FWIW
The G2DAF design was featured in the 4th edition (1968) of the RSGB
Handbook, did not appear in 5th of 1976 which showed a 2x813 gg job.
Suggests the editors thought gg better practice.
Nevertheless G2DAF with 2x813 does seem highly reproducible, having been
featured on the cover of RSGB Radio Communication magazine just a few years
back, and is mentioned in that mag from time to time where users universally
speak to its tractibility and good performance.
I would assume that hundreds, if not thousands of 2x813 G2DAFs have been
built.
There are still a few "ZL linears" in use down here and they sound
excellent: No fur around the edges and natural speech quality, which is the
object of the exercise, after all.
Neither of these might be the soundest designs, but they certainly can be
made to work well.
This is not intended to score off Rich or Tom, just setting the record
straight.
I have a 4-1000 or two in my collection, maybe next year try one in passive
grid AB something.
Have seen Rich's design for passive grid tetrode which looks a good way to
go.
Would appreciate any reports or comments on 4-1000 grid driven, especially
plate circuit design.
I am new on this reflector. While searching the archive a while back I
discovered data on 4-1000 using a tap to the plate tuning C to give a
partial L network to improve efficiency on 10m, but have lost the source.
Any help on this point much appreciated.
73
Baz ZL1DD
end
Barry Kirkwood PhD ZL1DD
Signal Hill
66 Cory Road
Palm Beach
Waiheke Island 1240
NEW ZEALAND
www.waiheke.co.nz/signal.htm
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