Got shocked BAD

[Structo]

Yeah I remember something similar.
It really doesn't take all that much to stop your heart.

Be extra vigilant guys!

[Cliff Schecht]

Or don't build with those stupid old vacuum tubes. Transistors are much safer to work with.

[renshen1957]

Hi Everyone,

Anyone out there besides me that puts on Rubber Gloves (besides the one hand in the pocket, etc) when working on amps?


Best Regards

Steve

[Matt D]

Erik, Do you have a link to the post you were talking about.

I have a Marshall 18 watt Tremolo build that has done the same thing intermittently. When inserting or removing a cable I have gotten a shock just very briefly through my fingers touching the chassis of the amp. It has stopped doing this for now but I really would like to understand why it was happening and fix the problem.

[Prairie Dawg]

A cautionary tale for you all.

I just got zapped by an Ampeg Gemini 1 yesterday. The cap can is insulated from ground by a bakelite wafer and there's a ground wire that goes from the outside of the can (a lug) to a point on the circuit board. That ground wire to the circuit board had cracked at the termination point, with the end result that the can was now hot if you had a hand on the chassis and touched the outside of the can.

Rang my fricken bell.....

[overtone]

Hi Everyone,

Anyone out there besides me that puts on Rubber Gloves (besides the one hand in the pocket, etc) when working on amps?


Best Regards

Steve

Steve, I admit that I was in rubber on my first two amps and scared as hell. Her indoors was even more worried.
These days there are actually very few occasions when I am inside an amp while it is live at high voltage. That will be usually to check the voltages or taking a look with the scope. I use low voltage AC to check the amp in stages during a build, or during a divide-and-conquer repair. That will show up most problems without risk to you or the parts.
For new builders: when I started out I never understood how you were supposed to take meter readings with one hand in your pocket, really I didn't. Then an old radio ham gave me some of the probe clips shown below. These are one of my most used tools of all.
Stay safe everyone, best, tony

[overtone]

double post...

[davent]

Just one niggle Mark, I believe electrocuted means killed by electricity.
He received a life threatening electrical shock.

Sorry for being anal retentive about it.

This recently came up on another forum and it turns out that in the Oxford Dictionary (GB) that they define electrocute to mean injure or kill by electric shock. I'd always thought it strictly meant to kill, a cultural thing i guess.

http://oxforddictionaries.com/definition/electrocute

dave

[Nephilyn]

Hi Everyone,

Anyone out there besides me that puts on Rubber Gloves (besides the one hand in the pocket, etc) when working on amps?


Best Regards

Steve

I just finished my first build and always(most of the time) use rubber gloves and eye protection when testing, but as I approached the end of my build I have become
more confident with High Voltage DC. By the way I work with 400VAC
almost every day at work as I am a power systems technician, its just that I've read so many warnings about working on HVDC in amps that I have developed a slight paranoia about it.

Note that rubber gloves is not the right stuff to use when working on HV and one should use gloves designed and rated for the application.

Lee

[Prairie Dawg]

I've never used rubber gloves while working on amps and I'd think that when your hands get good and sweaty in them and there's but a mere pinhole you're going to get hit just the same. Dry hands are a better deal. Just my opinion, your mileage may vary.

[Cliff Schecht]

Nephilyn above had it right. Rubber gloves of any sort (white ones, nitrile gloves, etc..) are not in any way intended for insulating from HV and most likely will break down even if they are completely dry. Unless the gloves you are using are rated for HV protection, they should be considered useless for the task (why take that kind of a chance?).

[Leviman]

I just wanted to say, I'm damn lucky. I've been shocked by the B+ a few times. Once on my Pignose G40V. I installed metal case 6L6's but pignose didn't think of those tubes when they built the amp. So they used the pin that's used to ground the cases as a junction point for their anode resistors!! Needless to say, I got shocked when I saw one of the tubes a bit crooked and went to straighten it (with the amp running). Scared the hell out of me too. I was fooling with a computer monitor once too, and got shocked by that. After that I ripped the thing apart and took the bits I wanted (found some 4558s on the board, planned to make a boost pedal).

[TUBEDUDE]

i've taken a few nasty shocks over the years. One of 440vdc off of a transmitter final with the addition of high frequency R.F. The burn mark on my hand took 14 years to dissappear. The first shock was as as a toddler, sticking a knife into a wall outlet. Then as a 10 year old, i was trying to remove a stuck piece of toast from the toaster. But tthe worst, and the one most likely to have killed me was as a 16 year old. i was working on my grandfathers tube receiver. I had removed the steel chassis from the wooden box and had the chassis balance on my thighs, shorts on, and was counting the tube socket pins to find the plate of the 7591 tube when the finger i was using to count the oins made contact with said pin. I have been much more careful since. I suppose a case could be made for having some neurologic damage previous to that misadventure, but I'm pleased to find out if i suffer much more neurologic damage i can become as I.T. professional. J.K. The one handed technique has served me well in the last fourty years and I highly recommend it.

[Deric]

The first shock was as as a toddler, sticking a knife into a wall outlet.

Well, at least now we know where Tom (Structo) got his avatar!

[Andy Le Blanc]

I got wooden bench and floors and rated shoes, the last time I got it bad was
from a leaky PT when I brushed against a grounded AC receptacle strip while
positioning the amp chassis on the bench...