Hammond 844A 10K/40K Push-Pull Plate to Line Audio Transformer

The 844A is a broadcast-quality 800A Series output transformer for push-pull (P.P.) plates to line, with a higher primary impedance than the 841A and 842A. The primary is a nominal 10K/40K ohms (12K/48K ohms also listed) and the secondary 125/500 ohms (150/600 ohms also listed), for higher-impedance plate circuits driving a line.

The "**" note on this model in the series table means a single plate requires parallel feed. The maximum primary D.C. unbalanced current is listed as 0. Frequency response is +/- 0.5 dB max. from 50 Hz to 15 kHz, insertion loss is approximately 1 dB, and the maximum power level is +20 dBm with the specified characteristics, or higher with reduced low frequency performance. Along with the 841A and 842A, it is one of the three 800A models rated at +20 dBm rather than +15 dBm.

Humbucking construction helps reject stray magnetic fields, and balanced split windings on both primary and secondary give circuit versatility; the primary may be used as the secondary and vice versa for impedance matching.

It is housed in a deep-drawn steel case with a tin plated finish and fastens with two 6-32 mounting studs, supplied with hardware. Connections are made by wire leads of at least 4" in length. Maximum overall dimensions are 1.75" (44.5 mm) wide x 1.25" (31.8 mm) deep x 2.56" (65 mm) high. The 844A is RoHS and REACH compliant. Its listed shipping weight is 0.6 lbs (0.27 kg), and it is identified by UNSPSC 39121301.