[Dark High]

I'm starting to work on my Philco 40-180 I got recently, but before I started messing around with the insides, what are the risks? If it's unplugged, am I in the clear? Will anything discharge when I touch it? I know some old tube TVs can still hold a charge even if it's unplugged. Just checking.

Thanks,

Dark

[codefox1]

If the old electolytics can still hold a charge it'll zap you. Discharf=ge them through a good 10 K resistor for a minute just to be sure. Arm to arm discharge can be a real problem, especially as we age. Please do not ask me how I know.

[37silverstreak]

I agree. If the set is unplugged, the electrolytics can still hold enough of a charge to shock you. when the set is plugged in, I always use the "one hand in pocket" rule I was taught in electronics servicing at tech college, which means to work on an energized circuit with one hand only, that way if you touch the circuit the shock will only travel through your hand, which will hurt but won't do serious damage. the real danger is if you make a path for electricity that will allow it to pass through your body, which can kill!

[Dark High]

Ok good. Shocks I can handle, the shocked to death is what I'd like to avoid.

Thanks

[dcastor]

Starting to get off-topic, but...

An electronics professor I had in college talked about working on a Navy submarine. He said when it was really time critical to find blown circuits he would stand on a rubber mat and touch each circuit with the back of a finger. He said he wouldn't get much of a jolt as he was insulated, but he could "feel" the current flowing by his hand. If his arm or hand contracted from the electricity it would tend to pull his hand off the circuit instead of grabbing it harder.

I think he was nuts!!

[Arran]

It may or may not hold a charge, many AC sets have a discharge resistor between the + and - of the filter cap of severaly 100,000 ohms.
Regards
Arran

[ipwizard]

I've been shocked a couple times both from stupidity.

First time was from touching a lead on an IF transformer on an Packard Bell AC/DC set. 250VDC into my finger which also touched the chassis at the same time hurts like a BI**H.

Second was from touching the electrolic caps in the power supply of my A.C. Dayton when I didnt have the radio chassis connected (was testing the newly rebuilt power supply). Cap was a 10uf 450V.

To me the high DC voltage was the worst, but getting shocked is never a good thing and can always be avoided. I now use the one hand in pocket when poking around in a live radio.

[codefox1]

Spend the few pennies on bleeder resistors when overhauling a set to make the chassis a little safer after shut off an disconnect. Plenty of information here and elsewhere.

[cwysong]

And get yourself a wooden stick about 18 inches long. Make one end look like a pencil. Use this as a probe. It will show you problems while power is on the chassis.

Chris