[radiotvnut]

Hi, I have 3 GE tubes (6CA4, 6BQ5, 12AV6) with a date code of 188-21 stamped on them. Can someone tell me how to read this particular type of date code? These came from an Audiotronics 300C classroom phonograph that I'm trying to date. The serial number is 184501.

I also have a couple of later model GE tube radios that use similar date codes on the tubes. One of the radios has a transistorized tuner and the rest is tubes.

Thanks for your help,
Bryan