This part is a kind of semiconductor called GT3005.
Function of this product has (GT3005 - GT3030) DATA BUS INTERFACE PULSE TRANSFORMER.
Manufacturers : MPS
Image and pinout :
Some of the text within the PDF file :
DATA BUS INTERFACE PULSE TRANSFORMER • Meets MIL-STD-1553 applications • Single ratio (see schematic), thru-hole package • Level T - for high reliability critical military applications • Also available in Level C and M (see website) • Package A is 4-lead; package B is 6-lead (center tap) Summary Performance Specifications Impedance Droop Overshoot Common Mode Reject (CME) Frequency Range (no load) Operating Temperature Range Weight Insulation Resistance Dielectirc Withstanding Voltage MPS PART NUMBER GT3005 GT3006 GT3007 GT3008 GT3009 GT3028 GT3029 GT3030 • Applicable specifications: MIL-STD-1553B MIL-STD-202 ISO 9001:2000 (see talbel below) 20% ±1V Max 45dB 75kHz to 1 MHz -55°C to 130 °C 5grams 10K MW@250Vdc 100Vrms TURNS RATIOS ±3% Pri: Sec 1CT : 1.41CT 1CT : 1CT 1CT : [ ... ]