Hammond 143J 3000 to 1000CT Ohm Chassis Driver Audio Transformer

The 143J is a 143-146 Series driver transformer that matches a 3000 ohm primary to a 1000 ohm center-tapped secondary. It is designed for driver applications in chassis mounted audio equipment where a compact, bracket mounted part is preferred.

The 143J is rated for 30 mW output with 2.6 mA of primary D.C. current. D.C. resistance is 265 ohms on the primary and 53 ohms on the secondary, both +/- 15%.

Mechanically, the 143J is a small, economical open type transformer with a two hole horizontal bracket for chassis mounting and overall dimensions of A 1.26 in (32 mm), B 0.69 in (18 mm), C 0.69 in (18 mm) and D 1.06 in (27 mm). It uses insulated, color coded flexible leads at least 4" long, and net weight is 0.5 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 2 in the series table and is listed as RoHS and REACH compliant (UPC 623980191201).