On Sun, 14 Mar 2004 21:27:19 +0000, Paul Burridge
posted this:

On Sun, 14 Mar 2004 19:51:50 GMT, James Meyer
wrote:

I'm still working on an LTspice version of a varactor multiplier using
the base-emitter junction of a class C amp as the varactor. Basically using an
"idler" tank or tanks to augment the fifth harmonic.

The other idea is to make a doubler and a trippler fed from the
fundamental and then feed them into a mixer to get the fifth. If the doubler
and trippler are active (class C) stages, you should get as many db out at the
higher frequency as you put in at the fundamental. The mixer can have gain too.
Three transistors, three tuned circuits, and Bob's yer uncle.

Jim, please remember the fundamental has to be in the order of
~3.5Mhz.

3.5 MHz... 3.5 GHz 3.5 uHz... makes no difference. The laws of physics
scale nicely for most electronic circuits. Although some ICs are getting
features small enough that the electrons have to line up single file. 8-)

Jim