Hammond 260A 22VA 400V C.T. Universal Primary Plate Transformer

The 260A is the smallest unit in Hammond's 260 Series: a 22 VA plate and filament transformer with a 400V centre-tapped high voltage secondary and a single 6.3V C.T. filament winding at 1A. With a universal primary it fits preamps, small low-power tube circuits, test equipment and general replacement work on 100, 120, 220 or 240 VAC mains.

Construction is economical open frame, chassis mount, and the series is offered in two-hole channel bracket (figure #1) or four-hole (figure #2) styles. The 260A is drawn as figure #1, the two hole channel bracket style, with 0.187 in diameter mounting holes (listed as 0.19 in / 5 mm). Ordering-table dimensions are A 3.25 in (83 mm), B 2.00 in (51 mm), C 2.00 in (51 mm), D 2.81 in (71 mm). Leads are a minimum of 5" long, and the shipping weight is 1.34 lbs (0.61 kg).

The 260A includes a Faraday shield between the primary and secondary windings. This electrostatic shield reduces capacitive coupling from the primary, greatly attenuating higher frequency current coupling to the secondaries. The shield lead, the gray wire marked SH, should remain grounded to the mounting bracket and in turn to the chassis.

The universal primary has taps for 100, 120, 220 or 240 VAC at 50/60 Hz, and the units are designed to run with BOTH primary windings energized for maximum efficiency. The 260A is listed as REACH compliant and RoHS compliant.