RCA transformer ID 901855-501

gents,

Using the search function and the googles  I found info on an RCA trafo 901855-1 but have not found any info or specs for the 901855-501.  If anyone has info on this trafo or where it may be found I'd much appreciate it.  THey came out of a 1950's era modular RCA PA system used for mic preamps with a 12ay7 tube.  I have heard that RCA usually badged UTC trafos during this period but need more info.  The primary is red/blue with secondary as yellow/green with brown as ground and black as case shield.

Regards, Nathan

one of the most common industrial grade or PA systems inputs.  -501 is a revision #.    Possibly nothing more than paint change.  If uTC, it will also say UTC. 

I have a pair of these.  They measure out to about 150:50K.  I believe you may have the colors for pri and sec backwards