From: Peter Chadwick <Peter_Chadwick@mitel.com>
Subject: RE: [AMPS] Amp using 833A
>
> Rich says:
>
> >Medium Mu triodes draw little anode current unless the grid is driven way
> > positive- and that means distortion.
>
>
> This is not necessarily so. Class AB2 or Class B2 operation with grid
> current in grounded cathode requies a well regulated bias supply, and a
> well regulated drive, but it does NOT automatically mean high distortion.
> Pappenfus in fact says that AB2 can result in lower IMD than AB1.
I think this goes back to arguments in the past Peter, where Rich
felt that:
Any positive grid to cathode potential = unacceptable distortion
That equation isn't true in many if not most cases. The worse thing
about the 833 will be stability and the fact that drive power in GG
would be too high. If it provides acceptable distortion in AM BC
service as a class B or ABx modulator, it is likely to provide
acceptable distortion performance as a linear amplifier if other
issues can be resolved.
73, Tom W8JI
w8ji@contesting.com
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|