The Supreme Diagnometer

[Steve Johnson]

Here's a Supreme Instruments 400A "Diagnometer".  It was designed as the only piece of test equipment a radio serviceman would need to carry on a service call.  This model is from 1928. It's service case also has compartments for tools, spare parts, and tubes.  Diagnometers generally contained the functions of tube testers, RF signal generators, voltage, ohm, and milliamp meters, and condenser testers.  There were several models manufactured from the late 1920s through the late 1930s.

Here is my collection of "Diagnometers": www.supremeinstruments.org/diagnometers.htm

[Jason]

Wow Steve, that piece of kit is amazing. It looks fantastic. What is the idea behind the woven wheel thing on the left? I want to get a vintage tube radio some day, there is something special about tubes even to the point that some of the most expensive audio equipment in the world uses them.

[Steve Johnson]

Its a type of spider web coil. It's actually the transmitting antenna for the RF signal generator section.  Just set the thing next to the radio and you can do an alignment.