[Arran]

The problem with these is not due to the 6X5 tube, in and of itself, it's the fact that they used a pair of them, and wired both diodes in the 6X5s in parallel in an attempt to get around the maximum current and voltage ratings, in a what would otherwise be a nine tube set with push pull 6V6 outputs. Why they did this is anyone's guess, maybe they thought that the design would make the transformer cheaper since it would eliminate the 5 volt rectifier winding? Or maybe they got a really good deal on a rail car full of 6X5Gs from Sylvania or one of their other suppliers. It was really a case of a bad power supply design, not that the 6X5 was a bad tube, they were used in thousands of small AC and car radios for years, but in most cases they were run at well below their maximum threshold which was 70 ma at 250 volts, and employed 6K6s rather then 6F6s or 6V6s. One easy way to tell if the transformer is bad is by Ohming out the windings, if one side of the high voltage winding is substantially lower then the other, shorted, or is open, the transformer is bad, an AC voltage check could tell your the same, but a resistance check is something you can do at the rectifier tube sockets without risking damage to the radio. By the way, the 10A1 is the chassis number, not the radio model number, which would be something like 10-S-566, depending one which cabinet style it had. Some of these sets also had a faux wood grain on parts of the cabinet, which is a bit of a turnoff for me, much more then a bad power transformer or 6X5 tubes,
Regards
Arran