[Amps] Anode Impedance of 4-400A

[Phil Clements]

The load impedance of any tube or group of tubes is anode voltage under load
divided by total anode current times 1.8. It matters not what the type or
brand of the tube(s) are. A single 8877 amp that has 4000 volts on the anode
and an anode current of 1 amp will have a plate load impedance of 2222 ohms.

(((73)))
Phil, K5PC


 Subject: [Amps] Anode Impedance of 4-400A
> 
> Does anyone know the 'rough' load impedance of a pair of 4-400A's with
> 3500V on the anode?
> 
> In some of EIMAC literature (W6SAI AS-1 Publication), there are tables,
> which list it as 5000 Ohms.  Is this for one tube, or two?
> 
> The 1982 ARRL Handbook contains a design with a pair.  The PI network
> values listed there, equate to a load of 5000 Ohms, with a Q of about 12.
> 
> 
> I am just trying to cross a few items off of my list.
> If someone can contact me off list, I would appreciate it.
> 
> Thanks
> Eric Thielking