"A",
"B",
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
BNC: The Bayonet Navy Connector operates best at frequencies up to about 4 GHz; beyond that it tends to radiate electromagnetic energy. The BNC can accept flexible cables with diameters of up to 6.35 mm (0.25 in.) and characteristic impedance of 50 to 75 ohms. BNC connectors are the most commonly used connector for frequencies under 1 GHz. Frequency Range vs Connector Type
The BNC connector has an outer conductor [normally ground] and an inner conductor which normally carries the signal. A BNC connector is used with a Coax Cable [Manufacturers]. The SMA Connector is a similar style connector, but smaller.
Refer here for Coax Connector Manufacturers
