spark and hissing from crt EHT CONNECTING POINT

Discussion in 'General Electronics Chat' started by electrocraft, Jun 12, 2011.

  1. electrocraft

    Thread Starter New Member

    May 27, 2011
    Need help
    spark and hissing from CRT EHT connection point ie in side the CRT

    Is it because of faulty CRT ????????????

    help electrocraft

    Last edited by a moderator: Jun 12, 2011
  2. bertus


    Apr 5, 2008
  3. debe

    Senior Member

    Sep 21, 2010
    Picture showing discharging the HV using an earthing probe. The most likely place for arcing is from the conector under the insulating cap to the grey coating on the out side of the tube. Usualy caused by dust & moisture. Remedy is to clean the insulating conector & surounding glass on the tube, donot scrub the grey coating of as this is the earth. If this doesnt cure the arcing apply a little neutral cure silicone to the edges of the insulator & refit & let cure. The other posibility is if its arcing inside the tube then the EHT may be excessive should be around 25KV, or the tube is no longer under a vacumm.