Re: Building a junk box.

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From: Randy (randy@cyphyn.radnet.com)
Date: Wed Jan 05 1994 - 00:28:21 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?
> Thank's Rod
>
Oh my!
       Resistors, in bulk....caps, in bulk....values like .001 thru .1uf
of the disc type...50-100 volt rated... .047 (473) being a good universal
fit most everything value...

values like 4.7 pf thru 820 pf, disc, NPO is best, maybe some N750's etc
all being 100v thru 250volt would be best...

Electrolytics (or tantalums <---cost more) of the 1uf thru 1000uf sizes,
15vdc to 35vdc ones being best, while the 6 and 10vdc ones end up being
orphaned...not too many ckts run on such a low voltage!

and for resistors, 1/8 thru 1/4 watt, 100ohms thru 100k if not higher...

trim caps, trim pots, small tuning caps with usable length shafts and an easy
way to mount them...regular pots (WITH the nuts!)

Knobs---ones that fit the shafts of the above....and a hex key wrench to
fit the set screw of them!

Nuts, bolts star-washers spacers (metal and non metal)

PC boards single and double sided

Transistors like 2N3904 2N2222 or their generic subs....

Lots of various colour wire...LOTS of it!

plugs, sockets...but stay away from BNC...they wear out fast.
I use PL-259 and SO-234 or RCA the most.

===
A good source of yummy parts would be from a roasted TV or VCR...which now-
a days, costs too much to be repairs, so most people give em flying lessons.
Lots of still good parts in them...and you can test each one prior to re-use
to make sure it wasn't the part that caused the trouble.
( ohm meter and capacitor tester/reader is all ya need )
Leave the parts ON the board, to let you ID what kind of ckt they were in
and for lead ID....usually marked ON the board...
Pick the board for parts AS yopu need them....don't strip it clean...you'll
lose the ID I just mentioned.
Just remove the board from the 'chassie' and discard the non-electronic
section to save on storage space.

Be XXX carful about the pix tube....DO NOT mess with the wire that leads up
to the side of the tube...as the tube stores the high voltage (up to 25,000v)
for very long periods after the set is shut off!

Use a PLASTIC rod to pry the wire off (use force...don't worry about breaking
the wire or the HV coil it leads to) the tube...and don't touch the now
exposed belly button as you extract the ckt board.

VCR's and fried sterios ( portable or not) have no such HIGH voltage, so
you can just start hacking.
Study as you go...you learn how the stuff is made as you go along.... and
in general , get to see how it works.

Zapped computers have very little you can reuse for RADIO......just a few
capacitos, resistors....may a few regulators, diodes.....NOT worth paying
over a couple dollars for...

If you head off to a ham fest.....you'll wish you had about $70.oo on you
I generally spend over $20...and never yet spent over $70....and I stock
up like Byrd going to the S. Pole too.
Go thru 2 times: 1st time to spot where stuff is, and to see if a 2nd table
has same thing for less cost.
Waiting also until JUST before closing, some vendors will GIVE you the stuff
just so they don't have to take it all the way back home!

Get somthing to eat so you won't be 1/2 starving while trying to concentrate
on what you want to get...

Good luck! Have fun!

--
Randy KA1UNW              If you get a shock while
                         servicing  your  equipment,         "Works for me!"
randy@192.153.4.200             DON'T  JUMP!                     -Pete Keyes
                     You might break an expensive tube!


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