HP 9810 A transformer

[wojtek]

You have taken it out of the 9810 so the checking should be simple, just connect it to the power source without any load (but with the fuze of course) and see what will happen :-) From the picture it looks like two sections' windings each with taps so the 765 should be on secondary section and 1234 on the primary, so the shortcut should be OK