Hammond 145L 4000:2600CT Ohm Driver Audio Transformer, Chassis Mount

The 145L is an open-frame audio driver transformer with a 4000 ohm primary and a 2600 ohm center-tapped secondary, carried on a two-hole horizontal bracket for chassis mounting. It belongs to the 143-146 Series of audio chassis-mount transformers and is intended for engineers, technicians and OEM builders who need a signal-level driver transformer between amplifier stages.

Electrically, it is rated for 135 mW output. The 2600 ohm ct secondary is the highest secondary impedance among the 145 drivers in this listing and has a D.C. resistance of 100 ohms; the primary measures 340 ohms (both +/- 15%) and is rated for 8 mA of D.C. current. The series specification sheet gives a frequency response of 150 Hz to 15 kHz (+/- 1 dB, reference 1000 Hz). When it operates at impedances below nominal, power capability and the frequency spectrum are proportionately lower; at higher impedances they are proportionately higher.

Construction is small, economical and open, with a two-hole horizontal mounting bracket. Leads are insulated, color-coded and flexible, at least 4 in long for the 145 Series. Overall dimensions from the series table are A 1.63 in (41 mm), B 0.88 in (22 mm), C 0.81 in (21 mm) and D 1.38 in (35 mm), and the series sheet gives a net weight of 1.4 oz for 145 Series parts.

The 145L is listed as RoHS compliant and REACH compliant. For a similar transformer designed for PC board mounting, the manufacturer refers to the 148 and 149 series.