Hammond 145D 200K to 1000 Ohm Chassis Mount Input Audio Transformer

The 145D is an input audio transformer in the larger 145 body of the 143-146 Series, matching a 200K ohm primary to a 1000 ohm secondary. It is listed for input applications with very high impedance sources in chassis mounted audio equipment.

The 145D is rated for 10 mW output with 0.5 mA primary D.C. current. D.C. resistance is 3600 ohms on the primary and 33 ohms on the secondary, both +/- 15%.

Mechanically, the 145D is a small, economical open type transformer with a two hole horizontal bracket for chassis mounting and overall dimensions of 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). It uses insulated, color coded flexible leads at least 4" long, and net weight is 1.4 oz. Where a P.C. board mounted version of this style is needed, the manufacturer refers to the 148 and 149 series.

Frequency response is 150 Hz to 15 kHz within +/- 1 dB, referenced to 1000 Hz. The manufacturer notes that operating at impedances below nominal lowers power capability and frequency spectrum proportionately, while higher impedances raise them. It follows schematic 1 in the series table and is listed as RoHS and REACH compliant (UPC 623980193007).