Discussion in '"Boat Anchor" & Classic Equipment' started by W3RU, Oct 16, 2020.

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  1. W3RU

    W3RU Ham Member QRZ Page

    Continuing my on-going quest to come up with a reasonably priced substitute for the overpriced, now- audiophool 6GW8 audio output tube used in the HW and SB-10x transceivers, I ran across this listing on our favorite auction site:


    Has anyone purchased one of these, and tested it using the 6BM8 tube it supposedly is re- wired for? Did it require any under-chassis rewiring or resistor replacements to make this tube work properly?


    Jack W3RU
    W1BR likes this.
  2. KP4SX

    KP4SX Premium Subscriber QRZ Page

    That gadget is $8.50 ( Does not ship to Puerto Rico) so I don't know about shipping. And you have to buy a tube.
    You can get a 6GW8 for $6/used - $12/new.
  3. W1BR

    W1BR Premium Subscriber QRZ Page

  4. W5RKL

    W5RKL Ham Member QRZ Page

    The adapter ad doesn't provide dimensions, how tall it is when fully seated into
    a tube socket as measured from the bottom to the top of the adapter.

    The 6GW8 and 6BM8 tubes are the same "seated" height, 2 13/16" (see
    tube data sheets).

    V14's tube socket does not sit "flush" with the top of the audio PC board.
    From the top of the PC board to the top of the tube socket is 1/4" or 4/16".

    With either tube sitting flush in V14's tube socket, the top "tip" of the tube to
    the inside bottom cover is 1 7/16". Add the 1/4" to 1 7/16, and
    the overall approx height from the top of the PC board to the top of the tube's
    tip is now 1 11/16". Add the height of the adaptor, could result in the top tip
    of the tube extended beyond the inside bottom of the top covers.

    I would write the eBay seller and ask for the "seated" dimension of the adaptor.
    Seated dimensions are from the bottom of the adaptor when plugged flush into
    a tube socket to the top of the adaptor. With the seated dimension you can
    determine with the tube seated in the adaptor and the adaptor seated flush in
    V14's socket, whether the top covers can be installed/closed or not.

    Mike W5RKL
  5. KI4ZNV

    KI4ZNV Ham Member QRZ Page

    These aren't the same tube and they won't bias at the same points. The pentode section will be more different than the triode section. And the replacement won't be able to sink anywhere near as much power if that's an important concern...the original 6BM8 was designed as a vertical sweep tube for a TV set and the power pentode will put out 3.5 watts. So I guess it depends on the application, but I don't see any reason to do this sub when the 6BM8 is not that expensive an item and is a tube that is not likely to fail often.
  6. W3RU

    W3RU Ham Member QRZ Page

    The 6GW8 is the expensive tube we would like to replace, not the 6BM8.

    Jack W3RU
  7. KP4SX

    KP4SX Premium Subscriber QRZ Page

    What do you consider "expensive"?
  8. W9BRD

    W9BRD Ham Member QRZ Page

    If you're willing to do some socket rewiring, a 6GV8 is another sorta-replacement possibility.
  9. W3RU

    W3RU Ham Member QRZ Page

    Any tube in the 6C10 and 12AX7 cost category, or over $5.00 used.

    Jack W3RU
  10. KP4SX

    KP4SX Premium Subscriber QRZ Page

    So you'd buy an $8 adapter + an unknown performing tube rather than an original $6 tube? Weird! :eek:

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