Hammond 370KZ 218VA 500V CT Horizontal Plate & Filament Transformer

The 370KZ is a high voltage (plate) and filament power transformer from the 300 Series, rated 218VA. 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 2 separate filament windings.

The high voltage secondary is 500V C.T. @ 300 ma. RMS, with a 50 VAC bias tap on the high voltage secondary (with the C.T. grounded). The transformer also provides 2 filament windings: #1 5V C.T. @ 6A; #2 6.3V C.T. @ 6A. 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 370KZ 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 370KZ uses the horizontal ("Z") mounting style. Published dimensions are A 3.00 in (76 mm), B 3.75 in (95 mm), C 4.06 in (103 mm), D 2.59 in (66 mm), F 3.38 in (86 mm), G 1.81 in (46 mm), H 4.50 in (114 mm), J 3.75 in (95 mm). It is listed as REACH and RoHS compliant.