Extending primary leads on OT?

[glebert]

I have an Eden E300T 300 watt tube head that had a blown OT. I got a decent deal on an NOS SVT CL transformer (no replacements for original that I could find). One problem I have is that the lead for the OT primary CT is not long enough, by about 5 or 6 inches. Is there a way to safely extend this lead or do I now have two expensive boat anchors?

Here is a picture of the SVT OT, the primary CT is the red/white wire:


Thanks in advance,
Greg

[xtian]

Sure, you can solder extensions to the wires. The primaries carry 120vAC, so the wire insulation and shrink tubing needs to capably handle that much voltage (not a tall order at all).

Wait...you said "primary CT" which doesn't make sense to me. Only the secondaries have CTs.

[Helmholtz]

Sure, you can solder extensions to the wires. The primaries carry 120vAC, so the wire insulation and shrink tubing needs to capably handle that much voltage (not a tall order at all).

Wait...you said "primary CT" which doesn't make sense to me. Only the secondaries have CTs.

It's an OT.

[glebert]

Sure, you can solder extensions to the wires. The primaries carry 120vAC, so the wire insulation and shrink tubing needs to capably handle that much voltage (not a tall order at all).

Wait...you said "primary CT" which doesn't make sense to me. Only the secondaries have CTs.

This is an output transformer. By CT I mean the lead that feeds the B+ voltage to the primary side of the OT. On this amp this is about 650V.

[Enzo]

It is a WIRE, of course you can extend it. It is just a wire. SPlice a longer wire to it and cover the splice with some heat shrink tubing. If you want to be cool about it, use the same color wire.

[xtian]

I stand whatevered.

[glebert]

It is a WIRE, of course you can extend it. It is just a wire. SPlice a longer wire to it and cover the splice with some heat shrink tubing. If you want to be cool about it, use the same color wire.

Mostly didn't know if I needed to use HV wire and connectors, and if I should solder splice to the existing wire (and if a certain type of splice is best) or leave the existing connector and use make a male/female pigtail, etc. Looking around my bins most of the wire seems to only be rated 300V, have some that says 300/500, but am not up on wire ratings.

[nevetslab]

Mostly didn't know if I needed to use HV wire and connectors, and if I should solder splice to the existing wire (and if a certain type of splice is best) or leave the existing connector and use make a male/female pigtail, etc. Looking around my bins most of the wire seems to only be rated 300V, have some that says 300/500, but am not up on wire ratings.

You could always add heat shrink all the way over your additional 300V rated hook wire used to extend the C/T lead. Alpha FIT 221 heat shrink carries a voltage rating of 600V, so that would certainly take care of the voltage rating.

[g1]

I don't really care for the idea of using the existing connector, but you could use a crimp type butt connector, then heatshrink over. Or solder splice w/heatshrink as mentioned.

[Enzo]

I can't imagine anything more reliable than a standard Western Union splice, soldered and tubed.

[nosaj]

I can't imagine anything more reliable than a standard Western Union splice, soldered and tubed.

Yea your not using it like a rope should be good enough for a lifetime.
https://en.wikipedia.org/wiki/Western_Union_splice
nosaj

[Chuck H]

I don't even take it THAT far. It's not a tether or any sort of physical support or stress point. I usually just spread the stranding on each end I want to splice and then sort of insert them into each other, if you get my meaning. Then I squeeze down the spread ends and give a little twist to tighten it up. Solder and add shrink tube... It makes for a skinnier, smoother looking splice if appearances matter. Otherwise the Western Union splice is certainly more reliable.

[eschertron]

Yea your not using it like a rope should be good enough for a lifetime.
https://en.wikipedia.org/wiki/Western_Union_splice
nosaj

Well, I learned something new today. I always called it "twisting two wires together"



edit: but upon reflection, I can well imagine back in the telegraph days there needed to be a standard for the splices, and plenty of 'em - I doubt there weren't too many 1000-mile-long rolls of telegraph wire being spun 150 years ago.

edit: I see the WU splice is meant to be a structural member, the wire solid core and stiff!

[Enzo]

For what it is worth, to me twisting two wires together is a pigtail splice.

[glebert]

This is all really helpful to me. My splice game has always been weak because I would do it so infrequently and was never shown different ways to splice. I definitely used the term pigtail improperly above because to me the pigtail was the section of wire that was added, not the wire joint itself.