Specifications

Any legal-limit amplifier should always be operated on 240Vac mains.
Here is a list of the transformer voltage & current outputs of the secondary:
13.5Vac @ 4A. for the tube filaments.
7Vac for the 5Vdc regulated power supply.
50Vac for the 28Vdc regulated power supply.
1250 & 1785Vac for the High voltage power supply.
Hipersil® transformers were patented by Westinghouse Co. back in the 1930's, designed by
none-other than Nikola Tesla himself. The patent expired many years ago. Many
companies began making them after that.
These transformers, as well as all the power transformers ETO Alpha used in their
amplifiers were made by the company of Harold Johnson Co Inc. (Not Peter Dahl).
Recently, the Harold Johnson Company discontinued making transformers for
Alpha/Crosslink. Now, Peter Dahl provides all the transformers for them.
The old transformers were very expensive to produce, costing in the area of $800 each.
They are very efficient, and very durable.
The white rope across the top of the transformer is for lifting, and at 45 Lbs. You need it!
The large bundle of wires is the low voltage primary and secondary. The small bundle with
Teflon® tubing on them, is the HV secondary.
It is a wicked good transformer!
About the DC power supply
The 7Vac secondary is rectified and regulated to 5Vdc for the PIN diode T/R system. The
secondary of 50Vac is rectified and becomes 36Vdc, which is used for tube "cut-off" bias,
the same 36Vdc is also regulated at 28Vdc for all other control voltages.
The HV PS uses 1250Vac for the CW/Low voltage range, 1600Vdc at the output end. The
1785Vac is used for SSB/High voltage range, 2500Vdc at the HV PS output end.
The HV PS consists of a full-wave bridge rectifier, and (7) 220µF@450Vdc computer-grade
capacitors, for 50µF @ 3150Vdc.
A ground isolated relay (K-13) switches the transformer secondary for hi/lo HV selection.
Plate current is sampled for meter reading from the AC secondary line through a small
transformer (T-2), then rectified and sent to the digital control board. Plate over-current is
interrupted by relay (K-14), which disables the exciter keying line.