Hammond 145F 600CT:200CT Ohm Driver Audio Transformer, Chassis Mount

The 145F is a small open-frame audio driver transformer with a 600 ohm center-tapped primary and a 200 ohm center-tapped secondary, supplied 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. Because both the primary and the secondary are center-tapped, the 145F is wired to schematic 4 of the series sheet, unlike the other 145 drivers in this range that use schematic 2. It is also rated for the highest primary D.C. current of the 145 drivers listed here, 20 mA, with a primary D.C. resistance of 45 ohms and a secondary of 9 ohms (both +/- 15%). 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 145F 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.