Doesn't it totally defeat the purpose of a polarized plug if it is installed the opposite way around? Before the change you had 50% chance of plugging it in the wrong way and now it is 100%. What am I missing?
Most of these old radios were wired with the switched side of the power cord connected to chassis (or common/ground) and the non-switched side going to the filament string (usually a pin on a tube socket). The idea behind this was that if you switched the radio off, there would be no voltage on the chassis, regardless of how you had the plug oriented in the outlet. Of course, when you turned the unit on, that's when the 50/50 chance came into play. When installing the polarized plug, if you leave the wiring the same, you will be connecting the neutral to the switched side of the circuit. This will at least insure that the hot side does not go to the chassis, but when the unit is off, you still have mains voltage at the filament string. To make it totally safe, you must rewire the power switch to the filament string and then connect the hot side of the line cord to the switch. The neutral will then connect directly to chassis (or common/ground). This way, when the radio is switched off, there is no mains voltage anywhere in the radio except for the input of the power switch. This can be a bit confusing, when you first look at the schematic, so I will sometimes redraw the power input section of the schematic to better understand how it should be wired. Hope that helps.
Edaytime I wanted to understand or see one of your repairs ,I couldn't you jerk the camera from side to side,I want to learn from these videos and check out your hard work ,but if you look at the videos ,this old man can't keep up ,I not trying to pick on you ,honest ,but its hard to follow ,.
Its a very nice repair you do very good work .
Doesn't it totally defeat the purpose of a polarized plug if it is installed the opposite way around? Before the change you had 50% chance of plugging it in the wrong way and now it is 100%. What am I missing?
Most of these old radios were wired with the switched side of the power cord connected to chassis (or common/ground) and the non-switched side going to the filament string (usually a pin on a tube socket). The idea behind this was that if you switched the radio off, there would be no voltage on the chassis, regardless of how you had the plug oriented in the outlet. Of course, when you turned the unit on, that's when the 50/50 chance came into play. When installing the polarized plug, if you leave the wiring the same, you will be connecting the neutral to the switched side of the circuit. This will at least insure that the hot side does not go to the chassis, but when the unit is off, you still have mains voltage at the filament string. To make it totally safe, you must rewire the power switch to the filament string and then connect the hot side of the line cord to the switch. The neutral will then connect directly to chassis (or common/ground). This way, when the radio is switched off, there is no mains voltage anywhere in the radio except for the input of the power switch. This can be a bit confusing, when you first look at the schematic, so I will sometimes redraw the power input section of the schematic to better understand how it should be wired. Hope that helps.
Watch out!! It has those IF transformers that develop silver mica disease They usually develop smd when they are that old!!
Just clip the hot side of the plug with diagonal cutting pliers as far as the hole. Viola! Po;arizwd plug!
Edaytime I wanted to understand or see one of your repairs ,I couldn't you jerk the camera from side to side,I want to learn from these videos and check out your hard work ,but if you look at the videos ,this old man can't keep up ,I not trying to pick on you ,honest ,but its hard to follow ,.