Hammond 106Q 48 CT to 3.2 Ohm Output Audio Transformer, 1.5 W

The 106Q is a miniature output transformer from the 106 Series that matches a 48 ohm centre-tapped primary to a 3.2 ohm secondary. It is aimed at small audio power stages, such as push-pull outputs, that need to drive a low-impedance load from a PC board without a bulky chassis-mount part.

It is rated for 1500 mW output, the top of the series range, with 1 dB insertion loss and a -1 dB low frequency roll-off at 170 Hz. The drawing gives a frequency response of ±1.0dB from 170Hz to 20KHz at 20dBu. The primary accepts up to 32 mA DC. Table DC resistance is 2.4 ohms primary and 0.3 ohms secondary (+/- 15%); per pin, the drawing lists 1.162 ohms (pins 1-2), 1.142 ohms (pins 2-4) and 0.260 ohms (pins 5-8). Primary inductance is 63.23mH (591.5 ohms impedance) and leakage inductance 338uH, measured 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 part drawing adds a 500V RMS dielectric strength, a 105°C temperature class and a maximum operating altitude of 50,000 ft.

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 106Q follows drawing Figure 8, weighs 1.44 oz. per the drawing, and has a listed shipping weight of 0.09 lbs (0.04 kg).