I just put together a complete spare NOS tube set (14 tubes) for my SX-111. It's interesting the manufacturers I ended up with: Tung-Sol-(2) Sylvania-(2) RCA-(2) Westinghouse-(2) International Raytheon Truetone PhilipsECG Coronado CBS Together in a box, they make for an colorful pattern. 73, Skip Magnuson W7WGM