help identify capacitor value

Discussion in 'General Electronics Chat' started by lokeycmos, Jan 22, 2014.

  1. lokeycmos

    Thread Starter Active Member

    Apr 3, 2009
    hello, im working on a speaker crossover for someone. I need to replace a capacitor on it, but not sure of the value I need. on the cap itself it is labled as"1.8K" and "250v". but if you look at the board itself it says "4.7uf 100v" could someone please clarify this for me so I know what value to order? thanks!
  2. ian field

    Distinguished Member

    Oct 27, 2012
    The lower capacitance will need a higher frequency to do what its supposed to do.

    Look round the other side for any markings that look like 475 - if not, either replace with the same value you see in front of you, or replace the capacitor in *BOTH* crossovers with the same value - ie; what it says on the board.
  3. lokeycmos

    Thread Starter Active Member

    Apr 3, 2009
    what value is 1.8 on the cap? im not real familiar with cap codes. I think the K is the tolerance.
  4. paulktreg

    Distinguished Member

    Jun 2, 2008
    If I was to hazard a guess then I'd say it was a 1.8uF +/-10% 250V polyester capacitor?

    ... although it should be written 185K or 1u8K?
    Last edited: Jan 22, 2014
  5. #12


    Nov 30, 2010
    1.8 is a valid number, but I feel so stupid saying the obvious. It's either 1 uf or 1.8 uf.
    Please don't throw things at me.
  6. MrChips


    Oct 2, 2009
    For a 3-way crossover, 4.7μF and 0.2mH seems about right for the tweeter.
  7. tubeguy

    Well-Known Member

    Nov 3, 2012
    Based on the pcb markings it looks like a 3-way x-over.
    It's more likely the 4.7uf marked the pcb is correct if it is being used for the hi-pass to the HF driver (tweeter). a 1.8uf is still ~ 20 ohms at 5000hz which seems a bit high (impedance-wise).

    But to be sure, it would help to post a schematic. If you don't have one it might not be hard to follow the traces and draw one.

    What type tweeter or hf horn is being used?

    Edit: Mr Chips - was typing etc... :)