On Aug 19, 4:11*am, Claude Frantz wrote:
Do you known about good articles (or books) about the design of
frequency multiplicator stages using tubes ?

I want to learn about choosing the operation point and the optimal load,
in order to get a good efficiency and a good output power while
reminding in the allowed limits.

Thanks a lot !

Clarke and Hess, "Communications Circuits Analysis and Design", is a
good book about operating points and goes into the math of figuring
out what harmonics are produced at an operating point and drive. They
also have a very good analysis of mixers. The math isn't heavyweight
but is definitely college-level requiring application of calculus and
it doesn't hurt to understand Laplace transforms either.

Today you'd probably do a SPICE simulation instead of the Taylor
series expansions that Clarke and Hess go through, but it's still very
worthwhile to understand what operating point parameters do in terms
of harmonics and the book gives insight that simply running
simulations won't give you.

In the ham cookbook sense, it is more common to copy a circuit out of
a handbook, build it and crank up the input power until you either get
the efficiency you expect, or you add another stage to get the power
you need. Both the ARRL handbook and Experimental Methods in RF Design
go into the sorts of efficiencies expected from different designs.

Most tube multipliers are simply operated in deep class C, with more
saturation than might be done for an efficient RF amp.

Tim N3QE