Cable tester DIY

Started by vendettav, August 02, 2011, 06:22:09 AM

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vendettav

is there a chance of making a cable tester? by a chance im talking a simple or mediocre project that won't run me broke

just lately all these cable issues i was getting i got to somewhat not trust cables at all.. .what if they fail at me on gigs..?

so.. yeah.. a Cable tester!
check my music HERE

Shredtastic psycho metal!

CynicalMan

Make a box with an LED and two guitar cable jacks. Set it up like this (in series):

Battery + -> 4.7k resistor -> Jack 1 Tip
Jack 2 Tip -> LED -> Jack 2 Sleeve
Jack 2 Sleeve -> Battery -

Connect the cable between the jacks. If it's working then the LED will light up. If either of the cable's connectors is broken, or if they're shorted, then the LED won't light up.
If you want a diagram, I can put one up.

Thomeeque

 It can be pretty simple or pretty complicated, you should probably state first what features do you need.. You may read e.g. this review for inspiration.. T.
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Thomeeque

#3
Quote from: CynicalMan on August 02, 2011, 07:42:11 AM
Battery + -> 4.7k resistor -> Jack 1 Tip
Jack 2 Tip -> LED -> Jack 2 Sleeve
Jack 2 Sleeve -> Battery -

Jack 1 Sleeve -> Battery -, right?

Pretty clever! And if you would add some speaker in series with LED, you could check audibly for intermittent issues (As any guitar player knows, most guitar cable "failures" are noisy or intermittent connections that can drive us crazy. With the CT100 the microprocessor monitors the connection for brief open or shorted connections that the eye might not catch on the LED matrix. If any problem is detected, no matter how brief, it will show up as a steady lighted LED in the Intermittent column. So the procedure is that once the cable is plugged in, move the cable vigorously in all directions to see if any intermittent problems are indicated. Our procedure is to flex the cable near the plugs, and then run a rough grip over the full length of the cable to uncover any problems within. - on CT100 LED stays on, here you would hear pops and stuff)

T.
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CynicalMan

Oops, you're right. It should be jack 1.

R.G.

They're easy to make; as noted, LED, resistor.

However, there is a major easy-to-use cable tester I saw from the George L's cable people. It's a little box that takes a 9V battery, and on one end there are two brass rivets with an LED in the middle. Plastic molding makes the cable ends want to lie in grooves touching the brass rivets. It's just the battery, resistor and LED, but it's extremely well set up and easy to use. I think they sell them for a few bucks. This is one of those things that formed plastic was invented for. It's handy, does EXACTLY what's needed, and is compact and cheap. Testing a cable for shield continuity, tip continuity, and no shorts is literally 1-2 seconds and can be faster with practice.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

vendettav

actually i've thought about the simple LED between the jacks and all but yeah i was having teh behringer thing in my mind and i usualyl end up having an intermittent issue.. so how would i go about making something which would help me detecti that
check my music HERE

Shredtastic psycho metal!

Thomeeque

#7
Quote from: vendettav on August 02, 2011, 09:52:06 AM
actually i've thought about the simple LED between the jacks and all but yeah i was having teh behringer thing in my mind and i usualyl end up having an intermittent issue.. so how would i go about making something which would help me detecti that

And if you would add some speaker in series with LED..
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stringsthings

Quote from: vendettav on August 02, 2011, 06:22:09 AM
is there a chance of making a cable tester?

yes ... and here's another solution to your problem:

http://www.paia.com/proddetail.asp?prod=PFG&cat=14

project #30 is the "Tri-Test" Cord Checker ... it tests for:

1) continuity
2) internal shorts
3) intermittents

the circuit uses a 4001 NOR gate ( configured as four inverters ) and about a dozen everyday, regular resistors and capacitors ... i built one many, many years ago and it works exactly as designed ...

PRR

Intermittents are the blind-spot for any "quick" checker.

How about an iPod, iPod speakers, and adapter to put "any" cable in between? Play your tunez, plug the suspect cable, and wiggle the heck out of it. Either it plays dead, plays flawlessly, or cuts in/out.
  • SUPPORTER

Rodgre

I second the Craig Anderton Tri-test. It has been my cable checker since that book came out.

Now, I need to make a multi-version to test balanced/mic cables. Or just buy the Behringer one...

vendettav

#11
hmm ok that Andertone project seems to be good from your comments, i'll try looking into it :)
check my music HERE

Shredtastic psycho metal!

Thomeeque

#12
 Here's my extension of Alex's idea visualized:



Besides speaker for intermittents testing it adds one LED yet.


  • Functional cable would light both LEDs,
  • Cable with internal short would light RED LED only,
  • Interrupted cable would not light any LED.
  • Intermittents would cause audible pops, scratches and other ugly noises from the speaker.*

Now, when I think about it, maybe there could be yet third LED added (with it's own resistor probably), light when cable is plugged into J1 (using ring contact as stompboxes do), to indicate battery condition.

Tri-Test is way cooler, but this one does not need C/S toggle! :icon_mrgreen:

T.

* Edit: Hm, there's a problem :( Current is too small for the common speaker to make noises loud enough (and sufficient current would probably lower battery life too much).. Headphones could be used..
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Paul Marossy

I built Craig Anderton's simple cable tester from his book called Do-It-Yourself Projects For Guitarists. It's kept me from pulling out my hair a few times.

The more complex one in the book will also test for intermittent shorts, which are the ones that REALLY drive me crazy.  :icon_mad:


vendettav

hmm seems like i'll be working on a vero for the tritest or what's it called?
wil lit be legal (and fine) to post it here?
check my music HERE

Shredtastic psycho metal!

Paul Marossy

Quote from: vendettav on August 03, 2011, 12:30:04 PM
hmm seems like i'll be working on a vero for the tritest or what's it called?
wil lit be legal (and fine) to post it here?

As long as you're not copying anything directly and posting it here, I think you'll be OK.

vendettav

ok. actually i'd like to know how it all works. if I put all that's there in a freshly drawn schematic by me which isn't like the one he has there, then put the ideas he gives about the scheme in other ways and finally introduce a vero layout and of course credit him. will that still include some sort of violation? (just asking)
check my music HERE

Shredtastic psycho metal!


nexekho

Could you go uber overboard with this and have some kind of very sensitive comparator and flip-flop that'll light an LED if the return power isn't quite right?  I guess different leads will have subtly different resistances, etc. especially longer ones, so no.
I made the transistor angry.

Thomeeque

Quote from: Marcos Camara on August 03, 2011, 03:15:48 PM
Created by Brenno B.F. - Brazil

http://www.4shared.com/document/6sBEZAgI/Testador_de_cabos_de_audio_-_v.html

It's maybe too complex for simple guitar cable (most of the complexity is there due to 3-wire cables support) and it does not have support for intermittents detection.. T.
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