Hammond 260M 248VA 700V C.T. Universal Primary Plate Transformer

The 260M is the highest-rated unit in the 260 Series at 248 VA, with a 700V centre-tapped high voltage secondary at 288 mA, a 5V filament winding at 3A and a 6.3V C.T. filament winding at 5A. It is aimed at tube amplifier and test-equipment builders who need the most plate current in this family, on a universal 100, 120, 220 or 240 VAC, 50/60 Hz primary.

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 260M is drawn as figure #2, the four hole mounting style, with 0.22 x 0.56 in (6 x 14 mm) mounting slots. Ordering-table dimensions are A 4.50 in (114 mm), B 3.25 in (83 mm), C 3.75 in (95 mm), D 3.75 in (95 mm) and E 3.00 in (76 mm). Leads are a minimum of 5" long, and the shipping weight is 8.65 lbs (3.92 kg).

The 260M 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 260M is listed as REACH compliant and RoHS compliant.