Hammond PWDF13057 Heath SB-220/SB-221 Filament Replacement Transformer

PWDF13057 is a replacement filament transformer for the Heath SB-220 and SB-221 amplifiers. It is part of Hammond's PWDAHL Series, the transformers and chokes catalogued directly from the Peter W. Dahl files for amateur radio products, and is suited to owners and repair technicians rebuilding these Heath units.

The transformer has two secondaries: S1 provides 5.0 VCT @ 30A CCS and S2 provides 90 VAC @ 0.1A CCS. The primary is 120/240 VAC, 50/60 Hz, single phase, so it is listed for both 50 Hz and 60 Hz supplies, which the series notes flag as the marking to look for when 50 Hz operation is needed.

Construction uses an EI-137 x 1.375 core, listed as Style 5 on the series style sheet. The approximate weight is 6 lbs and the shipping weight is 6 lbs (2.72 kg). PWDF13057 is REACH compliant and RoHS compliant.

Most PWDAHL designs are built to order one at a time, and Hammond recommends confirming availability by phone or e-mail. Catalogue identifiers are UPC 623980240459 and UNSPSC 39121301.

Having both the 30A filament winding and the 90 VAC auxiliary winding on one transformer lets PWDF13057 take the place of the original filament transformer in the SB-220 or SB-221 without adding a separate low-current supply.