Help identifying an old circuit component

Discussion in 'General Electronics Chat' started by JeffM, Mar 9, 2015.

  1. JeffM

    Thread Starter New Member

    Mar 9, 2015
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    I could really use some help identifying this circuit component. Most of the other components are new original stock from the 70s and 80s and all my attempts to identify this guy have been in vain. Any help would be appreciated, including what that symbol is/means.

    Thanks!
    Jeff

    IMG_6849b.jpg
     
  2. #12

    Expert

    Nov 30, 2010
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    Those are capacitors. Apparently 10pf at a rather high voltage.
     
  3. bwilliams60

    Active Member

    Nov 18, 2012
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    Polyester film capacitors. 10pF??? Measure them with a capacitance tester. Anything written on the back?
     
  4. #12

    Expert

    Nov 30, 2010
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    I think mica capacitors. Remember, these are 40 to 50 years old. Only a couple of decades after paper caps were used (in radios) instead of poly-film.
     
  5. JeffM

    Thread Starter New Member

    Mar 9, 2015
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    Nothing on the back. My fluke multimeter cap test showed OL. First time I've ever used the cap mode, so I may need to set it down from autoscale? I tested a similar blue cap from the same era and it dialed in the right capacitor value (confirmed by google search of the lettering), but this one wouldn't register.
     
  6. #12

    Expert

    Nov 30, 2010
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    10 pf is so bloody small that the leads on your meter could cause 10% error. No surprise if the meter wasn't designed for 10 pf. Do you have meter leads or just some, "jam it in here" clips?
     
    planeguy67 likes this.
  7. #12

    Expert

    Nov 30, 2010
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    I just looked up 2 Fluke meters and their smallest measurement is 10 pf (0.01 nf)

    Try attaching a few in parallel and see if that gets a reading.
     
    planeguy67 and Lestraveled like this.
  8. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Actually they appear to be 100pF etched/silver-mica caps -- in my experience numerical codes (in contrast to color codes) never set the multiplier digit = 0 hence such figures represent non-coded values. thus, in this case, "100" has the same meaning as "101"...

    Just my $0.02

    Best regards
    HP
     
    Last edited: Mar 10, 2015
  9. #12

    Expert

    Nov 30, 2010
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    If it was 100 pf, it would cause a proper reading on a meter that has a lower limit of 10 pf...assuming the meter isn't broken, and Fluke has a good reputation.
     
  10. JeffM

    Thread Starter New Member

    Mar 9, 2015
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    I have the Fluke 111 meter. I'll try measuring in series.
     
  11. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Interesting that the instrument shows an 'over-range' indication though (leaky NOS SMs are almost unheard of)... Absent a proper LCR indicator he needs to take your advice (i.e. measurement of several paralleled devices)... :)

    Best regards
    HP
     
  12. Hypatia's Protege

    Distinguished Member

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    You want the measured caps in parallel! :D
     
  13. JeffM

    Thread Starter New Member

    Mar 9, 2015
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    Yeah I meant parallel... still no luck. 2015-03-09 22.07.16b.jpg
     
  14. Hypatia's Protege

    Distinguished Member

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    Please have a look at the caps on the resistance scale... Leaky/shorted caps often give upscale capacitance indications

    Best regards
    HP
     
  15. #12

    Expert

    Nov 30, 2010
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    That looks like a new meter.
    and...HP beat me to the answer.
     
  16. JeffM

    Thread Starter New Member

    Mar 9, 2015
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    I get 0.3 ohm for all 10 in parallel. I get 10.3 ohm for one single one. confirmed across a few different tests.
     
  17. #12

    Expert

    Nov 30, 2010
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    Bingo. They are 10 ohm resistors.
     
  18. Hypatia's Protege

    Distinguished Member

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    Curious... They're not merely "resistors in cap's clothing" or the combined value should ~ 1.03

    Best regards
    HP
     
  19. JeffM

    Thread Starter New Member

    Mar 9, 2015
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    I cut one open earlier and it has a white center. Any idea what that volt symbol means? I couldn't find either a resistor shaped like this or that voltage symbol in my searches.
     
  20. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Yes! Of course -- I stand corrected! :D --- Maybe swering off java wasn't such a good idea after all (no offense Oracle ;))

    Best regards
    HP
     
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