I have an RA-87 loop supply that I’d like to resurrect but am having difficulty with the DC loop power connectors.  They are Hubbell “Twist-Tite” female receptacles as seen in the attached photo.  The diameter across the outer edge of the prongs is exactly 5/8”.  I’m not a “Hubbell guy” … but I’m trying to learn!

 

TT 11-957 documents the RA-87 (see: https://archive.org/download/TM11-957/TM11-957.pdf), where Section V “Supplementary Data” references Stock No. 6Z7815, described as “Hubbell #9213 Twist-Tite”.