[0rangutan]

Hi all,
 
I am getting very confused by a section of Cardas quad core cable that fails a multimeter continuity test.
 
The cable is 2m long, unterminated at each end and in great physical condition.
 
Using my multimeter in continuity test mode:

1. If I test the shield, I get a confirmation signal
2. If I test red, green, white or black, I get no signal at all from any of them.

 
I am as sure as I can be that the cable is intact along its length and I have re-tested the multimeter on other cables and it appears to work perfectly for those, just not the Cardas cable.
 
Why does the test fail?  Have I missed something obvious?
 
Any help much appreciated, thanks.
 
John

 

[Todd R]

Quote:

Hi all,
 
I am getting very confused by a section of Cardas quad core cable that fails a multimeter continuity test.
 
The cable is 2m long, unterminated at each end and in great physical condition.
 
Using my multimeter in continuity test mode:

1. If I test the shield, I get a confirmation signal
2. If I test red, green, white or black, I get no signal at all from any of them.

 
I am as sure as I can be that the cable is intact along its length and I have re-tested the multimeter on other cables and it appears to work perfectly for those, just not the Cardas cable.
 
Why does the test fail?  Have I missed something obvious?
 
Any help much appreciated, thanks.
 
John

 
Yes you have. 
All Cardas wire is enameled, meaning each strand is coated to prevent oxidation. Cardas wire must be tinned before use which burns off the enamel and coats the wire with solder. 
You must use a solder pot, or if the wire is smaller gauge, you can use a soldering iron to tin the wire. 
The alternative is to sand the coating off, or use some type of solvent, but tinning is preferred. 

 

[0rangutan]

Thanks!  That makes perfect sense now.