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[AMPS] Tube Input Impedence

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Subject: [AMPS] Tube Input Impedence
From: watson@epiloglaser.com (George K. Watson)
Date: Wed, 22 Apr 1998 10:08:44 -0600
I have searched the extent literature a bit and have not found the answer
to the following question:
What are the componenents that contribute to tube input impedence
for a directly heated cathode, GG configured triode?

I have a recently obtained a "way off broadway" tube, the GS31B from
a friend in the EU and am interested in building a 6m amplifier with it.
The tube was manufactured in the old Soviet Union for use in spamming
transmitters.
These are the characteristics that I have:

Coaxial construction, directly heated cathode
Heater is AC 12-13,2 V / 3,1-3,7 A; Typical is 12,6 V / 3,4 A 
Plate Dissipation 1000 W 
Plate Voltage up 3000 V 
Plate current 1000 mA (max 1,4 A/30sec) 
Plate Temperature 200 degrees Celsius max! 
Grid Temperature 120 degrees Celsius 
Cathode Temperature 120 degrees Celsius 
Required Air flow 100 l/min 
Grid Voltage min -200 max 0 V 
Grid current 50 mA (max 100 mA) 
Grid Dissipation 22W
FQ max 1000 MHz
C (g-p) 3,8-5,2 pF 
C (g-c) 19-24 pF 
C (c-p) 0,12 pF

Also, how would I determine an appropriate bias for the tube?

This is my first vacuum tube RF amplifier and I have a feeling it will
be a tough project, however, the tube was fairly inexpensive and if
I screw something up badly, I will not have lost much.

BTW my HV PS is 2.2kv @ 1A

Thanks in advance,
George
K0IW

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