Hammond 143N 10K to 2000CT Ohm Chassis Driver Audio Transformer

The 143N is a 143-146 Series driver transformer that pairs a 10000 ohm primary with a 2000 ohm center-tapped secondary. It is aimed at driver applications in chassis mounted audio equipment where a 5:1 impedance step and a center-tapped secondary are required.

The 143N is rated for 30 mW output with 1.5 mA primary D.C. current. D.C. resistance is 720 ohms on the primary and 89 ohms on the secondary, both +/- 15%.

Mechanically, the 143N 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 623980191409).