Hammond 260C 65VA 500V C.T. Universal Primary Plate Transformer

The 260C is a 65 VA plate and filament transformer with a 500V centre-tapped high voltage secondary at 85 mA, a 5V filament winding at 2A and a 6.3V C.T. filament winding at 2A. The 5V winding suits a rectifier tube heater while the 6.3V winding feeds signal-tube heaters, so one transformer covers a small tube amplifier or preamp supply 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 260C 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 4.03 in (102 mm), B 2.65 in (67 mm), C 2.62 in (67 mm), D 3.56 in (90 mm). Leads are a minimum of 5" long, and the shipping weight is 2.77 lbs (1.26 kg).

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