two  RCA model MI-12399 microphone input transformer with 9-pin socket.  We only tested the transformer with a multi-meter for resistance and checked for shorts.
RCA 
MI-12399 
Primary = 250 ohms 
Secondary = 50K ohms 

Meter Test Results:
Pins: Ohms

2 & 9 = 3.179K 
5 & 6 = 9.4 
5 & 8 = 20.3 
6 & 8 = 10.6 

I have pairs available if you want to buy a pair email me and I will list them in another listing