Here's an Ampex fully shielded Octel Socket Bridging Transformer. These are used in
older high end recording consoles, mixers, commercial sound systems modular amplifiers
and various tape machines to isolate inputs and/or match impedances. DCR between
pins 4 & 8 (primary winding) is 1.36K, between 2 & 3 (secondary winding) 1.30K.
The Ampex catalog part number is 4580200-01.
I have 11 of these for sale.
Asking $35 each, or $300 for all 11. Price includes U.S. or APO shipping.