Well, it finally happened, I got shocked....

Discussion in 'Ham Radio Discussions' started by K8CCA, Mar 1, 2021.

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  1. K8CCA

    K8CCA Ham Member QRZ Page

    It was from Vacuum tube equipment, but it was not as I had expected it to be however, but yeah it hurts really bad when it gets ya. Here's what happened.....

    I have rebuilding and playing with old radio gear for many years. Have rebuilt lot's of stuff radio stuff such as Drake L4B, Johnson Viking's, Johnson Valliant's, tons of receivers, and even an old Zenith round screen TV. Never got zapped. A few years ago I started messing around rebuilding guitar amps. Really pretty simple compared to radio receivers. So I had picked up a old 6V6 tube amp and rebuilt it and found when testing that the speaker was trashed, so I used alligator clips to connect to another speaker in a different cabinet. I was playing my Les Paul and one of the clips fell off the speaker. I had my right hand muting the strings and with the other had reached into the cabinet to reconnect the speaker and BAM! I got bit hard. Not really sure what I touched, perhaps the chassis was hot. Worse case scenario, from my left hand in amp across my chest to ground thru right hand on the guitar strings. Hurt pretty bad, not even sure what happened, but I got hit pretty hard. I just never even thought about it happening as I was playing guitar and not thinking about shock hazard. Luckily I was ok, not sure what the voltage was but it didn't kill me. So the moral to this story is to pay attention when you are playing with this stuff and sticking the old fingers where they don't belong.
     
    WD4IGX, PU2OZT, K3EY and 4 others like this.
  2. W7UUU

    W7UUU Principal Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Wow! Glad you're OK. I've done the same in years past and know exactly how it feels.

    I was taught to always keep one hand in a back pocket when working in the HV section of a chassis. The one time I broke that rule, I got zapped much like you did (your guitar surely provided a nice return path).

    Again, glad you're OK and can post about it :)

    Dave
    W7UUU
     
    WD4IGX, WD4ELG, WA9SVD and 2 others like this.
  3. N1FM

    N1FM Premium Subscriber QRZ Page

    Words to live by. Worst scenario is across the chest which can stop the ticker. I've been zapped a few times over the past 40+ years (tube transceivers and amps) but the worst pain comes from RF burns. It also tends to kill tissue so that the burned flesh falls out like a cork on a wine bottle. Not pretty and hurts like hades.
     
  4. KQ8W

    KQ8W XML Subscriber QRZ Page

    Old guitar amps are notorious for shocking people when the plug was not polarized. Glad you're still here to tell the tale!
     
    PU2OZT, N1VAU, K0UO and 2 others like this.
  5. K4PIH

    K4PIH Ham Member QRZ Page

    There have been several guitar players over the years that have died from a jolt while playing. I don't remember by name but one was sitting on a metal stool when it happened. Glad to hear you are ok.
     
    PU2OZT likes this.
  6. W7HV

    W7HV Ham Member QRZ Page

    When I was a kid back in the late '50s we had an AC/DC AM radio on top of the fridge that would give you and healthy shock. I've been shocked many of hundreds of times since, most minor but some pretty good ones. I think it's good for you...up to a point. HI HI
     
  7. N8YQM

    N8YQM Ham Member QRZ Page

    Ouch! I've also heard that certain guitar amps can shock you through the strings. Glad you're still with us!

    Most painful shock I got was repairing some stage lighting for a community theater. Our group had a bunch of old stage lights donated, but most of them had the wrong kind of plugs to go with our lighting system. We bought a bunch of new plugs, and went through them putting new plugs on, replacing bulbs, fixing broken wires, etc.. I had just finished putting one lamp back together that already had the correct plug on it, but it didn't have a ground wire. Not a big deal, or so I thought. Little did I know that the ceramic lamp base inside was somehow missing the insulator that went between in and the body of the lamp, and the center pin of the socket was touching the metal body of the lamp. So, having just stuck a new bulb in it, I'm holding the lamp in one hand, and plugging the plug - which had a grounded metal shell around it - into the outlet. Oh, and my hand was a little sweaty because I had just finished screwing the lamp cover back on with a screwdriver.

    OWWWWW......

    Dropped the lamp on the floor, and proceeded to shake my tingling arm back into feeling. We replaced the insulator and added a ground wire to that lamp. Our director decided to have a little fun since we were getting ready to put on a production, so in the program under the list of production staff he added "Sparky" as my middle name. Ha ha, very funny.
     
    NK8I likes this.
  8. N3HGB

    N3HGB Ham Member QRZ Page

    When I was a kid I went to play with a Meisner Signal Shifter in bare feet on concrete. This was really dumb and somehow it had B+ on the key. It felt like getting kicked in the chest by a really strong and angry mule :eek:
    Didn't do THAT twice!
     
  9. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    My closest call ever happened in November, 1960, around 2 AM, the night following the Kennedy-Nixon election. I had stayed up late, working on a homebrew transmitter while election returns were playing on the radio in the background. The rig used a pair of 1625s in the final, and I was trying to get some kind of modulator to work with it. I got the idea of taking a hi-fi amplifier, connecting an outboard plate-to-voice coil transformer in reverse to the 16-ohm output terminals, and wiring the primary coil in series with the +HV lead to the final, for plate modulation. I connected a microphone to one of the RCA plug inputs to the amplifier, plugged in the amplifier, and proceeded to make a test transmission to find out if I had any modulation. The one thing I forgot, or neglected to do, was to ground the audio amplifier to the rest of the station equipment.

    I was holding the mic in one hand, and reached over to the transmitter to make a tuning adjustment while speaking into the mic. Somehow I got hold of the metal panel of the transmitter, and immediately received in the vicinity of 1000 volts from one hand to the other. The muscles in both arms froze, and I couldn't let go with either hand. The only thing that saved me was that I stood up out of the chair and fell over backwards, yanking the microphone cord out of the connector. I remember hitting the floor and smashing a glass 6L6-G that was lying on the floor, with the back of my head. When I got loose from the voltage, both arms went for a few seconds into an uncontrollable spasm. I had burns all over both hands, and my arm and chest muscles were sore the next day. If that microphone had had a longer cord, or if the amplifier had a different type of receptacle other than the flimsy RCA connector it used, someone would had found me hanging on the thing the next day.

    I figured out what had happened. Insulation in the outboard audio output transformer could not withstand 1000 volts, causing the 16-ohm voice coil winding to arc internally to the plate winding, while the insulation in the amplifier's power transformer held up just fine, putting the amplifier chassis at plate potential, since the amplifier had no safety ground.

    Probably what saved me besides that loose-fitting RCA connector on the mic cord, was my age. I was 19 at the time, and might not have survived at my age now. Before that incident, I was getting zapped with high voltage pretty regularly and not taking it too seriously, although never from arm to arm. That made me a firm believer in HV safety precautions; I have never experienced a serious electrical shock since then, and still feel comfortable working with plate voltages up to 4000 volts or more.
     
    WD4IGX, W0PV, N5PAR and 2 others like this.
  10. KA4DPO

    KA4DPO Platinum Subscriber Platinum Subscriber QRZ Page

    I'm pretty sure most of us have gotten bit by B+ a time or two over the years. You have to admit, it is a great example of the old saying, experience is something you get, right after you need it.:D
     
    N5PZJ and KD2ACO like this.

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