572 tubes update

Discussion in 'Amateur Radio Amplifiers' started by W8JX, May 15, 2015.

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  1. REASTON

    REASTON QRZ Member

    No they did not install them assembled. They assembled them from assemblies. Triton who bought Eimacs glass tube line didn't want the pumps. It was faster to just cut them up. You need to stop making stuff up about things you know nothing about.
     
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I've never done this, either and don't quite understand why it would work.

    The leak in a power grid tube like this could be at any of the base pins or the anode pin out the top, assuming the glass is all intact. It wouldn't happen from solder melting or reflowing, as the seal is kovar to glass and any solder is way outside of that.
     
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    I may need to make a Youtube of my setup, and how it works, If I can find a bad tube to test.

    I need a new Bigger Pickle Jar, For the bigger Tubes.

    My Ball Jar is a bit small.
     
  4. AA9G

    AA9G Ham Member QRZ Page

    Oh that would be super awesome.
     
  5. KA9JLM

    KA9JLM Ham Member QRZ Page

    The best test for a Good Vacuum pump is if it can boil off water at room temperature.

    If it can not do that, Then it won't be much good for Vacuum Tube recovery.

    If you have a good Vacuum gauge, You can tell when the tube is Fully Evacuated.

    What would be way cool is to add some Getter material, I have not tried that yet.


    Anyone have any 572s that need rebuilt ?
     
  6. VE7GPG

    VE7GPG XML Subscriber QRZ Page

    Yes - I have two !

    Greg
    VE7GPG
     
  7. ND6M

    ND6M Ham Member QRZ Page

    correct

    Does it matter? You can only pull what you can pull and it's either good enough or not.[/QUOTE]

    not quite correct,.... you can "pull" more vacuum than your pump is rated at, if you know what you are doing.

    the vacuum you can pull using a rotary vane pump is marginal (29 - 30 INCHES of Hg) at best, thats fine for A/C or refrigeration stuff, but not for quality tubes.

    When I hand made tubes, a vacuum pump was used for the "rough" vacuum, then the tube was attached to a ION DIFFUSION pump, and the tube was baked at 950 degrees for 48 hours with the pump pulling.

    the tube was then sealed and allowed to cool to room temp.

    I routinely pulled vacuums of 10 to the minus 15 TORR.
     

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