Manna from Heaven: Donated Heathkit SB-650 Digital Display for K1T

Discussion in '"Boat Anchor" & Classic Equipment' started by W7UUU, Jun 4, 2016.

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  1. W7UUU

    W7UUU QRZ Lifetime Member #133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Oh, trust me... :)

    Such as: HR-10b, Ameco AC-1 (!!), SB-620 recap, SB-610 recap, SB-640 restoration, put all SB rigs back in painted boxes, build up mock HD-10 (I have one from a ham fest just for the purpose) with a K1EL contest keyer inside for use in K1T, rearrange main operating position and start populating Heath rigs for K1T, full bench reset to optimize work flow and space... I could easily think of others

    Exactly. I essentially have the full kit of parts, sans PCB, to repair another SB-650 so long as it has a good PCB

    Just for good science, I'll test it once I get out to the shop. Easy to test now actually in situ using the actual pins: I'll just inject the 170v DC from the built up supply with an ammeter inline and see if it conducts at all between two adjacent pins.

    I'll probably keep the SB-650 transformer and build up the power supply portion of the PCB ( just for testing future Nixie tubes) - intentionally cutting it down and reusing the original PC Board section just so it's not a total loss... perhaps house it in one my spare HD-15 phone patch boxes, with my usual nice Heathkit panel art - what would be the model? Hmmm... PS-650 Nixie Power Supply? (back-burner project however - for one night next winter when I'm bored)



    Thanks Jim! I also hate to see this project die like this - very anticlimactic, and sad at the same time. But I just don't see a viable and practical solution, especially when I have a fully working SB-650 sitting right on the bench. I don't care to be defeated, but there comes a time...

    Another cup o'Joe then off to the shop for a dielectric breakdown test, with a dialectic on the dielectric to follow in summation :)

    Dave
    W7UUU
     
    Last edited: Sep 3, 2016
    N2EY likes this.
  2. W7UUU

    W7UUU QRZ Lifetime Member #133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    And the answer is: Yes, dried Elmer's glue in fact is an insulator. Image below, 2mA range, full 169.9 VDC into adjacent pins in the same dried "glue pool" and at least as far as my meter is concerned, at that voltage anyway, the glue is just fine as an insulator. Now, I don't think I'd want to put my Megger on it or trust my life to Elmer's glue in a high-voltage circuit - but for the academic point that this now is, we can at least conclude that the SB-650 project has confirmed: Yes, feel free to use Elmer's or any other PVA-based "white glue" to separate machined pins used for a Nixie tube project :) (Of course, I only tested for a few minutes - it's possible there could be long-term breakdown issues I suppose - but it's no longer relevant)

    Dave
    W7UUU

    1-2016-09-03 10.50.29.jpg
     
  3. W7UUU

    W7UUU QRZ Lifetime Member #133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    sigh...

    my_tombstone.jpg
     
  4. N2EY

    N2EY Premium Subscriber QRZ Page

    Thanks!

    Not to say "I told you so", but......I do recall a prediction......

    RIP SB-650......for now.

    73 de Jim, N2EY
     
    W7UUU likes this.

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