keywords - RCA, rca, microphone, ribbon, service, restoration, repair, factory, authorized, genuine, sales, parts, oem, specs, specifications, resource, diaphragm, lapel, velocity, mic, test, testing, reconditioning, recondition, 4010, 4048, 88a, 6206, 6207, 11001, kb-2c, 11013, kb-2c, 11013, bk-6a, 2199, 4043, 3043, 3044, 4001, 4025, 44a, 4026, 44b, 4027, 44b, 4027, 44bx, 4030, 50a, 4035, 74a, 4036, 74b, 4040, 77a, 4042, 77b, 12039, sk-39, 11017, 12002, kb-2a, 12003, kb-2b, 12018, 12035, 12046, 4043, 4044, 4045, 6203, 6204, 10001, 10002, 10006a1, 11005, 11006, 1007, 11010, 11019, 12034, 11042, 11048, sk-35, sk-46, kn-1a, 77b1, 77dx, ku-3a, bk-4a, bk-1, bk-5b, bk-11, sk-50, bk-14, bk-16a, 11024, bk-12