[Superscope]

I had time over this Weekend to give the 1936 Model 7 a thorough Test.

It is fully functional on Volts all the way up to 1000 Volts AC & DC!
and it's fully functional on AC & DC Current Ranges all the way up to 10 amps!

The only work I did was to clean the Q Knob Switch.

Resistance ranges were a bit of an issue, and I spent a few hours running
round in circles trying to diagnose an unstable reading.

Bearing in mind, the Historic importance of this Meter, I didn't want to attack
it with a soldering Iron unless absolutely necessary.

I'm not sure if a Schematic exists for a Model 7 of this age, but I can't help
but think that some of the resistance values are different from the later model 7's.
It was very diffiicult and not entirely sucessful in comparing this Meter with a
later Schematic.

I have settled on leaving the Meter fully functional except for the 10K Ohms
Range which has a sometimes unstable reading.
I believe this is either a dirty Range Select Switch Terminal, or the 3.6 Ohm/10K Range Switch.

As much as I want this Meter to be 100% functional, I don't want to risk invasive repairs.

It is 95% in complete spec, but it does drift out to 1.5% in a few places on DC.
The AC Ranges are all in spec surprisingly.
This really isn't bad for an 86 Year old Meter which has only had minimal cleaning.

Final points of note Summary:

1) Temperature Compensator is slightly more compact and neater in design.
No idea if it functions as well or worse than later versions.
2) Movement can be removed without first having to remove the compensator
3) Rotary Range Switches are the Model 4/5 style, not the familiar later Model 7/8/40 Style.
4) The ohms Board is perpendicular to the panel, and not placed between the Upper and lower Resistance Boards as in later versions. (See Photo).
5) The upper and Lower resistance Boards have bakelite noticably thinner than on later versions.
6) Protective Movement Rectifier is different to later Horseshoe Movement Rectifiers as found on the later 7 and Model 40's.
7) Battery Bay appears not to have Brass Terminal Strips for the 2 x 4.5 Volt Batteries.


Ian