tube identification help ,please

Discussion in 'Glowing Bottle Tube Amp Forum' started by 24 track, Oct 21, 2021.

  1. 24 track

    24 track Doctor of Teleocity Ad Free Member

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    I was going through my used tubes today looking to see if I had a a spare 6V6 in inthe box ,I did alls good there
    but I came across some tubes that I am not familiar with
    A) RCA (electron) 0B2, 7 pins ( the size of a 12AX/AT 7)
    B) RCA 884, 6 pins staggered
    C) Stark 6sn7 GTB 8 pins full pins

    thanks in advance to you tube gurus, there is much more I need to learn
     
  2. SnidelyWhiplash

    SnidelyWhiplash Friend of Leo's

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    Pics are a must... :)
     
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  3. tubedude

    tubedude Tele-Holic Silver Supporter

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    The 6SN7 is a dual triode. Nice tube, I use them in every build. 884 is a thyratron, used in radar systems. The other I think is a voltage regulator or rectifier, not sure.
     
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  4. 24 track

    24 track Doctor of Teleocity Ad Free Member

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    thank you I had a box of tubes and opened it up there must be about 20 ,6sn7 'in it all are in great shape

    I also found I'm not sure about
    6SC7
    6SK7
    50L6GT

    (of course these were with a plethora of 6V6 , 6L6 , ecc83/12AX7 /AT7, 5U4,etc ) but these I know
    thank you for your responce!
     
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  5. AlfaNovember

    AlfaNovember TDPRI Member

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    0B2 is a voltage regulator. 105 volts. It's filled with a mixture of gasses that begin to conduct at a certain voltage, so it provides a stable-ish voltage reference which can be used in a circuit to hold the B+ voltage at a certain point. It also lights up a pretty color, like a tiny neon sign.

    https://www.radiomuseum.org/tubes/tube_0b2.html
    Edit Post by AlfaNovember


    Edit: Some of your other tubes:

    6SN7 is ancestor to 12AT7, approximately. Medium gain, two triodes. Useful for guitar.

    6SC7 is ancestor of the 12AY7, approx. High gain, two triodes. Useful for guitar.

    6SK7 is a 'variable mu pentode' - Mostly for radios, not much guitar use.

    50L6 is a 6L6 but needs 50 volts to light up, instead of 6.3v.

    Your tubes won't generally drop into commercial amps, but could be built into something DIY.

    Edit Edit:

    Looks like you're in the money if you happen to own a 5C4 Tweed Super:

    http://www.thevintagesound.com/ffg/schem/super_5c4_schem.gif
     
    Last edited: Oct 21, 2021
  6. archetype

    archetype Fiend of Leo's Ad Free Member

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    OB2 is a voltage regulator. Also called a "voltage stabilizer" back when circuits were designed for it.
     
    Last edited: Oct 22, 2021
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  7. 24 track

    24 track Doctor of Teleocity Ad Free Member

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    so cool evey one, thank you , I have a lot to learn here
     
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  8. Telekarster

    Telekarster Friend of Leo's Gold Supporter

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    Right on man. A few months ago I asked about tubes as well cause I've got 3 med size boxes full of em, from my Dad when he passed. He pulled tubes out of anything he could get his hands on, going back to the 50's. They nearly got tossed in the dumpster before I rescued em. I'm going to be going through em soon and fig out just what all I have, test em, and go from there. The folks out here helped me ID some of em and gave me good advice! Great!!!
     
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  9. 24 track

    24 track Doctor of Teleocity Ad Free Member

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    that is the magic of this site is the wealth of knowledge and expirience from the members , never ceases to amaze me, truthfully!
     
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  10. lowatter

    lowatter Tele-Holic

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    Not to deter to another site but Hoffman forums also have a lot of folks more than willing to help with challenges such as these. They helped me tremendously transposing a 1974X(ish) build to incorporate a tagboard and use the tremolo circuit as an extra gain stage. Once I got there they helped me add a "Hot" switch which took the amp to a whole other level. You gotta try one of these.
    [​IMG]
    [​IMG]
     
    Last edited: Oct 22, 2021
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  11. 24 track

    24 track Doctor of Teleocity Ad Free Member

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    any and all advise is welcome thank you!
     
  12. tubedude

    tubedude Tele-Holic Silver Supporter

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  13. NTC

    NTC Tele-Holic

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    By the way, a 50L6 IS an audio amplifier tube with a 50 V filament, but it is only good for about 2 to 4W output. They were the power tube for many radios. They are NOT a 6L6 with a different heater. A 25L6 is similar to a 50L6. A 35L6 is an even lower power tube and is not similar.
     
  14. Wally

    Wally Telefied Ad Free Member

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    Tube Data Sheet Locaor
     
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  15. Ignatius

    Ignatius Friend of Leo's

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    I also need some help with a tube identification. I think the person I got this from told me it was an RCA 12ax7. It was a while ago. Just came across it in my stuff and it wasn't labeled (which I'm about to remedy as soon as I find out what it is!).

    IMG_0647.jpeg IMG_0648.jpeg IMG_0649.jpeg Any assistance is appreciated!
     
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  16. Telekarster

    Telekarster Friend of Leo's Gold Supporter

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    I'm a bit confused with your post. Looks to me like it says it's a 12AX7 right on it, and also a brand name (though I can't read the name). Are you asking what it's used for, or? If that's the case, it's a very popular tube used in many, many amps. It's a pre-amp tube. The brand name doesn't say RCA on it as far as I can see, but that doesn't necessarily mean it isn't. However, I don't know how one can tell? If it is RCA, my understanding is that they are very good tubes. If it's still good (need to test it), it would be a nice 12AX7 for an amp. FWIW.
     
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  17. Ignatius

    Ignatius Friend of Leo's

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    Ha - I should have been more clear I guess, and I can see why my post may have been confusing (not enough coffee today yet maybe). It's pretty obviously a 12AX7 and I'm well aware what they are used for :D. I was looking for confirmation that it is an RCA by some our resident tube experts. Based on my fuzzy recollection, I think it's an RCA black plate, or so I think I was told by the person I got it from, but I was hoping to get that confirmation here as well as any other specifics an expert might be able to pass along (era/age, anything about its construction, etc).
     
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  18. Paulie Walnuts

    Paulie Walnuts Tele-Meister

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    Yes its an RCA black plate
     
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  19. uriah1

    uriah1 Telefied Gold Supporter

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    and it is also a "long plate", which I think
    sound better than "short plate"
     
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  20. blues

    blues Tele-Holic Silver Supporter

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    What makes everyone think it's an RCA? I can't tell what the spacers look like from those pictures. Thanks


    I'm not saying it is not,I'm curious is all.
     
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