[Collins] 572B in 30L-1

[Gerald]

On Mon, 2005-05-09 at 19:32 -0500, Jim Isbell, W5JAI wrote:
> What does converting a 30L-1 to 572Bs in the final do for or against it???

Probably leads to smoke, either the power supply or the output network
unless the 572B are run at 811 ratings. There was a lot of shoehorning
to get the parts into the 30L-1 case and there's not a large margin for
more power.

I'm sure some have run 572B and not noticed any smoke. 

I didn't find any official 572B data quickly. The ARRL handbooks I
checked don't show output C. Surely a tube with 2.66 the dissipation of
the 811 has enough bigger of a plate to raise the output C nearly as
much as the dissipation, that could make tuning 4 to 10 meters
difficult. I'm thinking the 572B is a bit taller than the 811 which
might make it a tight fit in the 30L-1.

A couple 572B would be a better match to the output network and power
supply than four.


-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer