[Amps] TV sweep tubes and 6146s

[Tom Bowman]

What is the reason amplifiers never seem to be designed using  four 
6146s instead of TV sweep tubes like for example, four 6KD6s?
I must be missing something obvious here.

I'm asking because I'm thinking of building a 400W or so PEP amplifier 
for 75 and 40 meters.

Keeping cost really low is one of my goals here and I have several good 
6146s in the junk box.


73,

Tom, WA3REY