OT: Testing cables?

[snorky]

Hi All,

I built some guitar cables yesterday from good quality cable and Switchcraft jacks.  When I play thru one of the cables, the output is much quieter than the others.  The continuity is fine (tip to tip and sleeve to sleeve).  What can I do to test this?  I assume there is either a short, or higher resistance somewhere?

Sorry for this "dumb" question.

TIA!

- Mark

[mirza]

try respldering...less solder and smaller temperature..be quick

[smoguzbenjamin]

Try testing the impedance of the cables, or DC resistance at least. A high impedance cable could mean a loss in signal volume

[Mike Burgundy]

yup, sounds like a faulty solderjoint.
hih

[Processaurus]

If it isn't a cold solder joint messing up your cabling situation its possible that there's a high resistance short between the tip and the sleeve.  A quick test is to measure the resistance between  the tip and sleeve with your meter on the highest setting; it should read as an open load.  Good  quality cable like Belden or Canare has a semi-conductive sleeve between the shield and and insulation, I think it has something to do with minimizing static making crackles when the cable is moved or stepped on etc.  If any of the tip's stray wire strands are touching this it will cause a partial short and end up make your guitar signal quieter.

[snorky]

Thanks for all the suggestions!  I'm gonna do some for work on this today.

1) One strange thing.  I measured the resistance between tip and sleeve on the connector and it's OPEN.  I measured the resistance between the core wire and the shielding and it's OPEN.  BUT, when I put the cable (without soldering) on the connector, it's shows a few K ohm like there's some small connection.  This resistance seems to vary.  I don't see how this is possible.

2) What's the best procedure for soldering the shielding to the sleeve?  It seems like you have to go to the inside of the sleeve because the jack cover won't fit otherwise.  But it's kind of awkward to solder to the inside.  I've dug around on the 'net a bit about this, but can't find any good pictures of specifically how this is done.

TIA (again)!

- Mark

[Paul Perry (Frostwave)]

That slightly conductive plastic stuff has probably shorted somewhere.
And one of the soldered joints probably isn't. I hate making cables.
But if you are intending to make cables for the rest of your life, make a 'test box' so you can plug the cable in & have the meter attached without hands, so you can wriggle the cable to test it.
Or (better) buy Whirlwind.

[Processaurus]

To get your shield wire soldered to the plug,  a pair of of those silver medical clamps (like stoners use as roach clips) comes in handy, you can clamp the shield wire to the plug between the insulation and where you're gonna solder it on,  this holds it steady and also is a heat sync so the shield won't melt through the insulation.

[SoundTech]

BUT, when I put the cable (without soldering) on the connector, it's shows a few K ohm like there's some small connection.

How are you making the connections if you are not soldering?  Be sure to make sure none of your flesh is connecting tip and sleeve, or you will get resistance across you.  If the cable is open between conductors when no connector is attached, and you thoroughly checked the cable to make sure there are no intermittent shorts, be sure that the insulation around the center conductor IS NOT touching the sleeve anywhere.  That can make a high resistance connection between conductors.

[SoundTech]

(Double post deleated)

[snorky]

BUT, when I put the cable (without soldering) on the connector, it's shows a few K ohm like there's some small connection.

How are you making the connections if you are not soldering?  Be sure to make sure none of your flesh is connecting tip and sleeve, or you will get resistance across you.  If the cable is open between conductors when no connector is attached, and you thoroughly checked the cable to make sure there are no intermittent shorts, be sure that the insulation around the center conductor IS NOT touching the sleeve anywhere.  That can make a high resistance connection between conductors.

I wasn't soldering the connection because I was just testing to see if there was some conductivity even though there wasn't on either the plug or the shield/center conductor separately.  If the central insulation does conduct slightly, that could have been the problem.  I redid a number of plugs last night, and they're all OK.  The only difference is that there is more distance between the central wire, and the shielding.  I'm not really sure what I did differently, but I'm happy with the connections now.

Thanks again for everyone's help on this!

- Mark