Picking up one of Rich's points:
>? As I recall, during the grate parasitics debate you stated that you
>were able to make an AL-80 oscillate at c. 155MHz.
>. Dick Erhorn claims that no Alpha has never sustained a
>parasitic-oscillation -- even though he has reportedly seen plenty of
>gold-sputtered tubes.
Here's part of a message sent to me some months ago, by someone who reads
these debates but chooses not to take part publicly -
>>I did a number of commercial amplifier designs in broadcasting and MRI
>>(including many years of experience with YC-156 at 20kW pulse) and saw
>>lots of parasitics. But never once did I see a parasitic cause damage.
>>We even once ran a test amplifier under load with a parasitic singing
>>along for several weeks. It was a pair of 8877s in parallel, operating
>>freq was 88MHz, and the parasitic was 220MHz. We needed to test the
>>ruggedness of the amp, but we couldn't tame the parasitic at the time we
>>were scheduled to start the "abuse test", so we just went into the test
>>with one prototype and worked on the parasitic issue on the other
>>prototype. No boiled off gold, etc.
(Quoted with permission, of course. The original author is not anybody
whose name I've ever seen mentioned in debate.)
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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