Soldering Cables?

Wireneck

New member
I bought some cable and connectors to make a few custom patch cables for my pedal board. This is NOT my first attempt at soldering cables but this is the first time that I have ever had any trouble.
I keep getting a weak signal from the finished cable. If I plug in on my distortion channel it is almost like I am rolling off the gain. I have tested the cables with my multimeter checking for continuity and there don't seem to be any shorts between tip and sleeve. The cable has a really obnoxious "shield" braid that I am having a lot of trouble unraveling enough of to get it soldered onto the sleeve. Would poor grounding cause the issue I am describing?
I re-soldered the first two that I did and got them working like they should but I haven't figured out what I did differently. This is very frustrating.
Any tips or advice are greatly appreciated. Is there any other way I can test the cable with my multimeter beyond, testing for continuity from one end to the other?
 

MajorTom

New member
Does the cable you are using have a black layer of film on the inner conductor? If so, I have read that a particular type of cable has that, and if that film touches the tip connection (it is in contact with the shielding throughout the cable), it acts as a "semi" conductor, like maybe 20, 50, 100K ohms which loads down the pickups and sucks tone. The fix is to strip away enough of that black stuff so it won't touch the tip connection.

Its kinda a "superstition" with me, but when I solder inside a guitar or a cable, I always make sure that all the strands (or at least only missing a couple) are soldered. I re-did a connection once inside a guitar, maybe it wasn't sounding "right" somehow...don't remember what prompted me to do it.... Anyway it was missing several strands of the shield, maybe 30 - 50%, and afterward it sounded much better; that fixed it. It may not have been the stray strands - it might have been a cold solder joint, something else I did, or maybe my imagination...? but it sure doesn't hurt to get all your strands soldered, and I just always do that now. I use a scratch awl to un-weave the shield, but maybe yours is something I have not encountered before.

The only other thing I can think of is a cold solder joint.

I would check both the inner conductor and ground resistance from one end to the other, to make sure each is near zero ohms. I would also check across the inner conductor and shield using a high resistance scale - it should be infinite resistance - make sure not to touch the metal part of the probes with your fingers, otherwise you'll be measuring your body's resistance, and get a couple hundred K or so.
 

MajorTom

New member
You aren't using silver solder are you? I have heard that stuff is difficult to get a good joint. I guess it takes a hotter iron or ?
 

Wireneck

New member
I'll have to check but I am pretty sure its rosin core, I picked up at Radio Shack a while back. I am at a loss for the night. I have 3 fully functional patch cables and I have re soldered enough times to have done at least 4 more.
 

Anfontan

Banned by eurt
I bet it could be some of the new 'lead free' solder that is now available. It is harder to melt and doesn't have a shiny appearance that lead solder had. You might need to add some flux to the solder to get a better connection.
 

MajorTom

New member
I'll have to check but I am pretty sure its rosin core, I picked up at Radio Shack a while back. I am at a loss for the night. I have 3 fully functional patch cables and I have re soldered enough times to have done at least 4 more.

Rosin core means it has flux inside, it does not designate the alloy. Electrical solder has traditionally been a lead/tin (easy to solder and get good connections), but some is a silver alloy - the container should indicate which type it is. If it is silver, I would bail out on that and get some 60/40 (lead/tin) rosin core solder. Or maybe someone experienced with the silver stuff can educate us how to get good results.
 

dgatwood

is out. Leave a message.
Well, lead-free solder is harder to work with, but usually you just get cold solder joints that fail/fracture sooner. The electrical conductivity should be established by the material touching even without the solder being there, so if you're having conductivity problems, it probably isn't the solder.

My guess would be that there's a partial short or high resistance in the signal pin. That said, it is remotely possible that the wire is just not suited for that purpose. For example, if the capacitance per foot is too high, you'll get high frequency loss.
 

gcapel

boom box recordings
Make sure the shield (foil or braid) is connected with the sleeve. I will draw a diagram to help. How many conductors are in the cable in addition to the shield?
 

ggunn

Crystal Flavolian
Is there any other way I can test the cable with my multimeter beyond, testing for continuity from one end to the other?

Yes. Check for resistance with your meter. For a short cable you should see only a fraction of an ohm from tip to tip and sleeve to sleeve. Also, as someone else has posted you should see very high or infinite resistance from tip to sleeve.

You have to be very careful when soldering some types of coaxial cable, especially if you are having to heat the shield for a long time to get the solder joint to "take". When you are soldering the shield, sometimes the heat of your work can partially melt the insulation between the shield and the inner wire(s) and result in pinhole micro-shorts between the tip and sleeve connections. From what you say I think it's likely that that is what you are seeing.

What can help this is using one of those little clip-on heat sinks that they sell at Radio Shack. Clip one on the shield between where you are soldering and where the inner wires come out of the shield, and that will divert the heat flow.
 

Wireneck

New member
Thanks for all the info guys. The cable is Canare with a braided shield. The cables I am soldering are very short like 8-12 inch patch cables. The solder says 60/40 rosin core "this product contains lead".
I will take some measurements with my meter in a little while and try some of the tips you guys have offered. I have never had this much trouble with any of the previous cables I have soldered. I know it has to be something I am doing wrong though because some of them are working properly now. Go figure......
 

ggunn

Crystal Flavolian
I know it has to be something I am doing wrong though because some of them are working properly now. Go figure......

Intermittent cable failure is typical of the insulation melting problems I was talking about. If you wiggle the cables or twist them around, the wires can move to where the short goes away, but move them again and the problem comes back.

It doesn't sound to me like this is a problem with solder makeup or cable capacitance.
 

MajorTom

New member
This the cable you're using? Looks like good quality.
http://www.canare.com/ProductItemDis...oductItemID=61

In that pic - do you see that black ring in between the shield and the inner conductor? That apparently is the black stuff I referred to earlier - that must be actually part of the shield, and is a conductor; it must be the "carbon" part of the "The proprietary double Carbon/Braid Copper shield construction" in the specs. Since it is connected to ground (being right against the copper braid), if it touches the inner conductor terminal (the "hot"), it will cause problems. You have to strip that black stuff back far enough to where it cannot touch.

If you did not make a concerted effort to keep it from touching the inner conductor, that would explain your symptoms, and how it got corrected after re-soldering it a time or 3...
 
Most top quality cable has that conductive fabric, It makes the shield 100% coverage whereas the copper braid only yields about 90%. all EMF and RFI noise will be blocked from getting into your signal chain. I have had similiar problems with the fabric making high impedance shorts to the center conductor, You just have to make sure you remove enough. I agree using silver solder is harder to master, but once you do it makes for very low resistance joints, silver is the best conductor.
VP
 

Wireneck

New member
Now this is all starting to make sense. If the black part is part of the shield then I have been basically butting it right up against the "tip" connector when I pull the tip wire through the loop. I had no idea, amazing what you can learn on the internet. :)
I also picked up one of the heat sink clips. I will give it another go later with the clip and peeling back more of the black. I will report my results. Thanks for the info as usual fellas!
 

Lt. Bob

Spread the Daf!
Yes. Check for resistance with your meter. For a short cable you should see only a fraction of an ohm from tip to tip and sleeve to sleeve. Also, as someone else has posted you should see very high or infinite resistance from tip to sleeve.

You have to be very careful when soldering some types of coaxial cable, especially if you are having to heat the shield for a long time to get the solder joint to "take". When you are soldering the shield, sometimes the heat of your work can partially melt the insulation between the shield and the inner wire(s) and result in pinhole micro-shorts between the tip and sleeve connections. From what you say I think it's likely that that is what you are seeing.

What can help this is using one of those little clip-on heat sinks that they sell at Radio Shack. Clip one on the shield between where you are soldering and where the inner wires come out of the shield, and that will divert the heat flow.

this is what I was gonna guess. Melt that insulation a bit and you can have enough conductivity to cause signal loss without it showing up on a continuity tester.
I actually just went thru this exact thing. Finalizing my pedal board and making very short permanent connectors. Everything checked out fine ...... went to the gig and had massive signal loss. Had to play with my amp more than twice as high as usual plus it sounded like crap.
Redid the cables and it was fixed.
I still don't know for sure what it was but I suspect melted insulation.
 

Anfontan

Banned by eurt

I recall having a run-in with that conductive black insulation about 12 years ago or so. I always check cables I build with an ohm meter or continuity tester and no matter how clean my connections were there was a major short! Finally I called the music store and found out what the problem was-what a headache that cabling caused!
 

Wireneck

New member
Yes, the black layer seems to be the culprit. On the cables that I had redone a few times and got working, the black was back enough that it wasn't touching. I went back and redid the others and they are now working fine as well. I just assumed the black was part of the "tip" wires jacket. Boy was that a bad assumption hahaha. Thanks again guys!
 
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