Need help with these potentiometers

Discussion in 'The Projects Forum' started by SvenS, May 7, 2010.

  1. SvenS

    Thread Starter Member

    Nov 18, 2008
    Have two pots that are in need of replacing in my older 1980's White's 5000/d Series 2 metal detector, can't find the schematics anywhere on the web.

    Tried spraying them with contact cleaner, did un-freeze them so they worked, but not well enough. They definitely need replacing. Only problem is not 100% sure as to the pot values. Did use my multimeter (Radio Shack) not sure it's 100% accurate.

    The pots are CENTRALAR brand

    Hany help determining the pots values would be appreciated, can't find that brand name doing a google.
  2. BMorse

    Senior Member

    Sep 26, 2009
    The numbering may indicate the value "502" might be 5K ohms, and the "503" might be a 50K ohms.....

    What readings do you get with the multimeter?? if one lead is connected to the center pin and the other to one of the outer pins, record the readings you get when you move the wiper from one extreme to the other. The RatShack meter may be inaccurate but it could give a good base for figuring out the values.

    B. Morse
    Last edited: May 7, 2010
  3. SvenS

    Thread Starter Member

    Nov 18, 2008
    You could be right

    I came up with 5K and 50K as my guess with that multimeter
  4. SgtWookie


    Jul 17, 2007
    Measuring across the two end terminals will give the total resistance of the pot.
    Measuring between one end terminal and the middle terminal (wiper) will give you an idea of whether the pot is linear or log (audio) taper.

    It's important to not only get the same type of pot (linear or log/audio), and particularly in the case of the log/audio taper, connect the new pot in the same way the old pot was connected.