Hammond 302AX 198VA 600V CT 2A3 Tube Plate & Filament Transformer

The 302AX is a high voltage (plate) and filament power transformer from the 300 Series, rated 198VA. It is aimed at builders, restorers and OEM engineers designing vacuum tube equipment who need a single transformer to supply the B+ plate winding and 4 separate filament windings. It is one of the two models in the series designed specifically for a particular tube: the 302AX is intended for 2A3 tube designs, which is why it includes two 2.5V C.T. filament windings.

The high voltage secondary is 600V C.T. @ 230ma. RMS, with a 50 VAC bias tap on the high voltage secondary (with the C.T. grounded). The transformer also provides 4 filament windings: #1 2.5V C.T. @ 2.5A; #2 5V C.T. @ 3A; #3 6.3V C.T. @ 6A; #4 2.5V C.T. @ 2.5A. The universal primary accepts 100, 110, 120, 200, 220, 230 or 240 VAC at 50/60 Hz; the units are designed to operate with both primary windings engaged. The 302AX can be run full wave bridge or full wave C.T.

Construction follows the series design: a Faraday copper primary shield (internally grounded to the end bell) reduces capacitive coupling from the primary and attenuates higher frequency current coupling to the secondaries, and concentric winding gives low stray field and low noise. The black powder paint finish matches the 1650 series of output transformers. Units are hipot tested at 2,000 VAC and are CSA certified (209651).

The 302AX uses the vertical ("X") mounting style; its outline is dimension reference X13 in the series specification sheet. Shipping weight is 8.5 lbs (3.86 kg). It is listed as REACH and RoHS compliant.