[Amps] 3cx300a7 input impedance

[rees.a]

This is waht I have, hope it helps:


Characteristics
Plate Dissipation (Max.) 4,000 Watts 
Screen Dissipation (Max.) --- Watts 
Grid Dissipation (Max.) 225 Watts 
Frequency for Max. rating (CW) 110 MHz 
Amplification Factor 160 
Filament/Cathode Thoriated Tungsten 
Voltage7 .5 Volts 
Current 51.5 Amps 
Capacitance Grounded Cathode:
Input 38.0 pf
Output 0.6 pf
Feedthrough 24 pf
Capacitance Grounded Grid: 
Input 38.0 pf
Output 24.0 pf
Feedthrough 0.6 pf  


Cooling: Forced Air 
Base: Special, coaxial 
Air Socket --- 
Air Chimney --- 
Boiler --- 
Length 9.00 in; 228.60 mm 
Diameter 4.15 in; 105.50 mm 
Weight 6.2 lb; 2.8 kg 
 


----- Original Message Follows -----
From: Steve Thompson <g8gsq at ic24.net>
To: "john devoldere, ON4UN" <john.devoldere at telenet.be>
Cc: amps at contesting.com
Subject: Re: [Amps] 3cx300a7 input impedance
Date: Tue, 09 Aug 2005 14:10:24 +0100
> 
> 
> 
> john devoldere, ON4UN wrote:
> > Can anyone help me with the input impedance of the
> > 3cx3000a7 tube (used on HF). I require this value to
> build a proper Pi- filter input circuit. The datasheet I
> have gives values between 46 and 50 ohms for different 
> conditions from 4 to 4.8kV, 300-400W drive and 6-7 kW out.
> 
> Steve
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