Testing Jigs

[zpyder]

Hey everybody...

I know some of you out there have some pretty sophistocated set ups.  I'd like to talk about the good and the bad of test jigs.  A test jig being a unit that you can plug a newly-built circuit into and listen without boxing it up.  I saw an example of somebody's test jig recently, but can't remember whose or where...

So to get things rolling-

Question:
Any good ideas for pots??  These seem to be a little more complicated to include in a test jig.  all circuits use different values.  And soldering them on and back off.... Any good tips on using pots in a test jig?

Good Idea:
Brainstorming on my soon-to-be new test station I figured a smart and EASY thing to do would be to grab many alligator clips.  instead of temporarily soldering wires from a new circuit's in, out, +9v, and GND to the jig (time consuming, can damage board, wastes solder), install wires onto the jig with alligator clips on the other end, and then just clip them to the  component lead nearest the net to be ported.


Please contribute your ideas and PICTURES if you have some!

zpyder

[Mordred]

Hey Zpyder.
I built a soldering jig recently, but I have been thinking about modding it to a test jig
http://www.diystompboxes.com/smfforum/index.php?topic=50757.0

The pics are available here
http://uk.pg.photos.yahoo.com/ph/alln_jedi/album?.dir=a078re2&.src=ph&store=&prodid=&.done=http%3a//uk.photos.yahoo.com/ph//my_photos

What I was thinking was a piece of thin aluminium shaped and drilled to connect the jacks to allow an earth to be made in place of using the chassis. if the aluminium is drilled, thenit can be fitted onto the hacks and mounted to the perspex wall.
I was also thinking about mounting a few mounting posts to be able to screw a circuit board into the jig to fix the board to while testing.

I don't know if anyone else has a similar or better idea.
but I like the idea of a test jig as well as a soldering jig

Allan.

[boogietube]

http://www.diyguitarist.com/
He calls it the " D.I.Y. Guitar Effects Prototyping Board"

[Seljer]

I've only made myself a small box with 2 jacks and a toggle switch switch, with 4 terminal block style connectors for the wires for in/out/gnd/+9V

[boogietube]

Here's another one :
http://beavisaudio.com/Projects/

[Pushtone]

I really liked diyguitarist.com's mounted pots.
I really like how Beavisaudio.com used a terminal strip.

I combined the two to get a breadboard with mounted pots/jacks AND and terminal wiring.
Everything ends in an alagator clip. The jacks, pots, 9V and ground all end in a clip.
A good interface. Keeps leads from breaking and is most flexible.
Used for breadboarding and PCB testing.

Also added a DC 2.1mm jack to switch between an adapter and a battery (using a batt snap soldered to a 2.1mm plug).
Also added a power LED which became a necessity.
Also added a cheap test tone generator.

At the bench I plug the output into a old computer speaker.
If the circuit has a heartbeat I carry the test jig over to the amp. Very portable.

[Gilles C]

Here is mine





I like to be able to test 2 effects at the same time or together if I want. And I like to have a breadboard to test a few things without having to solder everything.

Gilles

[R.G.]

Here's the original, from back in 1998:




Bigger and fancier can be a help, but it's simple to get started with a small one. This is just a piece of aluminum angle screwed to the bottom of the breadboard metal plate itself.

[RedHouse]

Here's mine (1st build in 1987), I needed a shielded container for testing Overdrive and Fuzz type circuits



Originally it was in a Walkers Shortbread tin, a few years ago I transplanted it into this tin, there's a wire soldered onto the underside of the lid and connects to the bottom half, when the lid is closed it's a shielded box.

(that's DougH's Highway-89 in test)

[zpyder]

RedHouse-

I've tested circuits in a tin just like the one you use, but I had to use an alligator clip to make the ground connection to the chassis.. my solder would stick to it... did you use any special tricks to get solder to stick to the tin?

zpyder

[Seljer]

Couldn't you just use the input jack's sleeve thats touching the chassis?

[RedHouse]

RedHouse-

I've tested circuits in a tin just like the one you use, but I had to use an alligator clip to make the ground connection to the chassis.. my solder would stick to it... did you use any special tricks to get solder to stick to the tin?

zpyder

Yep, the special trick is to file some of the plating down to the base metal, then the solder will stick.

I'm sure one could just solder a wire to the ground lug on the jack, but make sure you file away the paint in that area to get a decent ground.

[zjokka]

After I started out I immediately made something from an old stereo. Certainly you want to input and output jacks mounted somewhere. I also mounted a number pots



In pratice, I've come to use the pots less and less, though the jacks stands. This is because

--> you can plug minipot straight into the breadboard and then just plug (and replug) the wires from the board in the breadboardo.
--> too many alligator clips give you a headache
--> too many different

[lumpymusic]

I'm building a test jig for setting transistor bias.
Three of those LED volt meters. Each one has one
of those micro pincer clips for the + lead.
Clip each lead to E B C. Clip the - lead(s) to
ground. Then as you adjust the trim pots
on all the legs of the transistor, you see
all three voltages at once. Seems like it
would me a LOT faster and less destructive
than moving the DMM lead around several
times.

Lumpy