Connect with us

Returning to valve equipment for greater reliability?

Discussion in 'Electronic Repair' started by N_Cook, May 31, 2013.

Scroll to continue with content
  1. N_Cook

    N_Cook Guest

    A correspondent in NSW, Australia says
    "we live in a damp climate & solid state devices die prematurely"
    tired of dying and burning-up modern kit like oscillioscopes with no
    schematics or parts or knowledge to keep repairing them , they are making an
    active change to resucitating and maintaining valve equipment.
    So what is going on in the likes of NSW, I would have though dampness and
    the high voltage of valve kit would be more likely to failure. Or is it
    just that the information and parts is out there for such repair .
    Or is another route the construction of a sealed cabin with air supply
    passed through a dehumidifier, a more sensible way of dealing with the
    problem and retaining modern kit.
     
  2. Guest

    The OP story doesn't make much sense, unless he/she buys orphan
    equipment that is very vulnerable. I have used Tektronix and HP/
    Agilent oscilloscopes and spectrum analyzers and other electronic
    equipment since the late 1950's in all sorts of climates and never had
    problems like the OP quoted.
     
  3. Guest

    Been there, done that, in the 1950's. With climate change I don't
    think things are getting any better<g>.
     
  4. Phil Allison

    Phil Allison Guest

    "Nutcase Kook"
    ** Read the above properly - it says two things:

    1. The "correspondent" lives in very damp part of NSW - there are a
    tropical rainforest areas in the north of the state.

    2. SS equipment dies due to high levels of moisture - which is correct.

    Almost anything left around in a very damp environment will acquire a flim
    of water - so needing drying out before use.

    Valve equipment left on 24/7 would avoid the problem - which makes the
    valve life rather short.

    Air conditioning the equipment room is the obvious solution.

    BTW:

    Will NK ever wake up what a jerkoff he is ?



    ..... Phil
     
  5. N_Cook

    N_Cook Guest

    It seems an equivalent to trying to use equipment stored in sheds in the
    otherwise more equable climate of the UK.
    Corossion of switch contacts, mould growth from condensation and
    consequential extraneous partially conductive tracks. Older equipment had
    more resilient contacts materials and generally bigger dimensions, seems to
    make them more reliable in such situations
     
  6. Valve equipment becomes thoroughly warmed and is usually designed to
    have a good air flow through the casing; this will dry it out and
    prevent tracking and corrosion if it is used regularly.

    Because high voltages are involved, good valve equipment is designed
    with long tracking distances and good insulating materials (big
    tagboards and ceramic or P.T.F.E. standoffs). Transformers on good
    valve equipment are usually potted or oil-filled. Cheap valve equipment
    with open transformers, printed circuits and small track clearances is
    just as vulnerable to tracking and corrosion as modern transistor
    equipment.

    Fully-sealed transistor equipment should, in theory, be just as reliable
    as good valve equipment; but if the sealing is the slightest bit
    imperfect, the wet will get in and stay in, causing worse conditions
    than if it wasn't sealed at all. This sort of kit will then be less
    liable to recover than the equivalent valve kit because it will never
    warm up enough to dry out. A small contact heater would be one possible
    answer; it could operate permanently, so as to keep the casing a few
    degrees above ambient and help to prevent further condensation.
     
  7. Bob F

    Bob F Guest

    Or, one could store the equipment in a cabinet with a small heater or light bulb
    on all the time.
     
  8. N_Cook

    N_Cook Guest


    The problem is in Nimbin , NSW, Australia, with loads of river water around
     
  9. Phil Allison

    Phil Allison Guest

    "Nutcase Kook"
    "Phil Allison"

    ** ROTFL - Nimbin ???

    The place is chock full of dope smokin' hippies !!!

    And it is semi tropical too.

    http://en.wikipedia.org/wiki/Nimbin,_New_South_Wales

    Trust NK to have a contact there.



    .... Phil
     
  10. Guest

    I worked inside Cheyenne Mountain, Colorado in the mid-1960's on the
    military installation there. It was in the early stages of
    construction, the building inside the hollowed-out mountain was
    constructed, but the mountain itself was still dripping moisture onto
    the building and the air exchange system was not operational yet.

    Humidity was 98% or so, at about 60F. There was mold growing on all
    the electronics in the telco products that I was trying to debug. The
    gold-plated pwb circuit pack connectors even had mold growing on the
    contact fingers. Needless to say, the connections were not reliable.
    Fortunately for the USA Defense System, they did get the humidity down
    and the communications equipment went on to become reliable.
     
  11. N_Cook

    N_Cook Guest

    I worked inside Cheyenne Mountain, Colorado in the mid-1960's on the
    military installation there. It was in the early stages of
    construction, the building inside the hollowed-out mountain was
    constructed, but the mountain itself was still dripping moisture onto
    the building and the air exchange system was not operational yet.

    Humidity was 98% or so, at about 60F. There was mold growing on all
    the electronics in the telco products that I was trying to debug. The
    gold-plated pwb circuit pack connectors even had mold growing on the
    contact fingers. Needless to say, the connections were not reliable.
    Fortunately for the USA Defense System, they did get the humidity down
    and the communications equipment went on to become reliable.

    +++++

    If you include interpretting flocks of geese as incoming Russian missiles ,
    and going to DEFCON whatever , as reliable.
     
  12. Guest

    I only said the communications equipment (AT+T four-wire switches)
    became reliable. All the other "stuff" was not in my baliwick.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-