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[AMPS] Setting the record straight--Dick Ehrhorn

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Subject: [AMPS] Setting the record straight--Dick Ehrhorn
From: (2)
Date: Wed, 18 Jul 2001 02:39:50 -0700
>AMPS Reflector--
>Rich Measures said on July 2, 2001:
>"Low Rp parasitic oscillation suppressors apparently work. The Alpha
>86 & 87 does not use such suppressors. Around 40% of the 80-series Alpha
>owners I surveyed reported sudden failures that required factory repair.
>When Alpha founder Mr. Dick Ehrhorn was active on AMPS, he said that he
>had seen hundreds of tubes with gold-sputtering damage."
/\   I was wrong.  I checked my notes and the quantity was 150, not 
hundreds.  However, I have autopsied enough kaput gold-sputtered 8874s 
and 8877s that were removed from ETO/Alpha amplifiers to know that it can 
happen -- but not as much as in amplifiers that do not use a parasitic 
suppressor, such as in the SB-230 and AL-1500.  A photograph of one 
autopsied 8874 with gold-sputtering is shown in "Parasitics Revisited" 
(September-October, 1990 *QST*).  This tube was one of three that were 
removed and tested from an Alpha 78.  Two of the tubes had this problem.  
>This didn't sound like a correct attribution to me so I forwarded
>the quote to Dick Ehrhorn to confirm if this is what he had said
>or what he believes.  And this is Dick's reply:
>"Measures is simply unbelievable & evidently clean out of his gourd now. 
>We had long exchanges on the amps reflector concerning tube failures. I made 
>100% explicit that I had NEVER seen, or been made aware of by a credible
>source (i.e., Eimac or our lab), of even one 3CX800A7 (or any other tube
>type) failure which was attributable to parasitic oscillations in any ALPHA 
/\  Eimac's Warranty Dept. does not specifically test for gold-sputtering 
leakage.  If any leakage is detected, the tube is replaced and the dud is 
tossed into a scrap bucket.

>I just wanted to clear up this misinformation and misrepresentation
>of Dick's position on the issue.
>John W0UN
/\  John - what kind of HF amplifier do you use?


-  R. L. Measures, 805.386.3734,AG6K,  

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