Connect with us

Temperature probe for Tek 7D13?

Discussion in 'Electronic Equipment' started by Robert Baer, Aug 26, 2004.

Scroll to continue with content
  1. Robert Baer

    Robert Baer Guest

    Does anyone know the designation/PN for the Tektronix 7D13 Digital
    Multimeter plugin?
    Also, the schematic and/or how to make working equivalent?
     
  2. mike

    mike Guest

    Most of the temp probes of that vintage were merely a transistor
    at the end of a wire. Tiny ceramic Pill packages stuck on the end of a
    stick.
    If the 7D13 uses the difference voltage at two current levels, most
    any transistor will work.
    mike

    --
    Return address is VALID.
    Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
    Bunch of stuff For Sale and Wanted at the link below.
    Compaq Aero floppy,ram,battery.
    MINT HP-41CV, 2-METER AMPS, 200CH SCANNER
    http://www.geocities.com/SiliconValley/Monitor/4710/
     
  3. Robert Baer

    Robert Baer Guest

    Thanks for the info; i really appreciate it.
    The Tek 7D13 uses a special 4-pin connector; two are closer to the
    entry than the other two, insulation making a "D" shape.
    It would be hell to find a matching connector.
    Then there is the case of what the "extra" two are for...
    ....and how wired.
     
  4. Jim Yanik

    Jim Yanik Guest

    A "Lemo" connector. Digi-Key sells them,IIRC.
    One's used as a shield connection,IIRC.
    IIRC,the same temp probe was used for the DM501(non-A).
     
  5. Robert Baer

    Robert Baer Guest

    Someone was kind enough to e-mail me a link to a DM501 schematic.
    With that, i found two corroded tantalums (corroded weld at case on
    negative lead); replaced them with aluminum electrolytics, and it works
    fine.
    2 wires are for emitter and collector; shield (ground) is the base of
    the NPN.
    The other 2 in this case are for measuring voltage.

    I appreciate the help from everyone.
    Thanks!!
     
  6. mike

    mike Guest

    The connector is called a LIMO connector. Not sure whether that's the
    name of the manufacturer or what.

    You really should get the correct info for the 7D15. TEK used two
    methods. One just based the reading on the voltage of the remote
    junction. A more accurate method measures the voltage at two different
    currents and does some math to get the temperature. I think it matters
    how the transistor is wired...but maybe not. I think the transistor is
    much more critical for the one-current method. If it's got a junction,
    the two-current method will work.
    Can't hurt to try it.
    mike

    --
    Return address is VALID.
    Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
    Bunch of stuff For Sale and Wanted at the link below.
    Compaq Aero floppy,ram,battery.
    MINT HP-41CV, 2-METER AMPS, 200CH SCANNER
    http://www.geocities.com/SiliconValley/Monitor/4710/
     
  7. Robert Baer

    Robert Baer Guest

    Thanks; Limo is the name of the manufacturer of many spiffy and
    compact connectors that make the old MIL styles look like elephants by
    comparison.
    Got on their website and found the mating connector.
    I was not aware that Tektronics used two methods - had the impression
    they used the two current method, as that needs almost zero calibration
    and allows probe interchangeability.
    The "math" is in the form of simple differences, and ordinary op amps,
    resistors, etc are used.
    The schematic of the DM501 was very useful, and (except for part
    numbering like Q123) essentially identical to the 7D13.
    I found the other pair of wires is for remote voltage measurements.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-