Dumb question time - tapped choke

[thoglette]

I have a pair of large, three terminal chokes. Now I'm going to use them for a choke input supply to generate B+ for a PP2A3 amp.

I'm trying to recall how the tap on the chokes might be used. I've read it somewhere but can't find it in my notes anywhere.

For the parts mavens, they are marked R.T. 103 with terminal 1, 2 and M About 1kg in weight, steel case but not hermtically sealed

Thog

[AndrewT]

are all 3 taps on the same winding?
measure the resistance between the 3 terminals. Which pair gives the highest resistance?
Does the other terminal to each of it's partners give resistances that add up to that highest resistance?

[thoglette]

Originally Posted by AndrewT

are all 3 taps on the same winding?

Apparently not - 64 ohms between two, >1M to the third. So it appears to be a conventional choke.

There's a little "E" printed next to the third so I presume it's for earth.

Although it is not connected to the can or mounting lugs.