Need RFL 750 Gaussmeter schematic

[5065AGuru]

Hi, I'm working on an RFL 750 Gaussmeter. It is the early version with the battery compartment at the rear of the unit. When I power it up with AC supply selected I get no meter indication at all even when twiddling the pots on the front panel. I checked the power supply, it is a simple zener regulated supply at 19VDC and that checks good. Also checked the meter movement and it is also good. I need a schematic to figure out whats going on! Also wonder what batteries it used. There are three holders for cylindrical batteries in series and my guess that the batteries would be 6 volt units but can't what vintage battery was used.

Cheers,

Corby

[stevopedia]

Unfortunately RFL seems to be a very poorly-remembered manufacturer, in spite of the high quality and specialized nature of their instruments.

Magnetic Instrumentation (https://maginst.com/) wound up with RFL's gaussmeter line at some point. The only reason I know that is because we have (had?) some 912s at work that are marked RFL, and some marked Magnetic Instrumentation. I sent them a polite email asking for documentation and they sent me a scan of the operating manual and schematics. It may have helped that I wrote from my work email address. Either way, it can't hurt to ask

They apparently still offer new probes for models 750A and 750D, by the way!