Lengthening iron leads

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surfsup
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Lengthening iron leads

Post by surfsup »

What's the proper method to extend transformer leads?
Bruciep07
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Location: Central NJ

Re: Lengthening iron leads

Post by Bruciep07 »

I dont know if I have the correct answer for you, but I can share my experience. I have done it successfully 2 different ways...

1) Strip enough insulation off of the 2 leads to be connected and fold each stripped end in half, essentially making 2 "hooks", join the hooks together, pinch them so there is a decent mechanical connection, then solder them together. Use adequate shrink tubing to eliminate the possibility of a sharp piece of solder puncturing the tubing. I used 2 pieces on top of one another, just in case. This method works when I don't have room for a bulky connector, maybe where the wire twists around a socket or other wires and a butt connector would not make that possible.

2)Butt connectors (Gasp!!! :shock: ) I found that insulated butt connectors sold at McMaster Carr (called sure-connect sealed butt splices) work really well. The contain solder inside the joint, plus have heat shrink tubing pre-applied, so when you heat the joint, it seals and solders, plus you have the mechanical butt connector holding it together. I will still add another piece of shrink tube on top for good measure. These work great but are a bit bulky, as well as costly. But when you can score a good transformer off the bay for pennies on the dollar, to me, spending a few bucks to get the leads where I need them safely and securely is worth it.

Like I said, I'm sure there are better ways to do it, and some will probably disagree with my method of attack, but it has worked for me so far...
Happy building!
Bruce
ampgeek
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Re: Lengthening iron leads

Post by ampgeek »

Assuming a stranded-to-stranded assembly, I strip back ~3/8" on each, carefully straighten and loosen the conductors on each piece and push the ends together, end on, with a vision of trying to get one-to-one contact of each strand from each end. Push any outliers back into the "herd" and solder. I then wrap a strip of ~3/8" electrical tape around the joint to bring it up to the insulation level and shrink wrap it.

Cheers,
Dave O.
Kazooman
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Rockin' In Space

Post by Kazooman »

If you are planning to play your amp while in earth orbit, you might want to follow the NASA standards:

http://www.hq.nasa.gov/office/codeq/doctree/87394.pdf

Seriously, page 83, section 19.9 shows the classic Western Union/Lineman Splice. It provides strong mechanical strength and great electrical contact. Apply solder and follow up with a layer (or two) of shrinkwrap and you are done.

[IMG:602:175]http://i56.tinypic.com/2up5nd2.jpg[/img]
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Phil_S
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Re: Lengthening iron leads

Post by Phil_S »

WU is THE splice to do if you can. Unfortunately, it is bulky and difficult to do well with stranded wire. In addition, you might be dealing with short leads on the transformer, making it hard to strip enough to do it properly. After you are done with it, you have a big hunk of inflexible wire lead.

As a practical matter, I think the two hooks is the way to go, with maybe a little twist below the hook. Good luck.
Cliff Schecht
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Re: Lengthening iron leads

Post by Cliff Schecht »

I strip back about 3/8" as well, put the wire pieces side by side, twist them together solidly, solder and heatshrink. This works fine because the leads shouldn't ever be under any kind of real stress anyways. Sometimes I'll put the two pieces of wire together with the strands going the same direction (i.e. two wire pieces touching and twist the ends together) and do the repair this way, kind of like you do with shielded cable where you add in a new wire and it comes out the "wrong" end of the heatshrink. Pictures would probably help, perhaps I'll post some later.
Cliff Schecht - Circuit P.I.
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Baxtercat
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Re: Rockin' In Space

Post by Baxtercat »

Kazooman wrote: [IMG:602:175]http://i56.tinypic.com/2up5nd2.jpg[/img]
Haha! C'k out the art. It's like an Escher drawing....the ends of each twist start then stop the wrong direction.
[We know what they meant.]
Guitar Bob
Zippy
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Re: Lengthening iron leads

Post by Zippy »

An insulated terminal strip works also.
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