I've pretty much decided on a single 4CX800A. The price seems to be
right. I think 200w of carrier might be an appropriate target. I run
AM mostly. My next step is to decide on a transformer for the
thing. Plan of attack for me is to find a manual on BAMA that uses one
tube and see what the transformer specs are. I'll try and do a paper
design and come up with the transformer specs that I would need. I
hope the two agree. I looked up an alpha design that uses two tubes
and found a Peter Dahl transformer for the thing was $425. Ouch!

If you have a particular amplifier in mind that uses just one of these
toobs then please say so. I need to get a flavor for the transformers
available. I will probably buy another Peter Dahl unit.


I Got my HX-50 up and running last night for the first time. Had to
replace the transformer and a recap and so forth. I am poking around
to see what I can get out of it powerwise. I got 30w on 75m cw no prob
into a dummy load. I guess when all is said and done I will put it on
my boss's spectrum analyzer and see what I got to drive a linear with.

I realize that this project could be more expensive than a commercial
unit, but I can get many of the parts for free from my boss. He is a
real good guy and gives me stuff all the time.

thanks for the help.

regards,
Bob
N9NEO

I looked up an alpha design that uses two tubes
and found a Peter Dahl transformer for the thing
was $425. Ouch!

The Peter Dahl prices are fair but not exactly cheap.

Your best bet is finding a junker linear and "inheriting" the
transformer/bandswitching/inductor/capacitor and maybe even the plate
choke (although most junkers probably have a burnt up choke and maybe
some burnt up bandswitching).

I've pretty much decided on a single 4CX800A.

I assume you mean an ex-soviet "GU74B"? You can find a lot of designs
around the net using that part number.

Tim.