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[AMPS] Re: 30L1 Grid Circuit

To: <amps@contesting.com>
Subject: [AMPS] Re: 30L1 Grid Circuit
From: measures@vc.net (Rich Measures)
Date: Sun, 18 May 97 23:01:58 -0700
>On Sat, 17 May 97 20:21:24 -0700, Rich Measures <measures@vc.net>
>wrote:
><snip>
>
>>The reason why Collins Radio Co. did not neutralize the 30L-1 is because 
>>there is no way to neutralize a single ended g-g amplifier....snip...

>Are you sure there's no way to neutralize a single ended GG amp?  

Yes.  GG amps are already neutralized at the operating frequency.  Is it 
possible to put a bucket of water in a bucket that is already filled with 
water? 
  Why is Ameritron-MFJ the only g-g amp. mfg. on the planet that claims 
to "neutralize"?   Ask Warren Bruene, W5OLY,  about the Rauchian 
"neutralization" circuit.  

>MyAL-1200 has what the manual calls a neutralizing circuit.  It's a
>small toroid transformer which feeds some of the anode energy back to
>the cathode with 180 degree phase reversal.  

I find no such circuit in Eimac's  *Care and Feeding.........*.  It does 
not seem very likely to me that a person who rejects AC circuit analysis 
would be capable of better RF-engineering than Eimac.  

>There is a neutralizing
>"tab" (capacitor) adjacent to the anode, and the manual says "In the
>event the tab becomes displaced, proper neutralization will occur when
>the maximum output power and grid current and minimum plate current
>appear concurrently."
>
>If that isn't neutralizing, what is it?

 A delusion?  'Do'  claimed there was a ufo parked behind the comet.  B. 
Stanley Pons and Martin Fleischmann claimed that 'Cold Fusion' worked.  
 In my opinion, the AL-1200 can not oscillate at the fundamental 
frequency---but it can occasionally oscillate at the anode circuit's VHF 
resonance. 
  Mr. Rauch told me that it is impossible for an amplifier he designed to 
have a VHF parasitic oscillation.  I asked him why not.  His answer 
"Because Tom Rauch designed them."  
 The zenith of Mr. Rauch's VHF-stability confidence level was apparently 
the AL-1500.  It alone uses no VHF suppressor whatsoever in the 8877's 
anode circuit.  I have spoken with a number of AL-1500 owners who had 
more than one tube suddenly fail during the 12-month warranty period.  
This subject was brought up at least eight times during the vhf 
parasitics debate, but to no avail.  Mr. Rauch stonewalled.  Do real 
experts stonewall?  
Rich---


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


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