Early Color Television
Stromberg-Carlson K-1 1955 Sales Brochures
Courtesy of John Folsom
The photos below show the convergence and purity magnets on the K-1. The K-1 appears to use a magnetic (permanent magnet) adjustment of the purity unlike the RCA receivers (and their clones) with their electromagnetic purity coil with adjustment pot. This is the only 15-inch color set we have seen with this arrangement. Evidently, the K-1 purity magnet assembly is rotated with its knurled nut, and the entire assembly may be rotated about the CRT neck. There is a field neutralizing coil around the CRT face and an adjustment pot.
The three convergence magnets hinge up from the angle shown to an angle that is perfectly vertical into the tube neck. It appears they rotate on threaded screws into and out from the CRT neck. The Sams shows that the convergence magnets are flipped (rotated) up so they must approach or retreat perpendicularly into/from the CRT neck on their threads.
But, it would appear that the positions of the purity magnet assembly and the convergence magnet assembly on this CRT must be incorrectly interchanged. Remember, in the RCA assembly, the purity coil is at the front (toward the CRT bell) of the mu-metal cylinder assembly and the convergence magnets are back in the center of the mu-metal cylinder assembly toward the socket.
If anyone has a K-1 manual to confirm the positioning and adjustment of these assemblies on the K-1, or any information on this, please contact the musuem.
Photos courtesy of Ed Reitan