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[AMPS] splatter etc

To: <amps@contesting.com>
Subject: [AMPS] splatter etc
From: measures@vc.net (Rich Measures)
Date: Thu, 12 Jun 97 06:11:17 -0700
.....
>Rich asks why Eimac, Svetlana etc don't suggest regulated supplies.
>
>My guess, ..... ........... ............... ......... ............... 
............... is that
>as regulated  supplies cost money, you make sure that the data sheets
>offer the CHEAPEST possible application - thus no regulation! 

The additional parts cost of regulating an 8171 grid bias V supply is 
roughly $18 with Mr. Rauch's bias V regulator circuit---which, for Class 
AB2, makes $ense.  

So why do 100% of the power grid tube manufacturers recommend regulated 
screen supplies?  It IS possible to achieve okay IMD without a regulated 
screen supply.  The Henry 4k-2 did it.  

Some questions: 
-1- If the electric-mains potential decreased 5%  in a Class AB1 tetrode 
amplifier (with an unregulated anode supply), would the ZSAC (zero sig. 
anode current):
A.  Decrease?
B.  Increase?
C.  Remain the same?
-2- If the grid bias V decreased 5%  in a Class AB1 tetrode amplifier 
would the ZSAC (zero sig. anode current), 
A.  Increase?  
B.  Decrease?
C.  Remain the same?
 IMO, the answers are -1-: A and -2-: A.  In other words, the decrease in 
ZSAC due to less anode V would be somewhat cancelled by the concurrent 
decrease in grid potential.  However, if the grid bias supply were 
regulated, would this cancellation take place?    

>So do any of you have ideas for a session at Dayton 98 on Amplifiers? 
  I took a Physics of Electricity Class with 250 students.  It was 
somewhat unwieldy.  Later, when I was teaching, I found that a group of 
about12 is semi-ideal.  However, I learned that one person with an agenda 
is poison no matter what the class size. . For instance, it would be 
difficult to deal with one person in the audience that profoundly 
disagrees with accepted circuit-analysis methodology.  
>If
>some of you can volunteer to do say 20 to 30 minute sessions, 
IMO, 20 to 30 minute speeches are dead fishes.  The malpractice reminds 
me of the old lock-to-talk, put the hammer down, AM diatribe days---i.e., 
B-O-R-I-N-G..  Dialogue is what works.  //   Listening to Congress' 
speeches is a sure cure for insomnia.  Listening to the House of Commons' 
banter is a wake up call.  
Rich---

R. L. Measures, 805-386-3734, AG6K   


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