Universal Bridge LCR20

T.I.A. model LCR20 universal bridge is designed to measure inductance, capacitance and
resistance, generally to an accuracy of ±1%. It is self-contained, and transistorized, being powered by internal batteries. Provision is made to excite the bridge from its internal oscillator at 100Hz, 1kHz and 10kHz. For the measurement of resistance of reactive components (for instance, iron cored transformers), the bridge may be excited at d.c.
from internal batteries. The detector is a moving coil meter movement, preceded by a high gain amplifier. Automatic gain control is incorporated to facilitate balancing the bridge with inductors and capacitors of low power factor. At d.c. a transistor chopper is switched into the circuit to convert the amplifier to a sensitive d.c. detector. The bridge operates over the following ranges:-
 R: 1.9Ω to 1.9MΩ for d.c. (to 19MΩ for 100Hz a.c.)
 C: 19pF to 190µF
 L: 190µH to 1900H
 Q indication is: 0.01-1 at 100Hz
                        0.1-10 at 1kHz
                        1-100 at 10kHz
 Tan δ indication is: 0.001-0.1 at 1kHz
                             0.01-1 at 10kHz
An internal 4.5 volt polarizing voltage may be applied to electrolytic capacitors during testing.

Here you find 2 models, 2 with images and 1 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Thomas Industrial Automation Ltd.; Altrincham