Re: Building a junk box.

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From: John F. Woods (jfw@ksr.com)
Date: Wed Jan 05 1994 - 10:44:39 EST


> One of the QRP books I was reading suggested stocking up on bread and
> butter parts at hamfests but what parts are bread and butter?
> Are their particular values of caps and resisters I should be looking for
> or just a good bulk deal? How much should I be looking to spend?

If you're in a hurry, DigiKey has bulk resistor assortments (which I used to
start my junk box); their RS-125 is a set of 5 each of the 73 5% standard
resistors (1/4W) between 1.0 and 1.0M, for $14.95; their RS-225 is the 72
5% standard values from 1.1 to 910K, $14.95. They also have equivalent 1/2W
assortments (RS-150/250, $16.95). These are all carbon film. Probably
you can do much better than that at hamfests (4c per resistor), but at least
you'll know where they came from :-). That approach also has the advantage of
making sure that you *do* have any value that gets called out in a schematic,
whereas hamfest/mail order packets have a tendancy to be either "whatever
random resistors were overstocked somewhere" or "the ones that crop up most
often in the schematics I've built so far". Of course, once you start out with
5 of everything, you'll find that you *do* want an absolutely full drawer of
1K resistors but may never actually get around to using those 1.2 ohm resistors
...
Mouser also has a carbon composition assortment you'd probably want (much less
complete, but has the really popular values, well most of them).

DigiKey also has capacitor assortments, but capacitors are somewhat trickier
to stock up on -- you need *so* many different *types*, and capacitor
manufacturers are somewhat lackadaisical about standard values, especially
mica capacitors. I got a few of DigiKey's assortments (popular values, not
complete sets) and have mostly relied on random purchases to fill up my junk
box.

To stock up on toroid cores, I took out W1FB's QRP Notebook and QRP Handbook,
figured out the most popular cores, and got a bunch of those. Unfortunately,
my junkbox is at home so I can't just come up with the answer I found; as I
recall, though, I think it's mostly T50 and T68 in #2 and #6 material (T30 as
well, I think), and three sizes of two types of ferrite that I can't recall.
(I've also got a whole bunch of T44-7 cores due to a repeated mixup by Amidon.)

A *long* time ago I used to gut TVs &c for parts, but I now lack the patience
(and modern TVs lack the recyclable parts :-).


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