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Yet another What Is This thread

Discussion in 'General Electronics Discussion' started by tryppyr, Nov 5, 2013.

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  1. tryppyr

    tryppyr

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    Oct 22, 2013
    Sometimes I run across things that seem to come from the dark ages. This is one such. Came in a Semiconductor Grab Bag.

    Any clues?
     

    Attached Files:

  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,259
    2,707
    Jan 21, 2010
    It could be a resonator, but that's not a semiconductor...

    (I'm guessing now) :D
     
  3. davenn

    davenn Moderator

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    Sep 5, 2009
    or a ceramic filter, in-gnd-out

    ( it may not have belonged in a semi. grab bag)

    Dave
     
  4. tryppyr

    tryppyr

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    Oct 22, 2013
    I'm not sure I can provide many more clues. I took out the multimeter and checked all combinations of the three pins. The needle never moved (yes, it's an analog meter).

    Any thoughts on how I could test this to get a better read on what it is? Not that I ever plan to use it... just intellectual curiosity.
     
  5. davenn

    davenn Moderator

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    Sep 5, 2009
    If you had a spectrum analyser with a RF sweep generator, you could sweep it across a freq range and see the results on the spec an. it would confirm the filter idea and would tell you its centre freq

    Dave
     
  6. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
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    Nov 28, 2011
    I've never seen anything like it, but I guess it could be a dual capacitor in a single package.

    If the markings mean that the capacitors are 87 pF and 10 pF (not likely, but just for illustration) it could be something like:

    1 -------| |--------2--------| |------3
    . . . . 87 pF . . . . . 10 pF

    In that case, if you measure the capacitance between each pair of pins, you would measure the following capacitances:

    1 to 2: 87 pF
    2 to 3: 10 pF
    1 to 3: a bit less than 10 pF (capacitors in series are like resistors in parallel).

    This is only a wild guess!
     
  7. tryppyr

    tryppyr

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    Oct 22, 2013
    I put it on my capacitance meter. Drumroll please...

    1-2: 1.814 nF
    2-3: 1.834 nF
    1-3: 0.211 nF
     
  8. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
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    Nov 28, 2011
    Hmm. That doesn't make much sense. If it was two 1.8 nF capacitors with a common terminal, you would measure 0.9 nF between pins 1 and 3. But I guess this does imply that it contains capacitance.

    You could try asking on a vintage electronics forum - perhaps vintage radio. There's probably someone out there who knows what it is.
     
  9. tryppyr

    tryppyr

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    Oct 22, 2013
    I do love a mystery. I'll check with the antique radio folks.
     
  10. tryppyr

    tryppyr

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    Oct 22, 2013
    The early opinion from the radio forum is:

    Actually that is an R-C network, probably a vertical integrator, based upon the Zenith 87- prefix. Somewhere there was a chart showing the values of the internal parts for the various Zenith 87- integrators.
     
  11. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

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    Nov 28, 2011
    You measured resistance across all combinations of pins and they were all open circuit, right? In that case it could not be an R-C integrator... But this guy sounds like he knows what he's talking about...
     
  12. tryppyr

    tryppyr

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    Oct 22, 2013
    There is still some discussion about it going on. The latest to opine about it stated:

    But elsewhere on the forum I saw a post specifically calling out the specs of an 87-10, showing a resistor value across two legs and a capacitance value across a different pair.

    And yes, I confirmed with a different meter that no pairing of the leads shows measurable resistance.
     
  13. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
    1,267
    Nov 28, 2011
    I found your other thread at http://www.antiqueradios.com/forums/viewtopic.php?f=6&t=235796

    Several people there have said that these components are notoriously unreliable. That could easily explain the fact that you don't measure any continuity across any combination of the wires. A second person confirmed that it's probably a Zenith R-C device with an 87- prefix. I suspect they're right. You might as well throw it away.
     
  14. tryppyr

    tryppyr

    228
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    Oct 22, 2013
    Yes, I probably should. I certainly have no use for it. Maybe my wife can use it to make something arty-crafty.
     
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