Tweet
Found this old thing at the local recycling centre. (It had a tube chart attached, so I could quickly work out what the Heater rating was (2.4A))
Before I do the PT tests, I wanted to check a few qns (see attachment)
The lugs on the PT are fairly much as I have labelled them in the attached .jpg (I think).
I'm fairly certain that the two terminals adjacent to the "P" are the primary winding terminals. One on them is connected to the black mains cable, and the other end is connected to one side of the on/off switch.
1) Would I be correct in thinking the "S" terminal is the shield? - it is attached to the bottom L.H. terminal which (I think) is the other side of the heater winding, which is attached to the chassis ground.
2) The terminal (one up from the bottom L.H. side) which is adjacent to the 6.3V grounded terminal has one side of the mains cable and one side of the power switch connected to it. I guess this is just a floating terminal that isn't directly connected to any of the windings in the PT (until the power switch is connected)?
3) I am curious why there is a 1k 5W resistor between the "S" lug and the HT centre tap. Any ideas? (HT elevation?)
Before I do the PT tests, I wanted to check a few qns (see attachment)
The lugs on the PT are fairly much as I have labelled them in the attached .jpg (I think).
I'm fairly certain that the two terminals adjacent to the "P" are the primary winding terminals. One on them is connected to the black mains cable, and the other end is connected to one side of the on/off switch.
1) Would I be correct in thinking the "S" terminal is the shield? - it is attached to the bottom L.H. terminal which (I think) is the other side of the heater winding, which is attached to the chassis ground.
2) The terminal (one up from the bottom L.H. side) which is adjacent to the 6.3V grounded terminal has one side of the mains cable and one side of the power switch connected to it. I guess this is just a floating terminal that isn't directly connected to any of the windings in the PT (until the power switch is connected)?
3) I am curious why there is a 1k 5W resistor between the "S" lug and the HT centre tap. Any ideas? (HT elevation?)
Attached Files