Hi Ian...
Just got back from Friedrichshafen & tooling around E. & W. Europe for a
few extra days and am catching up on mail at ETO.
Of course I agree emphatically that class of amplifier operation (biasing &
resultant conduction angle) and circuit configuration (what's grounded and
what's driven?) are fundamentally independent issues.
My involvement with "The Handbook" amps chapter was the 1995 edition only,
and I think (hope!) that the point was clearly made. But my only copy of
the book is 100 miles away at W0ID and I am anxious to check it upon
getting back up there this weekend!
If I failed to make that important distinction clear I'll be seriously
embarrassed. However, for now I'm hopeful and optimistic that a close
review of the relevant 1995 chapter (15?) will make sackcloth and ashes
unnecessary... this time, anyway.
73, Dick
-----Original Message-----
From: Ian White, G3SEK [SMTP:G3SEK@ifwtech.demon.co.uk]
Sent: Sunday, July 05, 1998 3:09 AM
To: amps@contesting.com
Subject: Re: [AMPS] Why class B??
John / NS1Z wrote:
>At 01:45 PM 7/4/98 -0700, Lane C. Zeitler wrote:
>>
>>Looking at my old Heathkit HA-10 Warrior I see that the designers set it
up
>>to be biased for Class B operation.
>>
>>What are the pros and cons of running class B vice g.g.??
>>
>Hmmmm???? I didn't know physical layout and biasing were related, what
have
>I missed?
>
Maybe the tube data tables in the ARRL Handbook. They use "GG" to mean
"grid and screen both connected to ground", which is presumably what
Lane was asking about.
This abbreviation adds to the confusion that already existed between RF
grounding and the class of operation - two subjects that are literally
un-connected. The ARRL Handbook ought to explain this in the 'RF Power
Amplifiers' chapter... Dick?
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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Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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