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Mystery part - what is this?

Discussion in 'Ham Radio Discussions' started by W7UUU, Feb 4, 2013.

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  1. W7UUU

    W7UUU Platinum Subscriber Life Member Platinum Subscriber QRZ Page

    I've been dinking with electronics since I was 8 (I'm 51 now). I've taken apart
    a bunch of gizmos over the years for parts to use in other projects.

    But this one has me stumped.

    I bought a chassis on eBay (sweep generator) for the parts within. It had a lot
    of cool retro bits to use in some homebrew projects - which is good, because
    its days as a sweep generator were long past - lots of deterioration except for
    the parts I was after (National verniers, power transformer, choke, etc.).

    This gizmo was on a fairly sophisticated homebrew chassis - see photos. One
    tube on top... VHF coil on the top as well. What you see in the first photos is
    just a small subassembly of the larger unit. I removed the subassembly for
    the photo.

    I have NO IDEA what this is.... and it's driving me nuts! :D:D

    Weighs about 2 pounds, is mildly magnetic (see how it loves tube shields!),
    and most interestingly (to me) is that the only terminals on it, on the top,
    have ZERO DC CONTINUITY! That rules out a coil of any type that I can
    think of ... or transformer ... Diameter is 2.5", about 2" tall.

    It also appears very sealed - think "Military" - thick brown glue on every screw
    and every possible entry point.

    What the hell is this thing? And why would it be in a sweep generator homebrew
    project from the 1950s?

    Dave
    W7UUU
     

    Attached Files:

  2. KL7AJ

    KL7AJ Premium Subscriber QRZ Page

    Anyone can tell you it's a "doohickey". But more precisely, it's a rotary switch doohickey.
     
  3. K8ERV

    K8ERV Ham Member QRZ Page

    Motor driven capacitor to sweep a hf osc?

    Whatever it is, that's it.

    TOM K8ERV Montrose Colo
     
  4. KL7AJ

    KL7AJ Premium Subscriber QRZ Page

    No...actually, it's a SATURABLE reactor swept oscillator. This is how you did it before the Varactor diode was around. You force more or less DC current through one winding of a core, which changed the inductance of the other winding. A fixed magnetic field "biased" the reactance into its linear range. It took quite a BIT of DC current to do this...which is why the resistance you measured is so low.

    ERic
     
  5. KB1NXE

    KB1NXE Platinum Subscriber Platinum Subscriber QRZ Page

    Early Flux Capacitor. I think version 1.2 or there abouts. Only .000001200 jigawatts...
     
  6. KL7AJ

    KL7AJ Premium Subscriber QRZ Page

    Or a Clux Fapacitor
     
  7. W7UUU

    W7UUU Platinum Subscriber Life Member Platinum Subscriber QRZ Page

    But it has ZERO DC continuity, and only 2 terminals.... ???

    Dave
    W7UUU
     
  8. N2EY

    N2EY Subscriber QRZ Page

    It's a wobbulator.

    73 de Jim, N2EY
     
  9. KL7AJ

    KL7AJ Premium Subscriber QRZ Page

    Should have at least a couple more terminals on the top, where the oscillator connects. You should be able to take the "can" apart and see the toroid inside.

    ERic
     
  10. W7UUU

    W7UUU Platinum Subscriber Life Member Platinum Subscriber QRZ Page

    Yes - I now realize the phenolic board has ONE terminal on it as well....

    I'm going to open it up right now to see what's inside :D:D:D

    Hopefully it's not the "well of souls" and when I open it, my face will melt and what not....

    Dave
    W7UUU
     
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