08-06-2016, 10:43 AM
Yes you are missing the 7Y4, it's the low voltage rectifier. The connector has been changed the except a pl-259 connector (very common connector). Most vtvm would have a length of shielded cable or coax with a 1 meg resistor in series with the center conductor going to the tip of the probe. The black connector takes a banana type or pin type connector. The banana is a bit fatter, hard to tell from the pic.
RS used to carry these parts and still may I haven't been to one in a while.
The HV probe is going to take a little guess wurk. Most have a resistors inside the drop the voltage down before it gets to the meter. Your has a large resistor connected to the connector on the backside. When you get it working try measuring a relatively small voltage with it without any resistance in series and see what kind of reading you get. HV probes are big and look like a turkey baster with wires.
RS used to carry these parts and still may I haven't been to one in a while.
The HV probe is going to take a little guess wurk. Most have a resistors inside the drop the voltage down before it gets to the meter. Your has a large resistor connected to the connector on the backside. When you get it working try measuring a relatively small voltage with it without any resistance in series and see what kind of reading you get. HV probes are big and look like a turkey baster with wires.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
