[Amps] 8122 x 12

[G3rzp at aol.com]

In a message dated 29/12/2004 08:45:18 GMT Standard Time, sm0aom at telia.com  
writes:

About 30  years ago, you could buy such an amplifier from Marconi, the H-1000.
It  used 12 4CX250B's in a distributed wide-band amplifier configuration and  
provided
1 kW CW or PEP with 100 mW drive between 1.5 and 30 MHz.  



When I worked on them at Marconi, going above about 28MHz resulted in  
smoke!!! There was an unfortunate resonance in the 10 metre band which was  a bit of 
a pity.......
One downside of the distributed amplifer is that half the RF is wasted. The  
signal into the anode lines goes to the load at one end, but the other end 
needs  a termination resistor.
 
Distributed amps were used a lot in 'scopes and rx multicouplers. There's a  
good description in Millan and Taub's Pulse and Digital Circuits. More 
recently,  they've been used in wideband microwave amps using GaAsFETS,
 
73
Peter G3RZP