941-A

The General Radio 941-A Toroidal Transformer was introduced in Catalog M (1951) and remained available through Catalog S (1965).

The Type 941-A is toroidal wound matching transformer operating at audio to ultrasonic frequencies. This transformer is designed for use as an impedance-matching and bridging transformer in low-level 600 Ω communication circuits.

The table below summarizes the specifications and connections for the desired output impedance and frequency response.

Specifications

• Primary Impedance: 600 Ω
• Zero Signal Inductance: inner windings, in series, at least 5 henry; outer windings, in series, at least 20 henry
• Resistance: inner windings in series, 9 Ω; outer windings in series 34 Ω (approximately)
• Distortion: varies with power; <1% at 1.26 W, <.5% at 1 W, <.2% at .5 W, <.1% at 3m mW

Type 941-A Frequency and Impedance Ranges

Output Impedance	Frequency for 1 DB Drop	Flat Insertion Loss less than	Input Connections	Output Connections
9600 Ω	80 Hz - 100 kHz	0.3 dB	H4 & L1	H8 & L5
2400 Ω	20 Hz - 135 kHz	0.2 dB	H4 & L1	H8 & L5
2400 Ω	80 Hz - 340 kHz	0.2 dB	H4 & L1	H8 & L5
600 Ω	20 Hz - 200 kHz	0.1 dB	H4 & L1	H8 & L5
600 Ω	20 Hz - 200 kHz	0.3 dB	H8 & L5	H4 & L1
150 Ω	5 Hz - 50 kHz	0.3 dB	H8 & L5	H4 & L1
150 Ω	20 Hz - 200 kHz	0.3 dB	H8 & L5	H4 & L1
37.5 Ω	5 Hz - 50 kHz	0.3 dB	H8 & L5	H4 & L1

• H = High and L = Low for connection phasing

Links

• Experimenter September 1950 describing Type 941-A

Photos

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