On Fri, 21 Dec 2018, Paul wrote:

looking for a single source supplier for tayloe switching mixer , like
fst switches, lvds, lt opamps, 74ac series etc

I don't think you can ever find a single source.

There's "Dans Small Parts" and he caters to hams, so hsi selection is
limited, and I think he's buying surplus parts, but it's sculpted towards
the ham. So you can get op-amps, but not many types, but you can get
toroids and some crystals and some key RF ICs. Sadly, he stopped selling
to anywhere but the US so I haven't paid a lot of attention in recent
year5s, but I think there's no minimum, and shipping is cheap or
diesappears if you buy enough. You won't get exotic new ICs there but for
a lot of radio parts, it is useful.

Digikey started out selling a keyer to the ham market, then added some
parts, and nowadays is a major distributor. So they probably carry most
parts, but might be lacking in some radio parts. Dan's wills ell you
variable capacitors, what he can get, but if Digikey has them, they will
be expensive. There are others like Mouser that probably covers
everything, that's a shift too. WHen I was a kid, exotic ICs would come
from distributors that carried select lines of companies, and often did
not welcome hobbyists, especially if they were buying a small order. Now
there are these "new" (because they didn't exist when I was a kid fifty
years ago) companies that handle everything, and seem to welcome small
orders as much as large orders.

Michael