Hammond 106W 500 CT to 3.2 Ohm Output Audio Transformer, 1.5 W

The 106W is a 106 Series miniature output transformer with a 500 ohm centre-tapped primary, the highest in the series' output range, and a 3.2 ohm secondary. It is suited to low-current output stages that need a large step-down into a 3.2 ohm load on a PC board.

It is rated for 1500 mW with 1 dB insertion loss and a -1 dB low frequency roll-off at 170 Hz; the drawing gives ±1.0dB from 170Hz to 20KHz at 20dBu. Maximum primary DC is 10 mA. The ordering table lists 26 ohms primary and 0.3 ohms secondary DC resistance (+/- 15%); the drawing shows 12.64 ohms (pins 1-2), 12.60 ohms (pins 2-4) and 0.260 ohms (pins 5-8). Primary inductance across pins 1-4 is 545.8mH (4.596K ohms), with leakage inductance of 3.913mH 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. The drawing adds 500V RMS dielectric strength, a 105°C temperature class and a 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 106W follows mechanical Figure 8, weighs 1.44 oz. per the drawing and ships at 0.09 lbs (0.04 kg).