Paul...

>> The problem with a 50w zener
>> is that its Vz is not adjustable.  A
>> fwd-biased Si diode string
>> can be adjusted by changing taps.

-  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, 
www.vcnet.com/measures.  
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