[AMPS] TL-922 Filament Transformer Protection

[Ian White, G3SEK]

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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