Hammond PWDP13025 Johnson Viking 500 T-301 LV Power Transformer

PWDP13025 is the low-voltage power transformer (T-301) for the Johnson Viking 500, original part number 22.1266. Built from the Peter W. Dahl custom transformer files, it is aimed at amateur radio restorers and technicians returning a Johnson Viking 500 to service.

The series table lists a 115 VAC, 60 Hz, single-phase primary; the part drawing labels the primary (BLK-WHT, leads 1-2) as 120 V 60 Hz. Five center-tapped secondaries are provided, all rated CCS:

• S1: 960 VCT @ 200 mA (red leads 3-4-5 on the drawing)
• S2: 560 VCT @ 100 mA (black leads 6-7-8)
• S3: 6.4 VCT @ 9 A (drawing: 6.3 VCT @ 9.0 A, green leads 9-10-11)
• S4: 2.5 VCT @ 10 A with 10 kVDC insulation
• S5: 5.0 VCT @ 3 A

The transformer uses an EI-175 X 1.75 core, is listed as Style 5, and weighs approximately 12 lbs (shipping weight 12 lbs / 5.44 kg). All leads come out a minimum of 9 in, stripped 0.5 in. Hipot test levels on the drawing run from 1000 V up to 7000 V, 60 Hz for 1 second, depending on the winding pair.

PWDP13025 is REACH and RoHS compliant, and its drawing label is marked Made in Canada. As with other Peter W. Dahl designs, units are usually built to order, so confirm availability by phone or e-mail.