[Heatercathodeshort]

It was quite simple really. Most of the line output transformers were of fairly simple construction. It was easy enough to dismantle them leaving just the underwind and overwind complete with their formers to deal with.

I would mount the overwind on the coil winder, set the counter turns indicator to zero and literally pull of the winding off slowly. Care had to be taken, breaking the wire was to be avoided as it could be difficult to locate the new start! A baby Belling was used to melt any stubborn pitch or wax.

The same applied to the underwind [primary] easier because the wire is much thicker.

A micrometer was employed to gauge the wire diameter and interleaving tissue thickness. Turns per layer had to be counted. You had to get this spot on or the bobbin would not fit between the cores!

Notes and pictures of connections etc were drawn and listed in my 'rewind book'. [Ha ha!]

The overwind was often wound with Eureka resistance wire. Probably done to reduce capacity. It was not necessary to use this but it had to be remembered that the resistance would be much lower than compared with the makers service data.

When checking LOPTs it is pretty useless comparing resistance readings with makers data as one single shorting turn can damp the transformer to such as extent that the EHT voltage collapses.

Testing was usually carried out with an old Ekco T231 under working conditions. Most transformers could be tested with the very versatile Ekco but I seem to remember I also used a couple of other chassis for the self oscillating types.

95% of the transformers I rewound were from the period 1952-60. As I said earlier, most of them were run of the mill. Anything earlier such as the PYE B18T were being scrapped in large numbers and I must admit I don't think I had the skill to rewind such a messy beast. The sectionalized EHT winding in particular was very compact and I don't think the Douglas wavewind machine could have coped with such close spacing between the windings.

To give you some idea I have scanned a very tatty page from my rewind book together with the school boy jottings. Not sure what make the transformer is intended for. It has a fuse on the front panel. Probably an obscure Argosy or similar. John.