[Amps] FW: 4CX5000A in common grid circuit

[Markku Oksanen]

All

I found this 
http://www.cpii.com/docs/related/22/C&F4Web.pdfand it looks like chapter 4 of Pappenfus' if I understand it correctly.
Against current "wisdom" this states (page 104)  that a properly designed tetrode in GG will give a gain of 20 to 50 while triodes tend to remain below, at the level of 7 to 20, 20 seems to be a sign of a good design these days with modern high muu tubes.  
Can anybody help with this???  Is this correct?  I have never before heard that tetrodes in GG can give such high gain. Are there specific requirements for the tube??
I still didn't find direct gain formula but managed to calculate some estimates based on voltage gain and impedance levels.  What the GG muu value to use with a tetrode is, I don't quite know.
Looks like it makes good sense to try a GG design first with the some forethought in case grid drive becomes a necessary change later. Gain of over 20 is plenty good enough.
Thanks for the hint / help!


Markku WW1C

> Date: Thu, 2 May 2013 16:28:16 -0600
> From: jtml at losalamos.com
> To: amps at contesting.com
> Subject: [Amps] 4CX5000A in common grid  circuit
> 
> 4CX5000A is in the Collins design in the 1964 Ed of Pappenfus' SSB Principles. It will give you a reference point. If you can find the NAB handbook from the 1986 era, I wrote the section in FM transmitters, comparing a 4Cx3500A in to and gg circuits, class c though, at 100 MHz. Its a similar but better tetrode. If you put voltage on the screen you can get fairly high gain, like 12 db I think. Memory may be fading here.
> 
> Sent from on the road...
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