Hammond 106V 250 CT to 8 Ohm Output Audio Transformer, 1.5 W

The 106V is a 106 Series miniature output transformer with a 250 ohm centre-tapped primary and an 8 ohm secondary. The higher primary impedance suits output stages that cannot drive the 48 or 100 ohm models directly, while still delivering into an 8 ohm load from a PC board.

It is rated for 1500 mW output with 1 dB insertion loss and a -1 dB low frequency roll-off at 170 Hz, and the drawing specifies ±1.0dB from 170Hz to 20KHz at 20dBu. The primary is rated for up to 14 mA DC. DC resistance is 11 ohms primary and 0.7 ohms secondary (+/- 15%) in the ordering table; per pin the drawing shows 5.266 ohms (1-2), 5.350 ohms (2-4) and 0.660 ohms (5-8). Primary inductance is 331.5mH (2.925K ohms) and leakage inductance 1.815mH at 1V, 1KHz.

Construction is rugged black epoxy potting that produces a completely sealed unit able to withstand severe environmental conditions, including those of MIL-T-27 (Grade 5, Class S). Centre-tapped windings use a bifilar technique for balanced resistive and capacitive characteristics, and the series carries a peak working voltage rating of 200V. From the part drawing: 500V RMS dielectric strength, 105°C temperature class and 50,000 ft. maximum operating altitude.

It mounts directly to a printed circuit board on square pins (0.025" square typical); where a connection is not used, no pin exists. It is REACH and RoHS compliant. The mechanical outline is Figure 8; the drawing weight is 1.44 oz. and the shipping weight 0.09 lbs (0.04 kg).