On Mon, 28 Nov 2011, K7ITM wrote:


With regard to the parts that places like DigiKey and Mouser and other
authorized distributors stock: I seriously doubt that any homebrew
projects are going to have much effect on what they stock. It's the
parts that are bought for production, by the reel, or at least by
hundreds for some of the more exotic parts, that get their attention.
If you see them with a stock of 10,000 or more of something, you can
bet they didn't get them because they got some orders from random
homebrewers.

But in the old days, it did matter. When there were local parts stores,
and small mail order places. Why were there all those 2N706s specified
for a long time, until 2N2222s became common? People still specify "1N34"
when what they are really specifying is a germanium small signal diode,
much of the time people didn't really care what the part number was, I
seem to recall ads just saying "germanium diodes".

Even today, there is a relatively small handful of components specified,
albeit a more recent selection.

I have no idea what came first. Did whoever used the 2N706 first look
through databooks and find something "right" and then buy some, or did it
start with going to the parts store and finding what was available? But
as I said, once the parts were in the construction articles, those were
the parts you'd see in the ads, back when the ads were the full line of
what was carried, or a good part of it. Those places didn't carry a full
line, they carried what would sell, so they'd carry what was being
specified in the construction articles.

If you look at the UK or European magazines, you'd see the same small
subset of parts being used, albeit a different set of specific devices.

It still holds true with a place like Dan's Small Parts. He has the
familiar FETs, a dozen or so types of small signal bipolar transistors,
unless he ends up with some overstock of some "exotic" device that's more
or less like the common devices. He doesn't carry endless ICs, so he does
pick to match what is commonly used. It's not a good place for exotic
components or a wide range of components, but for non-digital projects
it's a better place than many, since they carry radio type components like
variable capacitors, so it often avoids orders to multiple places.


The flip side is that in keeping to a small selection of common parts, one
can keep those in stock at home, and be able to throw together a lot of
things on whim. Who doesn't have some 2N3055s and 2N2222s and 2N3906s and
MPF102s?

It was a different era. The hobby suppliers worked as middlemen between
the distributors and the hobbyists. The distributors often didnt' want to
deal with small orders. So new places rose up that would buy in bulk and
sell in small quantities to hobbyists. Since they were small companies in
themselves, they couldn't afford to buy large quantities of lots of parts,
so they picked the popular ones.

I remember about 1974 wanting some "new" ICs, the MC4044P and the MC1648
and the old style parts stores didn't carry things like that yet (and
wouldn't, they'd start disappearing in a few years), so the only way was
to go through a complicated procedure to get them from the local Hamilton
Avnet distributor. And it seemed at the time that they weren't the
general distributors such as Mouser, if you needed some other company's
parts that they weren't a distributor for, you'd have to go to some other
distributor that did carry the line. You'd look in the phone book and
someone would be a distributor for Motorola, another for RCA and so on.

When Active Electronics opened up, it was a big deal because they were
carrying multiple lines, and were sort of willing to deal with the
hobbyist (initially we'd fill out a form, then it would get sent back to
the warehouse to be filled, but slowly they prepackaged components and it
was self serve for the common ones). It was sort of like the old parts
stores, except carrying more leading edge components. But even when a
wider variety of parts was available from places like that, we'd all stick
to more or less the same handful of parts.

Digikey is an example of all this. Started out selling a keyer kit, they
started selling parts and if I'm remembering properly, there was a period
when they listed all or most of their stock in their magazine ads. Then
they grew and grew more, going from a small company catering to hobbyists
with a select number of devices, to being a major source of parts from a
wide range of companies, and really dealing with selling to other
companies, but still having some sort of reasonable policy for the small
time buyer.

Michael VE2BVW