Sourcing 20 AWG solid core 600V wire to install the Time Delay Board

Hi all,

So I just received my time delay board in the mail last night. Assembly of the board went rather quickly. Before I started the rewiring, I read through the instructions. Unless I'm missing something, it appears I need an additional 2-3ft of wire to install the board. I ran to the local hardware store, and all I could find was 18 gauge braided hook-up wire and the voltage rating was questionable. I also knew that the wire wouldn't fit in the board eyelets.

After a quick search online, the smallest length I could find was 50ft spools, that run about $50 a spool, plus shipping. Does anyone have a better/less expensive source of 20-22 gauge wire rated at 600V? I'd rather not turn a $35 project into a $100 project, with $40 of wire sitting around that I'm never going to use. I figured Id ask here first before attempting to order 3ft of wire from Bob/Roy.

I'm surprised they don't include a length of wire in the standalone board kits as the retrofit requires additional wire.

https://www.parts-express.com/grip-tools-43111-wire-spool-rack-with-400-ft-of-assorted-wire--365-211

I've got a bunch of 22 gauge stranded wire. I'll send you some if you cover the postage back to me via Paypal. Should only be about $3-4. I'm assuming you're in the continental USA.
Pm me your address. (Let me know what color you want.)

PM Sent. Sorry for the double post. I'm not sure why/how that happened. I'll try to kill the other thread.

Ray

I just cut the wire. Then I looked at it under a magnifying lens and it says 300 volts. No good??

Dave_in_Va wrote:I just cut the wire. Then I looked at it under a magnifying lens and it says 300 volts. No good??

B+ in a 70 is upwards of 475 VDC, which is also much more prone to arcing than AC.

I would caution against it. This, not knowing what, exactly, the TD Board is switching.

Sorry. I guess I bought cheapo wire ;-(

Dave_in_Va wrote:Sorry. I guess I bought cheapo wire ;-(

Few would even check.
Fewer would care.
And that wire will be just fine for very nearly any other purpose. Possibly even for the intended purpose if the actual voltage is compatible.

I got mine via eBay:

Here's an example: https://www.ebay.com/itm/22-AWG-Mil-Spec-Wire-PTFE-Stranded-Silver-Plated-Copper-Assortment-100-ft/273673938890?hash=item3fb83ce7ca:g:~EkAAOSwPGtcQMFV:sc:USPSFirstClass!11225!US!-1:rk:4:pf:0

I haven't used it yet. It's for the AB board install. It was cheap enough that I got the colors to match the wiring diagram.

https://www.ebay.com/itm/10-feet-18-AWG-Silver-Plated-PTFE-Wire-Blue-Solid-1-Strand-SPC-/231729632505?hash=item35f42994f9

i buy LOTS of wire from this seller. top notch. no affiliation.

Jedidiah wrote:https://www.ebay.com/itm/10-feet-18-AWG-Silver-Plated-PTFE-Wire-Blue-Solid-1-Strand-SPC-/231729632505?hash=item35f42994f9

i buy LOTS of wire from this seller. top notch. no affiliation.

I buy from this person as well, very good seller.

cci1492 wrote:

Jedidiah wrote:https://www.ebay.com/itm/10-feet-18-AWG-Silver-Plated-PTFE-Wire-Blue-Solid-1-Strand-SPC-/231729632505?hash=item35f42994f9

i buy LOTS of wire from this seller. top notch. no affiliation.

I buy from this person as well, very good seller.

Not meant to hijack this thread but what do you folks use to strip this wire? Teflon can be tough without the proper tool.

Xuron - 505ST Wire Stripper - stranded wire 12-26 AWG
(amazon)

It takes getting used to for the PTFE, i normally size up on the stripper then rotate the wire in the strippers. This scores the insulation vs the wire.

I also have a Hakko Thermal wire stripper station that i do not use all that often.

BNR_1 wrote:

Not meant to hijack this thread but what do you folks use to strip this wire?  Teflon can be tough without the proper tool.

I use nail clippers and a light touch.

Jedidiah wrote:https://www.ebay.com/itm/10-feet-18-AWG-Silver-Plated-PTFE-Wire-Blue-Solid-1-Strand-SPC-/231729632505?hash=item35f42994f9

i buy LOTS of wire from this seller. top notch. no affiliation.

I’m another fan of this eBay seller.  He also sells great selection of shielded Teflon wire. Teflon makes dealing with soldering shielded wire much easier.


BTW - vizsla, Is your screen name from the dog breed?  I’ve owned 3 V dogs over the years (on second thought, make that 2, one of them owned me truth be told.....)

Here's some more -- I realize you don't want to spend this much, but it doesn't rot (lol) and can be used for lots of stuff -- I wish I had ordered this and wired my whole amp with it:

https://www.ebay.com/itm/100-Ft-20-Awg-Solid-Core-silver-Plated-600V-Teflon-Wire-Audio-Tube-Amplifier/173772895504?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Military surplus wire -- especially anything with silver-plated copper and teflon insulation -- is AWESOME!

Jedidiah wrote:Xuron - 505ST Wire Stripper - stranded wire 12-26 AWG
(amazon)

It takes getting used to for the PTFE, i normally size up on the stripper then rotate the wire in the strippers. This scores the insulation vs the wire.

I also have a Hakko Thermal wire stripper station that i do not use all that often.

One cautionary note:

Vaporizing PTFE to any degree at all is an environmental horror show: https://www.fluoridealert.org/wp-content/pesticides/teflon.effects.lung.htm

Even overheating the stuff in small quantities is acutely toxic to cats and birds.

I don't know what's available in the consumer market, but when I worked at a mil-spec plant, we used a thermal stripper for teflon that would melt it instantly, and cook you well done if you bumped it.

In terms of how much HV wire you need it's not a lot..... The transformer AC secondary wires go directly to the TDR board and then there's only a very short run from there to the rectifier.

All other wiring is at fillament potential.

Look at post 1 of this link https://dynacotubeaudio.forumotion.com/t3752-vta120-all-wired-up-ready-to-bias and you can see what I mean about the wiring lengths.

In my mind the jury is still out on the effectiveness of the TDR board. On one hand you save applying HT to the output tubes until they have warmed up and on the other you are smacking the butt of the rectifier tube by applying HT to it when it too has warmed up and expecting it to instantly charge the filter caps from zero to full working voltage.

But that could form another discussion elsewhere.

bbqjoe wrote:I don't know what's available in the consumer market, but when I worked at a mil-spec plant, we used a thermal stripper for teflon that would melt it instantly, and cook you well done if you bumped it.

You answered your own question - mil-spec plant. The dangers of hot PTFE have been openly know for probably 30 years or more - but the stuff is still sold as a cooking pan coating. Go figure.

That being written, back in the day when I was working as a machinist, we made seals with PTFE O and L rings. The O rings were rippled in a mold at a specified temperature for a specified period of time then plunged in chilled water. Similarly, the L-rings were from flat-stock. But the foreman explaining the process to me was extremely clear that the temperature was not to exceed 350F by the clay-stick method, and the time was not to exceed 15 minutes at that temp. "That stuff'll kill you" was the warning. That was 41 years ago.

This was the same foreman who would give the morning pep-talk followed by, in his best master-sergeant's voice: REMEMBER! You are being paid by the hour, not by the piece!

Sorry, back again. I contacted Roy who sent me a few short lengths of 22AWG 300V stranded saying he's used it for a while and hasn't had any problems. After getting it in the mail, I'm a little nervous to use it for my 440V leads. It looks a lot thinner and more flimsy than the wire that is in the amp right now. Thoughts?

Yep, SN is for the dog breed. I've got one here at home.

vizsla23 wrote:Sorry, back again.  I contacted Roy who sent me a few short lengths of 22AWG 300V stranded saying he's used it for a while and hasn't had any problems.  After getting it in the mail, I'm a little nervous to use it for my 440V leads. It looks a lot thinner and more flimsy than that is in the amp right now. Thoughts?

Yep, SN is for the dog breed.  I've got one here at home.

Edited: Misspoke.

vizsla23 wrote:Sorry, back again.  I contacted Roy who sent me a few short lengths of 22AWG 300V stranded saying he's used it for a while and hasn't had any problems.  After getting it in the mail, I'm a little nervous to use it for my 440V leads. It looks a lot thinner and more flimsy than the wire that is in the amp right now. Thoughts?

Yep, SN is for the dog breed.  I've got one here at home.

Another good supplier is Apexjr.com  I can send you some wire if you have not found any yet. Just let me no what color and if you want stranded or solid. 20AWG PTFE.    I sent you a PM

Thanks! Roy sent some wire. I just haven't installed it yet.

vizsla23 wrote:Thanks!  Roy sent some wire.  I just haven't installed it yet.  

Ok. Thought you were a little nervous using 300 volt wire .  This is 600 volt.