7. Modifying the mains transformer

A standard A22 has three tapping points on its mains transformer to select different voltage ranges, the A22T being an export set has an additional three. The body and size of the two types of transformer are identical, the A22T just has a much larger voltage selector panel fitted.

I couldn't replicate the additional three lower voltage windings, but I could replicate the appearance by making an appropriate reproduction A22T voltage selector fascia and fitting the existing A22 selector panel to its rear.

This would involve extending the existing wires between the transformer winding and the selector panel and rotating the selector itself from the horizontal and refitting vertically in the centre of the new fascia.

The reproduction voltage selector consisted of two parts, the existing paxolin panel which the tap selector was attached to and a graphic of the A22T selector fascia, printed and laminated several times to achieve an appropriate thickness, fitted in front.

The "U" shaped metal bracket that forms the front of the transformer, mounting the selector panel with two rivets, had to be fitted the opposite way around in order to provide the clearance required from the transformer windings.

The rivets were carefully released using a modellers drill and a burr tool. This enabled them to be reused to secure the new selector panel. Observant readers will note that they have been refitted a little lower and should actually be in-line with the middle voltage taps. This was a necessary compromise due to the "U" bracket used being approximately a quarter of an inch shorter in height than the one used in an original A22T.

Although not necessary in terms of making the set work, I felt the cosmetic modifications worthwhile. The voltage selector panel along with the dial are the only two things that visually differentiate the A22T from the A22, so I thought it important to try and reproduce them both for the sake of authenticity.