Wire for tubes using a plate cap?

[kstagger]

For my 1625 SE amplifier, I'm running some 425VDC above the chassis. For now there is just some 20awg solid-core wire being used. However, I don't think this is a very safe option, especially with the thin insulation and the chance that repeated bending, etc could cause the wire to break.

Normally for my own use, I wouldn't be so concerned, but I have a friend who is interested in buying this amplifier. I'm also planning on replacing the Chinese ceramic top caps with something NOS.

My other option - on-hand - is to use some shielded cable that has a PVC jacket and foil underneath that. The two conductors inside are only 22awg so I do have some fear of this thin multi-strand wire being eventually bent enough to break. This is the wire I'm using for the grid-cap of the 12J7 and it seems to work just fine.

Thoughts?

 

[TheGimp]

Rubber Insulated High Voltage wire is rated for 30KV. It is what I would use.

150°C (302°F) High Voltage 5KVDC to 50KVDC Lead Wire on Thermal Wire & Cable Corp.

 

[kstagger]

ah - that's what I'm looking for - something with a thick jacket. thanks!

 

[20to20]

Meter lead wire. Usually rated for 2Kv. Get some cheap replacement meter leads and cut the ends off. Get one of those free meters with any purchase with coupon at HF.

 

[Vinylsavor]

Hi!

I usually use a thin solid core wire which has an insulation which is suffciently rated for the voltage at use. I pull this then through an additional insulation sleeve. For example the insulation stripped form a thicker solid core copper wire.

Best regards

Thomas

 

[CarlyBoy]

How 'bout PTFE?

I don't know what temperature it's rated for but rubber has got to be among the lowest of the insulating materials used for wire. This in combination with it's floppy nature is something I don't want in close proximity to power tubes. I recently purchased some MIL spec PTFE (Teflon) wire from Apex Jr. rated at 1000V. In the interest of stiffness I went with 12 awg, but you could go all the way down to 8 awg if you wanted. I'm not interested in transmitting tubes so I'm rarely over 500V and never over 600V so I'm confident this wire will be sufficient for my needs.

 

[roline]

I've been using the thick silicone insulated stranded core for a couple yrs and it is still like new. No problems to report....

 

[20to20]

0 ohm racing plug wire. Good for 40Kv and available in your favorite colors.

 

[Shoog]

I used salvaged Multimeter probe wire. Cheap and available (all those dead meters) and designed to be flexible and durable.

Shoog

 

[HollowState]

Belden type 8899 test probe wire. It's flexible, stranded and rated at 5KV. No reason to use anything rated for higher voltage unless you just happen to already have it.

 

[enzoastro]

I use 20kv 200 deg c rated stuff off e bay, seems ok.

enzo

 

[Palustris]

From: Kimber customer support

The voltage rating for the TCSS is 10k. The actual model number of the wire is 10kTCSS.

>To: Kimber customer support
> Please provide the voltage rating for the TCSS/19 wire. I would like
> to use it in an audio amplifier with a B+ supply of 1250VDC. I can use it
> with a teflon sleeve if required.
>

 

[bear]

I'd not use rubber or PVC, since it degrades over time.

Test lead wire will crack and develop pin hole defects too... the asian stuff is especially not so good.

I prefer suitable insulated wire with a suitable (usually, but not always) PTFE spaghetti sleeve over that. More reliable, imo.

_-_-

 

[scott17]

Once the circuit is built and in place why would the plate cap wire ever move enough to be of concern?

Just slide a length of 600V or greater heat shrink tubing over it, shrink it, and call it a day.