[Amps] 8122 x 12

[G3rzp at aol.com]

In a message dated 29/12/2004 10:33:54 GMT Standard Time, sm0aom at telia.com  
writes:

When I  think about it, the H-1000 was probably only rated to 25  MHz....
There were variants. When used as a drive for the H1200 30kW tx, they were  4 
- 27MHz: stand alone as the HS113 (which I believe was the original type  
number) they were 4 - 27MHz.
 
They were one reason that 4CX250Bs were fairly readily available to hams in  
Chelmsford - although few people bothered! 
 
I've got some papers from an IEE Conference on HF back in 63, where they  
were described. There'a also a paper from STC about a 60kW tx: the variable  
inductor in the L match used silver plated copper pipe with air blown down the  
inside to cool it, and a wiper of specially made silver loaded graphite. Rich's  
advice about providing air cooling for tank coils has some good  
precedents....
 
I don't think there's anybody left making fair sized HF tx's in the UK -  
well, maybe some of the UK subscribers to this reflector!
 
73
 
Peter G3RZP