What the heck is this "vacuum tube"?!?

mhardy6647mhardy6647 Posts: 22,944
If, indeed, a vacuum tube it be... ;)

OK, it was a stormy night last night.
I was goin' though a box of plinkers from my father's shop.
Typical box of old TV tubes; nothin' very interesting.

Except -- this one thing.

My first thought -- a delay relay "tube" or a display tube of some sort... but, the internals look more like a vacuum tube, albeit a tube that someone put together sideways --
like a ship in a bottle?! :p

There is a number printed on it, but it's illegible. It looked like "6JV8" -- but it ain't a 6JV8.

47448100891_b96f978184_h.jpgDSC_4222 (2) by Mark Hardy, on Flickr

40482233823_17a6e281cb_h.jpgDSC_4224 (2) by Mark Hardy, on Flickr

Any of youse mugs have any idea what this thing is?

40482233973_e0e68d64f9_h.jpgDSC_4221 (2) by Mark Hardy, on Flickr

47448100781_1305dbd9e0_h.jpgDSC_4225 (2) by Mark Hardy, on Flickr




  • rpf65rpf65 Posts: 2,053
    A power cell to Flash Gordon’s ray gun?
  • tonyp063tonyp063 Posts: 673
    Something akin to an EMM803?

    One of the "display patterns" variants listed here?
  • mhardy6647mhardy6647 Posts: 22,944
    tonyp063 wrote: »
    Something akin to an EMM803?

    One of the "display patterns" variants listed here?

    That is a very reasonable surmise, although -- if it has a phosphor screen for the electrons to light up -- I don't see it :|
    I will peruse the Magic Eye tube site, though; great idea!
  • mhardy6647mhardy6647 Posts: 22,944
    Turns out, it's a 6JU8; quad diode used in chroma circuits in early 1960s era RCA (and, perhaps other) 21" round CRT TVs. Thanks to "Paulbottlehead" at www.hifihaven.org who recognized the sucka.


    The 6JU8 looked much more "normal" inside (?!).
    (maybe I should've used an interrobang?!)


    What a weird vacuum tube (from the perspective of hifi vacuum tube nuts, that is).

  • heiney9heiney9 Posts: 24,112
    Here's another odd looking one.




    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • mhardy6647mhardy6647 Posts: 22,944
    edited March 30
    Reminds me of a good ol' CRT color TV horizontal output tube/"sweep tube" (also popular with hams, CBers and high-power vacuum tube hifi) like a 6JE6/6LQ6. Lotsa power cheap.

    (borrowed image)

    McIntosh,e.g., used (EDIT) sweep tubes to good effect at one time :)

    innards of an MC-3500 monoblock :) -- not mine, needless to say :/
    Post edited by mhardy6647 on
  • SCompRacerSCompRacer Posts: 7,164
    edited March 31
    McAlister used TV tubes in his amps.

    Make yourself necessary to someone. Ralph Waldo Emerson

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  • mhardy6647mhardy6647 Posts: 22,944
    edited March 31
    SCompRacer wrote: »
    McAlister used TV tubes in his amps.


    Lots o' folks have, over the years!
    ... and, to some extent, vice versa.
    The venerable 6SN7 dual triode was widely used in very early consumer televisions like the RCA 630TS
    source: https://antiqueradio.org/RCA630TSTelevision.htm

    As but a single example of TV tubes in hifi :) -- Doc Bottlehead's "S*E*X" amp kits use(d) various old TV dual triodes to good effect to enable simple, inexpensive single ended triode (SET) "flea power" amplifiers for high-sensitivity loudspeakers. The current version uses the 6FJ7, which is a late-model "Compactron" envelope tube (12 pin "Duodecar" base).



    Plenty of interesting -- and often inexpensive -- TV tubes for hifi :) Unfortunately, the sweep tubes have gotten to be relatively expensive, as supplies have dwindled and demand has continued for them due to their use in various flavors of high-powered amplifiers.

    As always, "chance favors the prepared mind". :) A good set of tube data manuals (readily available from Pete Millett's wonderful site, http://www.tubebooks.org/tube_data.htm ) can help identify opportunities.

    Some of the tubes with nutty filament voltages (designed for low-priced, series-string, power transformerless "killer" sets) are (still) "sleepers" for those willing to work out filament supplies for 'em. B)

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