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HP 214B Pulse Generator repair question

Discussion in 'Electronic Repair' started by Richard Rasker, Sep 6, 2010.

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  1. Hello,

    I've been asked to fix a special piece of lab equipment, a Hewlett-Packard
    214B Pulse Generator, dating back from 1980 or thereabouts.

    The problem is relatively straightforward: a chain of components in
    the -155V supply has blown:
    * PCB fuse F602, value unknown
    * Q601 and Q602 (MJ15003)

    Since the fuse (F602) has literally exploded, there's no way to determine
    its original current rating.

    The question of course is what caused this rather convincing supply failure;
    the main suspects here are the output tubes V401 and V402-- but I can't see
    what types these are either. I have a schematic diagram, but no part list,
    so I'm rather stuck.

    Does anyone have any experience with these beasties? Or could someone point
    me to a service company which may perhaps provide the information on the
    fuse and the tubes? AFAICT, it's still a rather expensive piece of
    equipment (~$ 6,000), so I really want to try and repair it.

    Thanks in advance for any information,

    Best regards,

    Richard Rasker
  2. [snip Hewlett-Packard 214B Pulse Generator]
    Thank you for your swift reply -- but unfortunately, that sites offers the
    exact same diagram/manual file I already have. The trouble is that there's
    no parts list included, so I can't look up any component values.

    So any suggestions are still appreciated :)

    Best regards,

    Richard Rasker
  3. Great find, but once again, it doesn't feature a parts list that I can find;
    the text also doesn't mention the type or ratings of output tubes or fuse.

    I'm afraid that all manuals available on the Internet are based on this
    one -- they're eerily alike, especially the front page photo scan is
    identical in all cases. I'll try contacting Agilent, but something tells me
    that this may well be the only information they have available,
    so the outlook isn't particularly favourable :-(

    Anyway, thank you for your efforts (mr. Terrell as well).

    Richard Rasker
  4. Bob Pownall

    Bob Pownall Guest

    On 9/6/2010 7:57 AM, Richard Rasker wrote:
    I used to work at HP. I'll post to an HP alumni technical list and see
    if anybody who used to design / build / support these things responds.

    Bob Pownall
  5. Meat Plow

    Meat Plow Guest

    I've repaired some old SW radio gear where it was impossible to get
    technical data. That never stopped me though. I understood the circuits,
    mixers, IF, Hartley osc etc.. and applied what I knew typical values
    existed for the circuit to work. Similar to what you suggest. Same with
    more recent mosfet power amp from the 80's. Sound Code Systems or SCS.
    Couldn't find at the time (too early for the primitive internet search
    engines) any service errata. But I knew the parameters of the devices
    and what they should spec and effected a repair. The amp is still in
    service here. If the OP has a couple blown MJ's and a toasted fuse that
    shouldn't require scientific intervention.
  6. Archon

    Archon Guest

    Artekmedia have the full manual, I guess you can get it as download off
    their website if you contact tthem, ( ) but its listed
    as a CD on Ebay , search # 370162101455

  7. I'm legally responsible for whatever goes wrong (further damage or injury)
    if I put in the wrong parts, most notably fuses. Furthermore, this thing is
    used in a university laboratory by quite a number of people, so I really
    need to get it right. So in this particular case, guesswork is out of the
    question (but if I had to guess, I'd say that the fuse should be something
    between 1 and 4 amps, and the tubes look quite similar to PL519's).

    Richard Rasker
  8. Meat Plow

    Meat Plow Guest

    This guy just doesn't seem to get it. I could see if he was working on a
    GE MRI machine or Agilent DNA spectrometer. But this is an obsolete pulse
    generator from the 80's. Besides repair is he also legally responsible
    for calibration and certification?
  9. Bob Pownall

    Bob Pownall Guest

    OK, I got some responses but I'm not sure how useful they are.
    is an eBay listing for the HP 214B Operating and Service Manual. It
    claims to be 147 pages, and thus more complete than the 123 page manual
    available for download from the Agilent website:

    The eBay price is $7.50 + $2.25 shipping, so how far wrong could you go?
    is a PDF of the 214B repair & maintenance manual. Again, at $2.99 +
    $1.99 shipping, how far wrong could you go?
    is a dead 214B that could maybe be used for parts.

    Sorry I couldn't come up with better answers to your questions.

    Bob Pownall
  10. OK, thanks, I think I'll give this one a go. The equipment is definitely
    worth it, and besides, half an hour of my time is rather more expensive
    than this.

    Richard Rasker
  11. OK, thanks for the tip , but I just ordered the manual -- and it did indeed
    contain the parts list. I hope to get to work on it next week. And oh, the
    fuse was 3 amps slow, and the end tubes were 7534 (E130L, nothing like the
    PL519 at all).

    So in all, I got the information I needed, and now I just hope that I won't
    need to hunt down new end tubes ...

    Anyway, thanks again, best regards,

    Richard Rasker
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