[Chas]

How to dynamically test a radio power transformer:

Remove or disconnect the rectifier. Check filament and pilot circuits for short in particular pilot lamp sockets.

Power the radio, any transformer defect will be seen in moments and up to 30 minutes later. Crackling noises, heating, smoke are unrecoverable failures. For transformers with rectifier on top of the transformer any indication that the rectifier socket is failing make an inspection to be sure there is no short before testing.

If the transformer is relatively cool after 30 minutes it is fine.

GL

Chas