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
| 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
