Z-Angle Meter 310-A

RF impedance bridge. At the balance the meter directly reads phase angle.

• Impedance range from 0.5 to 100.000 ohms
• Phase angle from -90 to 90 degrees
• Frequency range: 30 to 20.000 Hz
• Accuracy: 1% impedance, 2% phase

The 310A was first advertised in 1947. Early production used a couple of 6SJ7 in the RF input stages. From 1948 they were replaced by the RCA 'special red' 5693 types.

The Z-Angle Meter was designed by Luke Packard, who left General Radio to co-found the Technology Instruments Corporation.

The General Radio style in present in the shape of the set, in that of the meter, of the knobs and in every constructive details.

Here you find 4 models, 3 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Technology Instruments Corporation; Acton, MA