Thermistor No. 1A, 1AN & 1A-1

It has a cold (20C) resistance of 200k ohms.
 

Thermistor No. 1AN
This is a Thermistor No 1A, mounted on a steel plate and fitted onto the chassis of a Telephone No. 312.
 

Thermistor No. 1A-1
This is a Thermistor No. 1A, encapsulated in black rubber with two, spade ended, fly leads.

Generally used on Party lines, when 700 type telephones are installed, to stop bell tinkle.

Drawings - 91451 and SD102.

Specification - D1887.

Last revised: January 19, 2023