Filter out the Subject with your E-mailer app., and the cramping will go
away.
>I agree with you Dale. Let's move on to something more interesting.
>
>Bert A.
>
>
>-----Original Message-----
>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
>Behalf Of dj2001@mn.rr.com
>Sent: Tuesday, March 04, 2003 8:51 AM
>To: amps@contesting.com
>Subject: Fwd: Re: [Amps] 8877s, ETO and the General Electric Contract
>
>
>
>This reminds me of a bloody barroom brawl. It's getting kind of ugly
>sorry to say and I'm not learning anything useful about amplifiers.
>
>Dale J.
>
>
>
>
>
>>Subject: Re: [Amps] 8877s, ETO and the General Electric Contract
To: <amps@contesting.com>
>>Date: Tue, 4 Mar 2003 07:47:55 -0800
>>From: rlm <2@vc.net>
>>To: "Tom Rauch" <w8ji@contesting.com>, " AMPS" <amps@contesting.com>
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>>
>>
>>>> I started to have this problem in 10th grade and the problem isn't
>going
>>>> away.
>>>
>>>The problem is rooted in false claims, poor technical advice, poor circuit
>>>behavior descriptions, and general misinformation. Unless the correct
>>>information gets out, the problem will continue. We should concentrate
>more
>>>on technical issues, and less on what we "imagine".
>>>
>>>> ** Interesting, Dave. I apparently assumed wrongly. My take on the
>>>> issue is that GE knew more about the 8877 failure problem in ETO
>>>> amplifiers than is assumed by some. GE's awareness of the VHF
>parasite
>>>> problem goes back to 1935, when GE engineer G. W. Fyler wrote about the
>>>> problem in "Parasites in Transmitters" in the Sept. issue of the IRE
>>>> Journal. // The first Eimac technical data sheet on the 8877 was
>>>> published in 1970. Eimac's W. B. Foote told me that the gold-migration
>>>> problem was discovered by the 8877 development team. Thus, they must
>>>> have known about the gold-migration phenomenon at least 16-years before
>>>> Foote told me about it in February of 1986.
>>>
>>>Neither the Foote letter nor GE said anything of the sort.
>>
>>I have no idea what GE said to Dick E.
>>The Eimac Letter:
>>=======================
>>"VARIAN ElMAC, 301 Industrial Way
>>San Carlos California 94070 1 U.S.A. / Tel. (415) 592-1221 TWX 910
>>376-4893
>>February 18, 1986
>>
>>Mr. Richard L. Measures
>>6455 La Cumbre Road
>>Somis, CA 93066
>>
>>Subject: 2 pcs returned 8875 S/N G8AD-241 and F8VD-428J, for evaluation.
>>Reference: Your letter dated 21 January 1986; EIMAC RPA #SC-2303.
>>
>>Dear Richard:
>>
>>Your letter about parasitics is quite interesting, and it appears your
>>two tubes have had the same trouble. The emission was poor on test, and
>>consequently other test results looked bad. The tube engineer then cut
>>them both open for an internal examination.
>>Both have been badly overheated internally, the apparent result of an
>>oscillation condition. The grid in these tubes is gold plated and if
>>overheated the gold vaporizes off, of course, and some of it inevitably
>>lands on the oxide cathode, and that poisons emission.
>>
>>Though your tubes are quite old (mid-1978 vintage) we will replace them
>>in the interest of good user relations. We will scrap the two you sent in
>>here, as we have to be sure they are out of circulation when we replace.
>>Good luck in your continued operation.
>>
>>Sincerely, WILLIS B. FOOTE, Chief Specifications Engineer, Power Grid
>>Division."
>>------------------------------
>>** I take this letter to say that gold apparently evaporates during an
>>oscillation condition.
>>>
>>>Back in the 30's, tubes had long thin leads.
>>
>>** Some still do. However, low L leads only move the problem higher
>>because the ability to oscillate also moves up.
>>
>>>Nearly every amplifier was
>>>operating at the upper frequency limit of construction, components, and
>>>wiring. Becuase the amplifiers were operated near the limits, having very
>>>poor tubes, wiring, and components by today's standards there was no
>>>effective way to stabilize the PA's.
>>>
>>** G.W. Fyler (and F. E. Handy) came up with a simple idea that proved to
>>be fairly handy -- i.e., "the plate or grid parasitic circuits should be
>>damped with resistance". (GWF. Sept.1935)
>>
>>>It was impossible, in the 30's, to get enough transfer from current in
>>>inductance to the dissipative resistance as the frequency of oscillation
>is
>>>approached because the operating frequency and instability frequency much
>>>closer than they are with devices even from the 40's and 50's.
>>>
>>** Say what ?
>>
>>>Because of poor layouts and poor components amplifers had to be
>gain-reduced
>>>even near the operating frequency.
>>>Only a fool would think that has some universal meaning in modern systems.
>>>It would be like insisting jet engines use gravity-fed fuel systems, which
>>>worked so well in the early days of aviation. Vastly different systems
>>>almost always require different solutions, when looking for the optimum.
>>>
>>>> The story I got was that GE was concerned with the tube failure rate.
>>>
>>>The story I heard was you applied for a job at a major amplifier
>>>manufacturer, and your application was rejected.
>>
>>** I was a metrologist who also taught electronics. Amplifier building
>>was just a hobby that started when I was 15.
>>
>>>I was told since then, you
>>>have had a grudge against ETO and all manufacturers.
>>>
>>** I didn't know anyone who got cremated in a Ford Pinto or Crown
>>Victoria rear-ender.
>>
>>>> plant. When I mentioned the 150 figure on AMPS a couple of years
>later,
>>>> Dick said I was going insane.
>>>
>>>I know you say some things here that you attribute to me that I never
>said.
>>
>>** Like the letter I received from a person who claimed to be Tom Rauch
>>which threatened to sue me and QST if my Rebuttal to the 9-94 QST was
>>ever published in QST? If this person was an impostor, his timing was
>>uncanny since his letter arrived about a 10-days after I mailed a copy of
>>my Rebuttal to the real Tom Rauch.
>>
>>>I always wonder how often you do that in "technical" discussions. Why not
>>>leave all the personal stuff about Dick
>>
>>** Dick E. played the Insane Card and I said so.
>>
>>>and everyone out, and stick to
>>>honest facts?
>>
>>** Like when the smoke began to clear at the end the Grate Parasitics
>>Debate, when your faithful groupies were suggesting that I was probably
>>boinking the teenage girl who was filling suppressor retro-fit kit orders
>>?
>>>
>>Cheers, Tom
>>
>>- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
>>www.vcnet.com/measures.
>>end
>>
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>
>_______________________________________________
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>
>
>_______________________________________________
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>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
end
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