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I pulled some old tubes out of a broken tube radio circa 30's or 40's. The only one that looks usable is a RCA 6V6. Its black metal, not glass. Will this work in an amp, assuming it tests well?

Why not ?

I have a metal tube in my Champ clone for a long time already. It was originally in a Mig 21 fighter from the Indonesian air force.

From a MIG huh. Quite a conversation piece.

mike

How does one come upon a mig fighter jet tube? I'm guessing its a sovtek and that indonesia bought russian fighters back in the 70's or 60's? Either way, thats bad ass. Kudos.

JimD wrote:I pulled some old tubes out of a broken tube radio circa 30's or 40's. The only one that looks usable is a RCA 6V6. Its black metal, not glass. Will this work in an amp, assuming it tests well?

Just so you folks know, metal tubes are still glass inside. Just the outside has metal. You can use a lot of cool tubes including some from old TV sets. Just look them up and see if they're pentodes or tetrodes and get the pinout on them.
Keith

I have read that the metal casing on the tube was for RF Shielding. Some of the metal tubes had the metal casing connected to one or more of the tube pins. I would do some research before plugging these into a socket in a modern amp as they might not be 100% pin compatible.

Freddy wrote:I have read that the metal casing on the tube was for RF Shielding. Some of the metal tubes had the metal casing connected to one or more of the tube pins. I would do some research before plugging these into a socket in a modern amp as they might not be 100% pin compatible.

For instance, you might find the metal casing connected to that "unused" pin you used as a tie-point for your screen supply.

IIRC the original metal tube 6V6s were only rated to 12W max dissipation, rather than the 14W of more recent glass ones.

Please anyone feel free to correct of clarify what I just said....

one of my favorite tube is the metal can 6SJ7 pentode. Sending a guitar signal through that then straight to a 6V6 is near heaven to me. YMMV.

and Phil is right- check the early documentation, because the max dissipation is typically lower then the glass envelope versions.
I've seen early versions of the 6L6 in metal as well.

fun stuff!

J

justinm wrote:one of my favorite tube is the metal can 6SJ7 pentode. Sending a guitar signal through that then straight to a 6V6 is near heaven to me. YMMV.

and Phil is right- check the early documentation, because the max dissipation is typically lower then the glass envelope versions.
I've seen early versions of the 6L6 in metal as well.

fun stuff!

J

Yea, I have some. 6L6 and 6v6.hummm...I think I'll build something around my metal 6L6....maybe single end. Naaa, I better stick with PP, cause I like it here better.

I always wanted to get a couple of those and build a real vintager, like a pre-tweed pro or something, 6L6G's in cathode bias, paraphase pi and a 6SJ7 grid leak preamp.

I have a matched set of metal 6L6's I plan on doing a bassman clone with them


Bill

jckid66 wrote:I have a matched set of metal 6L6's I plan on doing a bassman clone with themBill

Now that's somewhat of a rarity. You mean true matched???Nice. Are they RCA's?

Sorry for the late reply. It is really from an old MIG 21 from the early 60ies which is shown in the Indonesian Military Forces Museum. One tube maniac in Jakarta (he has the biggest collection of NOS tubes I´ve ever seen) managed to acquire this tube and I bought it from him.

And it´s not a Sovtek but it says "RCA 68-48 I 6V6" on it.

Raymund wrote:Sorry for the late reply. It is really from an old MIG 21 from the early 60ies which is shown in the Indonesian Military Forces Museum. One tube maniac in Jakarta (he has the biggest collection of NOS tubes I´ve ever seen) managed to acquire this tube and I bought it from him.

And it´s not a Sovtek but it says "RCA 68-48 I 6V6" on it.

I tried to get some tubes out of 4 F101 Voodoo interceptors that are rotting on the base that I work at. Unfortunately all of the electronics had been pulled out of them. I bet there were a whole bunch of interesting tubes in them at one point. At least I scored big on the simulator that was sitting beside them.

Chappy

zaphod_phil wrote:IIRC the original metal tube 6V6s were only rated to 12W max dissipation, rather than the 14W of more recent glass ones.

Please anyone feel free to correct of clarify what I just said....

Zaphod

I just checked the GE 6V6GT datasheet (circa 1955) and it shows a design centre value of 12W for the plate dissipation.

Another GE datahseet for the 6V6-GTA (circa 1967) gives a design maximum value of 14W for the plate dissipation.

Are these two tubes physically different, or is there a subtle change between the two definintions of 'design centre' and 'design maximum' that allowed them to bump up the plate dissipation rating by 2W?

It would be cool if I could rebias my PP amp to the 14W figure vice the 12W figure.

Chappy

kedsinger wrote:

jckid66 wrote:I have a matched set of metal 6L6's I plan on doing a bassman clone with themBill

Now that's somewhat of a rarity. You mean true matched???Nice. Are they RCA's?

yes they are a matched set of RCA 6L6 I got them a few yrs ago from fleabay and I have not had the opportunity to use them yet... ( life keeps getting in the way LOL!!! )


Bill

Chappy wrote:Are these two tubes physically different, or is there a subtle change between the two definintions of 'design centre' and 'design maximum' that allowed them to bump up the plate dissipation rating by 2W?

I believe that the later production NOS 6V6s got beefed up. Certainly 14W is what I believe most people are using these days.

Are they any good for heavy metal?
Mach II
http://en.wikipedia.org/wiki/Image:FA-1 ... 999%29.jpg

leslie wrote:Are they any good for heavy metal?

Think so, use them in a Fender Champ sometimes with my Flying V.