6L6 tubes

[Chuck H]

Hey! That would make a d*mn big capacitor!

...back on topic: is there enough foil on that tape to really be effective for either shielding or heat transfer?

When I need to do tape shielding and I don't want to wait for an order I go to my local Ace Hardware (but see edit). Most carry a copper foil tape that is just copper and adhesive. It's made for garden slug and snail abatement. It's about 1-1/8" wide and 15' long for ten bucks. Expensive, but 15' actually goes a long way and no waiting. I've noticed too that the adhesive seems to be conductive so this is probably a repurposed product. Fully solder-able with no finish on the copper. Sticks like hell to everything.

EDIT: Damn! I paid too much! Looking for a link I found this:

http://www.homedepot.com/p/Corry-s-1...9017/100662157

Same stuff and there's a Home Depot two blocks from the Ace Hardware here. I like Ace a lot so I guess I don't mind supporting them. Anyway. Now YOU know. Home Depots are usually easy to locate

[Enzo]

Putting aluminum foil on the wood is not to insulate it. The foil acts as a reflector.

[Pdavis68]

In this particular case (the case I brought up), the aluminum isn't acting as the insulator, it's the air between the aluminum and the wood that actually acts as the insulator. The aluminum just shields the air from direct heat and keeps the air isolated so it doesn't flow.

[g1]

I think there are new Tung-sol branded 6L6 tubes available in short bottle.

[eschertron]

Putting aluminum foil on the wood is not to insulate it. The foil acts as a reflector.

In this particular case (the case I brought up), the aluminum isn't acting as the insulator, it's the air between the aluminum and the wood that actually acts as the insulator. The aluminum just shields the air from direct heat and keeps the air isolated so it doesn't flow.

Yes, there's some reflection going on, and there could be an air gap. You're both right. But IMHO the biggest factor involved in reducing temperature rise is conduction. The heat transfer coefficient of aluminum is better than that of wood, so the radiant energy hitting the foil is conducted away from that spot faster with the foil than with the bare wood.

[Enzo]

There are the "baseless" versions like these still being made:
https://www.tubesandmore.com/products/T-5881-SOVT

[Ken Zuercher]

If you haven't found any short 6L6s yet, JJ has issued their take on the 5881. I bought a matched pair and put them in one of my builds. They have the same specs as their longer bottle 6L6s but I'm sure that the inter electrode capacitances are different. The tubes are definitely short enough and sound kind of cool but are different from the 6L6 that I usually use. Get them from our usual source. Is it OK to mention sources on this board?

[Chuck H]

Is it OK to mention sources on this board?

Standard etiquette applies. If you're plugging your own thing we have a space for that. If you're insulting a vendor it'd better be factual info or you might take a beating. Otherwise, yes, we'd like to know where you get your tubes and any advantages they offer.