The NE602 part (and it's 'kin) is usually used in RF circuits
but it includes (in part) a 'Gilbert Cell Multiplier' which
is (over SOME range of inputs) an analog multiplier with
fairly good specs (and cheap, since NE602s are ~$2.00).
I think this can be used for several of the problems that have
recently occured on this list. ==>... back on track.
I would like to get some description of a Gilbert Cell circuit
so I can better understand it. Maybe "SPICE" it up.
And if it does what I think it does, then I will post some 'tricks'
to this list <the "reward">. I don't find ref. in obvious places
but I'm a fairly 'green' web-ferret so far.

Thanks:  <Probably should reply to ME ONLY rmmartin@serv.net>