Remembrances of vacuum tube days
As a young teenager, I developed a love for electronics which became a lifelong love affair. In those days vacuum tubes were the norm and solid state devices such as transistors weren't in usage then....
Forum Discussion
Gdetrailer wrote:JKJavelin wrote:
I sure don't miss the electrical shock you can get from those tubes if you didn't ground them (yes, with the TV unplugged). I got it several times.
JK
Actually shocks were not just a "tube" problem it was very common in a lot of solid state equipment, that was caused by manufacturers being cheap skates and not using a transformer in the power supply and tying one side to the 120V line DIRECTLY to the chassis.. :E
It is called a "HOT" chassis and if not careful when servicing would end up biting you or worse yet becoming a pretty good arc welder when attaching serving equipment like oscilloscope ground to the chassis..
With most older equipment having non polarized line cords you can imagine the havoc that can cause when the HOT side of the line ended up on the chassis.
Spent a lot of my younger yrs servicing 1970s-1990s consumer stuff with one hand stuck in my pocket for safety.
And for the record, CRT TVs, the 2nd anode connection to the tube is to be respected.. CRTs can hold a second anode 20KV+ charge for YRS with out power, was taught to take a long flat blade screw driver and a clip lead from it to chassis ground before ever touching that connection..
yup, the bakelite or phenolic knobs on the front are all that protected you from a potential shock on those old sets. First thing I did and do if I come across one of those old units that I want to keep is to switch to a polarized plug, with the neutral side tied to the chassis, especially those with no transformer.
