Hammond 148Q 10000 Ohm Driver Audio Transformer, 75 mW PCB Mount

The 148Q is a compact open frame driver transformer for printed circuit boards, matching a 10000 ohm primary to a 500/2000 ohm secondary. It suits engineers and repair technicians who need a small interstage or driver coupling transformer in low-level audio circuits, where a high-impedance stage must drive a lower-impedance load.

Like every unit in the 148 Series, it uses an economical, open type, horizontal bracket construction with pin-type terminals (0.25" length and 0.025" square) for P.C. board mounting. The windings are bifilar wound for balanced capacitive and resistance characteristics on pin bobbins that suit a standard 0.2" grid, and each unit is insulation tested at 250V rms. Pins are not labeled on the part; a dot marks pin 1 and the remaining pins follow the schematic figure.

Rated output is 75 mW with a maximum primary D.C. current of 4.1 mA. D.C. resistance is 1700 ohms on the primary and 238 ohms on the secondary (+/- 15%, total winding). Frequency response is 200 Hz to 15 kHz (+/- 1 dB, referenced at 1 kHz) and insertion loss is less than 1/2 dB, while total distortion is approximately 2% at 200 Hz for drivers, decreasing at higher frequencies. The dual secondary value (500/2000) gives two impedance options from the same part; wiring follows schematic figure 2.

Net weight is 0.6 oz. (148 Series) and the listed shipping weight is 0.05 lbs (0.02 kg). The 148Q is RoHS and REACH compliant, UPC 623980198200.