Shorted '72 HB1 repair.

[Knash]

This '72 HB1 had a short so I planned on sending it out to Tom Brantley. (He's done all my rewinds for over 20 years.) But I decided to take a chance and take it apart and got lucky to find a pinched signal wire.
The round slugs, in a square hole, are interesting as I recall square ones in the past.

 

[SFIV1967]

Are they really round? Or just the top of the square pole pieces is round?

GAD posted those two pictures in his blog and the top also seems to look round but the pole pieces are square below:

Ralf

 

[Knash]

Ah that's it. Thanks. I've seen the bobbins before they were installed and noticed the square shape then.

 

[GGJaguar]

...the top also seems to look round but the pole pieces are square

Maybe the square slugs are part of the HB-1 "magic".