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Tube replacement help...

Discussion in 'Electronic Repair' started by 30W, Sep 28, 2005.

  1. 30W

    30W Guest

    Hello all,

    I ordered some replacement tubes for an old radio for a friend. All
    the tubes seemed ok except for two. One of them is missing a pin that
    the original had and one has an extra pin that the original did not.

    My question is do these pins matter? Is it possible all the pins are
    not being used?


    Original Tube Replacement Pins
    6BG6GA 6BG6G Extra pin
    35Y4 35Y4 Missing pin

    They are going in a Sears Silvertone Radionet.


    Thanks alot for any info!!

    M. M.
     
  2. Arfa Daily

    Arfa Daily Guest

    The 6BG6 is a beam tetrode. According to my data book, the following pins
    are used

    Pin 2 - heater
    Pin 3 - cathode
    Pin 5 - control grid
    Pin 7 - heater
    Pin 8 - screen grid
    Top cap - anode

    Pins 1, 4 and 6 have no connection / no function

    The 35Y4 is a rectifier with the following pins used

    Pin 1 - heater
    Pin 2 - anode
    Pin 4 - heater tap
    Pin 7 - cathode
    Pin 8 - heater

    Pins 3,5 and 6 have no connection / no function

    It is not at all unusual for these Octal / B8G based tubes to have extra or
    missing zero-function pins between different manufacturers, so you should
    not have a problem.

    Arfa
     
  3. Ken Weitzel

    Ken Weitzel Guest

    Hi M M

    If it's any help at all, my ever shortening memory has me believing
    that the last digit of the type indicates the number of pins actually used.

    Ken
     
  4. Guest

    Ken Weitzel:
    That is an "old wives" tale that I heard in the 60's when I learned
    electronics with tube equipment .... some might believe would specify
    the number of elements in the tube but there are so many, many
    exceptions. On some tubes it works if you count the heater as one
    element, other tubes count it as two elements.... snd still others,
    don't count it at all.... in other words, the rule doesn't work
    reliably.
    electricitym
    ..
    ..
     

  5. is where the tube people hang out.
     
  6. Arfa Daily

    Arfa Daily Guest

    Is where SOME tube people hang out. Not all tube equipment is antique, or
    even vintage. Much is still manufactured now.

    Arfa
     
  7. James Sweet

    James Sweet Guest

    I dunno about "much", sure there's some tube equipment still made but most
    of it is exorbitantly expensive audiophool gear, quite a lot more tube gear
    is vintage.
     
  8. Arfa Daily

    Arfa Daily Guest

    No, I still repair " much " that is currently manufactured and used by
    musicians as PA equipment. Whilst some of it is quite expensive, at least an
    equal amount is very reasonably priced, and certainly on a par with
    similarly rated solid state equipment.

    Some tubed hi fi is very high end price wise - I currently have a Shanling
    SP-80 on the bench, and the price tag on that is for an amount that would
    have bought you a decent secondhand car a few years ago - but there are also
    reasonably priced items around, and tube designs have been making a real
    comeback over the last couple of years in the home constructor market.

    Arfa
     

  9. There is only a fraction of a percent of new tube gear built per
    year, compared to even the late '70s when the tube was well on its way
    out of the mainstream. I'll bet you could stop 100 people on the street
    and not find more than one person with a tube in anything, other than a
    CRT, unless you rigged the survey. People used to have 50 to 100 tubes
    in various pieces of equipment around the house.

    Even high power radio and TV transmitters ate going all solid state.

    BTW, don't try to impress me about vacuum tube musical equipment. I
    serviced it for over 30 years and I know where several Hammond organs,
    and a few Leslie speakers are in use about a half mile from here. I use
    to buy 100 6GH8 tubes at a time for TV repair, and had over 5000 new
    tubes in stock between our two TV shops and five service trucks. I
    repaired a lot of West, Sunn, Fender, and other tube musical amps. I
    have worked with subminiature 1 volt tubes all the way up to 65 KW EEV
    Klystron tubes used in UHF TV transmitters. Those tubes were over
    $45,000 US, each, plus special freight charges.
     
  10. Arfa Daily

    Arfa Daily Guest

    I'm not trying to " impress " you, or anyone else about my abilities. In the
    case of the majority of amateurs who ask questions on here, and whom as a
    professional, I try to help, they probably would be impressed as a matter of
    course, in much the same as that I, being only an amateur carpenter, or
    plumber, or car mechanic, am impressed by the knowledge of people engaged in
    those fields.

    I too have repaired this equipment for some 30 odd years, and, whilst I have
    not worked with tubes bigger than a kW, I have certainly worked with sub
    miniature types - in fact I recently rebuilt a military radio transceiver
    which used them, and didn't have much difficulty obtaining them either. So,
    by the same token that you claim I am trying to impress you, don't try to do
    it back to me.

    The only point I was trying to make, is that there is still a considerable
    amount of vacuum tube equipment being currently manufactured, which many
    amateurs, and probably more than a few professionals don't realise. It is
    NOT all vintage, and tinkered with by ancient proffessor longhairs. Whilst
    there is no longer TV sets and tape recorders being manufactured with tubes
    in - and nobody, amateur or professional needs to be told this - the sector
    of the market producing tube amplifiers is still alive and as well as it
    ever was.

    Fender, Ampeg, Orange, Marshall are all names that immediately spring to
    mind. If you like, I'll check with one of the equipment shops that I do work
    for, and see how he thinks that the market for tube amps is, in comparison
    to 30 years ago.

    I really don't know what has happened to newsgroups in recent years. People
    now seem to treat them as forums, and chime in with all manner of unhelpful
    replies to posters. It used to be that if someone- often an amateur - wanted
    to know something, they posted and asked, and some kindly soul, who knew the
    answer, posted back. The original questioner then either posted back to the
    group, or direct, and said " Thank you for your help. The problem is now
    cured." End of.

    Now, all manner of other posters will chip in with half assed replies, and
    often getting quite nasty saying " Go Google it, and don't be so lazy " and
    other such stuff. This is not helpful to amateurs.
    Recently, a poster on here had asked how to get into a Bose sub. Despite how
    clever all the self styled moderators on here are, it's not at all obvious,
    unless you know. Helpfully, the first reply was " Use a chopsaw ... "

    On many occasions, I have spent hours on the net trying to track down info
    on something, and then posted on an appropriate group, and got an immediate
    answer from a professional in that field.

    I still try to be one of those " professionals in the field " , and try to
    help, constructively, where I can. If people want to be " impressed " by
    that, then so be it, but don't imply that I am actively trying to impress. I
    know my abilities and limitations, and have been around for far too long to
    need to play silly games of how good I am.

    Arfa
     
  11. Asimov

    Asimov Guest

    "Arfa Daily" bravely wrote to "All" (29 Sep 05 08:47:04)
    --- on the heady topic of "Re: Tube replacement help..."

    AD> From: "Arfa Daily" <>
    AD> Xref: core-easynews sci.electronics.repair:343445
    [,,,]
    AD> I really don't know what has happened to newsgroups in recent years.
    AD> People now seem to treat them as forums, and chime in with all manner
    AD> of unhelpful replies to posters. It used to be that if someone- often
    AD> an amateur - wanted to know something, they posted and asked, and some
    AD> kindly soul, who knew the answer, posted back. The original questioner
    AD> then either posted back to the group, or direct, and said " Thank you
    AD> for your help. The problem is now cured." End of.

    AD> Now, all manner of other posters will chip in with half assed replies,
    AD> and often getting quite nasty saying " Go Google it, and don't be so
    AD> lazy " and other such stuff. This is not helpful to amateurs.
    AD> Recently, a poster on here had asked how to get into a Bose sub.
    AD> Despite how clever all the self styled moderators on here are, it's
    AD> not at all obvious, unless you know. Helpfully, the first reply was "
    AD> Use a chopsaw ... "
    AD> On many occasions, I have spent hours on the net trying to track down
    AD> info on something, and then posted on an appropriate group, and got an
    AD> immediate answer from a professional in that field.

    AD> I still try to be one of those " professionals in the field " , and
    AD> try to help, constructively, where I can. If people want to be "
    AD> impressed " by that, then so be it, but don't imply that I am actively
    AD> trying to impress. I know my abilities and limitations, and have been
    AD> around for far too long to need to play silly games of how good I am.
    [,,,]

    Arfa,

    This newsgroup has always been a little bit schizoid because it has a
    dual vocation depending on who you ask here. In this group co-exists
    two types of techs, one is the knowledgeable amateur, and the other is
    the mercantile professional. We all engage in exchanging information
    about various electronics and are occasionally interrupted by the odd
    consumer who asks things like "I changed the fuse 5 times and it still
    doesn't work". Naturally the commercial pro will tell them to bring
    their gadget to a shop and so will the amateur at some point. The
    difference between them is the amateur will try to guide the USER
    somewhat. I understand the pro in their telling the user anything is a
    waste of time but then the sci. prefix in this group would be
    meaningless. I learn a lot from the pro and I've set a few straight on
    occasion so I feel our schizoid relationship works quite well in
    retrospect.

    A*s*i*m*o*v

    .... Professionals built the Titanic, amateurs built Noah's Ark
     

  12. Bull. At one time EVERY home Hi Fi or stereo was all tube. Today
    only a small fraction of a percent are ewither built new, or are still
    in use.

    Please do. While you're at it, make sure to check with all the
    others who are out of the tube amplifer business because there isn't
    enough work to support more than one shop in any one area. There is
    exactly ONE shop in the Ocala area that still works on tube amps,
    although its only a tiny part of his repair work. All the music stores
    send him their equipment to repair, but 30 years ago, most had their own
    repair departments.


    You put down my suggestion of the OP going to a newsgroup centered on
    tube based equipment. I tell some people who post there that they
    belong here, even though they might find help on the other newsgroup.
    Why limit your chances by not going to where you can find more help?


    Some are too lasy to use any search engine. If I read, "I've looked
    all over the place and can't find anything about..." and find it as the
    first hit with a search engine what do you suggest?

    1: Lead them step by step so they never learn anything?

    2: Totally ignore them, plonk them, and then forget they ever posted.

    3: Tell them to take another look, with the proper search term.

    I prefer # 3, but you can do whatever works for you.

    Sorry, there are no "Moderators" on this group. Never have been, and
    never will. This was not chartered as a moderated newsgroup.


    If all else fails, try a little humor. Any day you can't laugh
    wasn't worth getting out of bed.

    Once again, I suggested an appropriate newsgroup and you slammed the
    idea.

    I have been a "Professional" in many electronic fields in the last
    40+ years. I started with TV repair at 13 by working part time, then
    full time after I graduated. There were over 50 TV shops in my home
    town, but only a couple had the reputation, "Those guys can fix
    ANYTHING!" I managed two of them and ran the commercail sound
    departments in both of them. Then I went into the military where I was
    awarded the MOS for broadcast engineer, after testing out of a three
    year elctronics school. After my time in the service, I opened my own
    commercial sound business, added industrial equipment, then computers
    and industrial video
    equipment. I ran a service center in Cincinnati, Ohio for United Video
    where we repaired and modified CATV headend and distribution equipment.
    After that I moved to Florida to work as a broadcast engineer at a 5 MW
    EIRP UHF TV station in Orlando / Orange City. After that, I moved and
    rebuilt an all tube RCA TV transmitter to but Ch 58 in Destin, Florida
    on the air. My last job was building telemetery equipment at Microdyne
    (bought out by L-3com). Some of my work is in space, and the weather
    satellite photos you see on the news come through Microdyne 700 series,
    or a turnkey 'MFR' packaged system built here, in Ocala. In other
    words, I have been all over the industry, as it changed. These days, I
    repair computers for free, and give them to disabled veterans but I
    still have a 1200 square foot shop here at home that has equipment
    ranging from early tubes, to VLSI SMD construction.


    BTW, the last time I checked, all 50+ TV shops in my home town are
    long gone.
     
  13. Arfa Daily

    Arfa Daily Guest

    Yeah OK - whatever. We're all jolly impressed now with your wonderful
    career, but you know what ? I reeeeeally can't be bothered to waste the time
    addressing all the endless new points you make. So good. You win. Big NG
    result for you. I won't waste any more of your clearly valuable time . You
    can spend it hunting gators or playing with your swamp boat or whatever it's
    called. ( that's humour ).

    Have nice day

    Arfa
     

  14. Sorry, but there are no gators in Marion county, and very few air
    boats in this part of the state. That is in other parts of the state.
    You must be thinking of south Florida. You might try Google to learn
    more about gators and airboats :)

    BTW, most of the guys with air boats are still up in the Gulf where
    they went to help rescue people after the hurricanes, and that is no
    joke.
     
  15. Arfa Daily

    Arfa Daily Guest

    Oh Boy, you just can't leave it, can you ? You see, whilst you may have had
    a long and distinguished career in electronics, it certainly didn't include
    an in depth understanding of the subleties of the queen's English, did it ?

    I did not " slam " your suggestion of the OP going to the tubes group, I
    merely made an observation that only ' some ' tube people hang out there,
    and it seems to be mostly old stuff that they are discussing ( hence the "
    antique " in the group name). At the original point of this poster needing
    an answer, that MAY have been an appropriate place for him to ask, but I was
    trying to make the point that where he HAD asked, there was just as likely
    to be people who had sufficient experience of vacuum tube technology, to be
    able to answer him. Indeed, I was able to answer his question, in full, and
    on here, where he posted. In fact, this emphasises the point that I was
    making about everyone having to stick their oar in these days. There was no
    need for you, or indeed anyone else, to add anything else to what I had
    already replied to the OP - unless you thought that something I had said was
    wrong. The OP asked a SIMPLE question, which required a SIMPLE answer. I
    just happened to be the first one to give it. If you had to point out the
    tube group, you could have said something like " There' a group at
    news.rec.antiques blah blah where many more tube people than here, hang out
    ", but no, you had to post it as a curt abrupt link as though the guy should
    hang his head and go there, rather than to have been dumb enough to have
    asked on a general electronics service group.

    This also emphasises the point I was trying to make, but was clearly too
    subtle for your ears, about moderators. I know that the group is not a
    chartered, moderated one but, like lots of other similarly non-chartered
    groups, it has many self opinionated and pompous know-it-alls, who feel that
    they've got to comment about anything that they see, and add their 10 cents'
    worth. If the group WERE a moderated forum, these are the people who would
    be clamouring for the jobs. As it's not, they do the next best thing, and
    start these endless and stupid thread-extension arguments. What they would
    really like to do, if they were a real moderator, on a forum where you CAN
    have editorial control over what appears, is ' kill ' the poster, but
    they're not, so can't. Hence the reason that I called these people "
    self-styled ", and make the point of some people trying to treat the groups
    as forums ... Still with me ?

    I wasn't going to bother to reply to your last comments, but some are so
    silly that I think I really must. When I said that the tube amp market was
    still alive and well, we had already moved on to musician amplifiers. Anyone
    with two brain cells knows that hi fi's are no longer predominantly
    manufactured with tube technology. In fact, I would have to question whether
    it was ever the case for stereo reproduction. By the time stereophonic
    source material had really taken over from monaural, most reproduction
    equipment had already moved to semiconductors.

    As far as there not being many music shops now that repair their own
    equipment, this is, I think, more to do with there being a lack of skilled
    technicians in electronic service branches now, and the modern business
    model that dictates that it's financially more appropriate to outsource
    specialist services, than to try to provide them yourself. This has come
    about due to the throw away Japanese import society that we now live in. The
    point that I was trying to make about tubed equipment, and that you
    deliberately or otherwise seem to be missing, is that there is still a
    market out there, that the major players, such as those that I suggested
    before, consider healthy enough to continue producing equipment for,
    alongside their contemporary solid state ranges. As an aside, modern
    manufacturing and circuitry design techniques dictate that the equipment is
    also much more reliable than it used to be, so you really shouldn't equate a
    lack of quantity for repair, as being a lack of quantity being sold.

    Today, I telephoned a local musical instrument shop that I do work for, and
    asked the owner what proportion of the amplification that he stocks, is tube
    based. His reply was - at least 70%.

    Surprised ?

    I then went on to ask him how healthy the market for this gear is, compared
    to say 30 years ago. He said that the bedroom guitarist market is now at
    least as big, if not bigger than it was back then, and that in his (
    considerable and lengthy ) experience, ALL serious guitarists aspire to
    owning a tube based amplifier. The remaining 30% of his stock, he says, is
    mainly at the lower end, and bought for practice purposes, or if higher end,
    used for vocals or keyboards. Now I'm sure you're going to have an opinion
    on that, but to me, it indicates that you're either out of touch with this
    market, or that there's not a lot of musical talent in your neck of the
    woods. You can't dispute what a person who owns a large shop in that
    industry, says.

    Likewise, I have to respect what you say about gators and airboats - you
    live there, but I've only ever been as a visitor, and of course, the
    disaster in the Gulf is not a joke, and I did not imply in any way that it
    was ( or even mention it ). I was merely being facetious to try to inject a
    little humour, local to your geographical area, into what had become a
    rather edgy interchange.

    So far, I think I've been pretty polite, against the increasing level of
    vitriol that I have been receiving back, but if you want nasty, I can do
    nasty. Personally, I believe that I'm bigger than that, but the question is,
    are you ? Judging by the fact that you have been in the electronics business
    for more than 40 years, I guess that this must put you in your sixties. So
    please, grow up and act your age, and stop trying to get the last word. This
    nonsense serves no useful purpose. Now, I really do have no more to say on
    the matter, and if you're big enough to do the same, we'll call it a draw,
    and stop wasting both our time, and the time of the people following this.

    Agreed ;-) ??

    Arfa
     
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