My SB-220 plate meter stopped working, although I have normal power output.

Discussion in 'Amateur Radio Amplifiers' started by W7PV, May 20, 2020.

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  1. W7PV

    W7PV XML Subscriber QRZ Page

    Several years ago I installed the rectifier/metering board mod from Harbach, and it has worked fine. Recently however, my plate current meter stopped working even though my power output meter shows normal output. Is there an easy way to test just the meter before I pull and test the shunt resistors?
     
  2. W1NB

    W1NB XML Subscriber QRZ Page

    I think I read that those meters are 200 uA movementS, so a 15k ohm resistor in series with a AAA battery should cause the meter to swing to about mid point. Just observe polarity.
     
  3. W7PV

    W7PV XML Subscriber QRZ Page

    Thanks for your reply...... meter checked out fine as did other components. Amp now working fine...... not sure what the problem was; perhaps a loose/bad connection somewhere.
     
  4. W1QJ

    W1QJ Ham Member QRZ Page

    Heath used solid wire to connect down to the meter function switch sometimes the wire breaks .
     

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