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Old May 3rd 05, 06:22 PM
Tim Shoppa
 
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Default Large PCB source for dead bug homebrewing?

Many years ago (like, 20) I bought many 24" x 24" sheets of
single-sided PCB that I've been using to homebrew dead-bug style and
for other activities like soldering together little shielded boxes.
Probably mail-order from Fair Radio.I'm sure I paid very little for the
stuff at the time, probably a few bucks a sheet. Now my stash is
almost gone. Anyone care to recommend a good cheap supplier for
similar single-sided PCB? I'm not picky as to phenolic vs glass-epoxy
or whatever, I just need a good ground plane. Big pieces are good but
I can live with little pieces too.

The stuff I got 20 years ago was, for some reason, pre-tinned. (Maybe
this is why it was so cheap?). That was nice because I don't have to
clean off my dirty fingerprints when coming back to a project after a
few weeks or a few years :-). Pre-tinned is a big plus.

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Old May 3rd 05, 10:08 PM
Joerg
 
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Hello Tim,

See if there is a PCB manufacturer within resonable driving distance and
ask for scraps. That's how I got a huge stash decades ago. Single and
double sided, the good stuff (FR4). But it has to be picked up, in my
case they wouldn't have gone through the trouble of packaging and
mailing it. Basically it had to be no more effort on their part than a
walk to the dumpster would have been.

Mine weren't tinned though. Also, I am not sure if constantly touching a
pre-tinned board during experiments would be too healthy.

Regards, Joerg

http://www.analogconsultants.com
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Old May 3rd 05, 10:15 PM
Joerg
 
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Default

Hello Tim,

Just one more thought: I use "living-bug" arrangements almost
exclusively. Every once in a while I cut up some strips so they fit the
most popular "underbellies" of chips. Then I glue the strips onto the
large panel and the chips on top of the strips in a rider's fashion.
Ground connection can be achieved by slightly bending down a pin, the
rest gets wired up Sauerkraut style like usual. When stray capacitance
is critical I take washed wood strips instead of copper clad. Makes for
a really nice excuse to eat another Haagen Dasz.

This avoids having to think in reverse pinout and it often looks nicer,
too. Plus you can still see the "CD4007" on the chip.

Regards, Joerg

http://www.analogconsultants.com
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Old May 3rd 05, 11:47 PM
John Miles
 
Posts: n/a
Default

In article ,
says...
Hello Tim,

Just one more thought: I use "living-bug" arrangements almost
exclusively. Every once in a while I cut up some strips so they fit the
most popular "underbellies" of chips. Then I glue the strips onto the
large panel and the chips on top of the strips in a rider's fashion.
Ground connection can be achieved by slightly bending down a pin, the
rest gets wired up Sauerkraut style like usual. When stray capacitance
is critical I take washed wood strips instead of copper clad. Makes for
a really nice excuse to eat another Haagen Dasz.

This avoids having to think in reverse pinout and it often looks nicer,
too. Plus you can still see the "CD4007" on the chip.


Or you can just bend all but the ground pins outward from the base of
the chip (e.g.,
www.speakeasy.net/
~jmiles1/ke5fx/492ap/large/close1.jpg). The pins won't break if you
don't flex them more than once or twice.

Sometimes I'll use a drop of cynaoacrylate adhesive to hold the chip
into place if there are few or no grounded pins, but it's rarely
necessary.

This also works for SOICs and even TSSOPs, as long as you don't bend the
pins more than once.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------


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Old May 4th 05, 07:53 PM
Joerg
 
Posts: n/a
Default

Hello John,

Or you can just bend all but the ground pins outward from the base of
the chip (e.g., www.speakeasy.net/
~jmiles1/ke5fx/492ap/large/close1.jpg). The pins won't break if you
don't flex them more than once or twice.


But then I won't have an excuse to eat another Haagen Dasz bar :-(

Regards, Joerg

http://www.analogconsultants.com
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Old May 4th 05, 08:57 PM
 
Posts: n/a
Default

From: "Tim Shoppa" on Tues,May 3 2005 10:22 am

Many years ago (like, 20) I bought many 24" x 24" sheets of
single-sided PCB that I've been using to homebrew dead-bug style and
for other activities like soldering together little shielded boxes.
Probably mail-order from Fair Radio.I'm sure I paid very little for

the
stuff at the time, probably a few bucks a sheet. Now my stash is
almost gone. Anyone care to recommend a good cheap supplier for
similar single-sided PCB? I'm not picky as to phenolic vs glass-epoxy
or whatever, I just need a good ground plane. Big pieces are good but
I can live with little pieces too.


Ebay might be good as someone else suggested. The best bet
for low CO$T material is to sweet-talk a PCB maker for left-
overs...if one is in your neighborhood. I've gotten fairly
good prices from www.circuitspecialists.com on double-sided
stock (comes in protective plastic envelope).

The stuff I got 20 years ago was, for some reason, pre-tinned. (Maybe
this is why it was so cheap?). That was nice because I don't have to
clean off my dirty fingerprints when coming back to a project after a
few weeks or a few years :-). Pre-tinned is a big plus.


Cleaning OLD PCB stock the "green" way -

Sprinkle any kind of table salt on the PCB stock, then take
half a lemon and rub it on the salt. Most of the blackened
oxide will disappear!

I tried that late last year on some 4" x 8" double-sided
phenolic substrate PCB stock after seeing all those "green"
site remarks that I didn't really believe. It WORKS! :-)
Those pieces had been sitting in the back of the workshop
for about 35 years.

I did "cheat" a bit. Have a year-round producing lemon
tree and my wife had some coarse salt left over from a
canning experiment. Zero cost trial...lemons at the
markets can run 50 cents each. The residue can easily
wash down the sink, don't need any gloves, nothing toxic.
Result is easily solderable although for best appearance,
some cleaning with a bleach-containing kitchen cleanser
will make it shiny and spotless.



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Old May 5th 05, 09:27 AM
Watson A.Name - \Watt Sun, the Dark Remover\
 
Posts: n/a
Default


"Joerg" wrote in message
...
Hello Tim,

See if there is a PCB manufacturer within resonable driving distance

and
ask for scraps. That's how I got a huge stash decades ago. Single and
double sided, the good stuff (FR4). But it has to be picked up, in my
case they wouldn't have gone through the trouble of packaging and
mailing it. Basically it had to be no more effort on their part than a
walk to the dumpster would have been.

Mine weren't tinned though. Also, I am not sure if constantly touching

a
pre-tinned board during experiments would be too healthy.


Why is that? Lead? I thought that paint with lead in it was a lot
worse.

Regards, Joerg

http://www.analogconsultants.com



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Old May 5th 05, 09:37 AM
Watson A.Name - \Watt Sun, the Dark Remover\
 
Posts: n/a
Default


"Joerg" wrote in message
om...
Hello Tim,

Just one more thought: I use "living-bug" arrangements almost
exclusively. Every once in a while I cut up some strips so they fit

the
most popular "underbellies" of chips. Then I glue the strips onto the
large panel and the chips on top of the strips in a rider's fashion.
Ground connection can be achieved by slightly bending down a pin, the
rest gets wired up Sauerkraut style like usual. When stray capacitance
is critical I take washed wood strips instead of copper clad. Makes

for
a really nice excuse to eat another Haagen Dasz.

This avoids having to think in reverse pinout and it often looks

nicer,
too. Plus you can still see the "CD4007" on the chip.


Back in the early '70s I got some prototype boards from a company that
made aircraft receivers. They used four push-in pins, one for each lead
of the four corners of the IC. Two of these are usually power and
ground, pins 7 or 8 and 14 or 16. These four hold the chip up off the
board, and the other pins are wired spaghetti style, which I presume is
the same as your sauerkraut style.

Speaking of this.. Last Sunday at our monthly compouter club meeting
someone donated a homemade S-100 system to the consignment table, but no
one bought it, so it ended up on the freebies table later, probably then
into the trash later. It had a chassis and box pop riveted together,
and the S-100 bus was all wire wrapped. A lotta love and time went into
building that way back in the late '70s.

Regards, Joerg

http://www.analogconsultants.com



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Old May 5th 05, 09:45 AM
Watson A.Name - \Watt Sun, the Dark Remover\
 
Posts: n/a
Default


"John Miles" wrote in message
...
In article ,
says...
Hello Tim,

Just one more thought: I use "living-bug" arrangements almost
exclusively. Every once in a while I cut up some strips so they fit

the
most popular "underbellies" of chips. Then I glue the strips onto

the
large panel and the chips on top of the strips in a rider's fashion.
Ground connection can be achieved by slightly bending down a pin,

the
rest gets wired up Sauerkraut style like usual. When stray

capacitance
is critical I take washed wood strips instead of copper clad. Makes

for
a really nice excuse to eat another Haagen Dasz.

This avoids having to think in reverse pinout and it often looks

nicer,
too. Plus you can still see the "CD4007" on the chip.


Or you can just bend all but the ground pins outward from the base of
the chip (e.g.,
www.speakeasy.net/
~jmiles1/ke5fx/492ap/large/close1.jpg). The pins won't break if you
don't flex them more than once or twice.

Sometimes I'll use a drop of cynaoacrylate adhesive to hold the chip
into place if there are few or no grounded pins, but it's rarely
necessary.

This also works for SOICs and even TSSOPs, as long as you don't bend

the
pins more than once.

-- jm


What's the board in? A receiver? What's it do?


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