Radio-Lectric no. 420 template use? Wondering what this would be used for, found in a box with some radio rule circuit diagrams. Knob turns to loosen/tighten, all three metal pieces slide.

THE MICROEMIDGET

Set of metal tools. Tongs look to about two feet long. Includes files, tong with a point and fly nut to hold something, and what appears to be hole punches. : r/whatisthisthing

Computers—The machines we think with

Grid-leak detector - Wikipedia

Booksubjectradio hi-res stock photography and images - Page 16 - Alamy

Analsis de Circuitos by Jose LUis Ola - Issuu

A Practical Guide to 'Free-Energy' Devices

The Box Radio : 11 Steps - Instructables

2014 Tech study guide: schematics and components (part 1)