Yet another KL7AJ exclusive "Handy Hint"

Discussion in 'General Electronics Chat' started by KL7AJ, Nov 25, 2008.

  1. KL7AJ

    Thread Starter Senior Member

    Nov 4, 2008
    You got it here first!

  2. markm


    Nov 11, 2008
    Heh, heh, heh. Most of a lifetime ago, I was training new Air Force technicians to repair radar sets. The newest guy was working on a set with an apparently dead local oscillator klystron tube and apparently thought the connector might be loose (a good thought, but his next action wasn't so well thought out). He squeezed the connectors together with fingers on one side and thumb on the other, with power on, and got an 800V poke. The tube HV power wire turned out to be broken but still held inside the silicon rubber at the back of the connector, so when his finger pushed the rubber back... It's a good thing that this was a small klystron and the power supply was rated in microamps, but it had some capacitance and he yelped.

    So I told him he was doing well at troubleshooting, but needed to think a bit more about safety before he made a move. The trouble is, the next set had the wire broken in the same place, and he found it the exact same way. Ouch!
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    There was the night a series of us went out to a computer because nobody could get a voltage reading from it that was the same twice in a row or that was anything like the rated voltage.

    We pulled all the chassis from the cabinet (these things stood 7 feet high and weighed 2200 pounds) to get at the transformer. The ground lug was there, along with the nut resting on top of it. But the copper stud had vanished. Perhaps two ounces of copper had left behind no more than some green stains on the procelain cup surrounding it.

    We never did figure out what had happened. We did put in a replacement transformer, but the computer ran fine before and after.