YT / BVT Family? a. Hand Keyed variant M54- V89T,only null message format known M55 F x 6, 000 000,long zero, null message M56 1fig:5fig, long zero M57- UNDER RE-EVALUATION M58 ===3lt UNDER RE-EVALUATION M63 A2A M64- "= 3F 3F = 11111 5F, AR" M65- Ends "= = QRU QR...