I spent two hours today reading how 6/12v vibrators were designed for car/marine use. I graduated from a 4 yr electronics curriculum (impressed? it was a new vocational school) in 1960. I worked with tube technology for years. Anyway, this fellow has been collecting old books and scanning them and these books are available at his website: Technical books online There are a rich selection of older technology books there, communications, power supplies, etc. I hope you have as much fun there as I have today. GB
Oh that is really sweet! Thanks for posting those! I have been looking for some useful stuff like that to download.
If I remember correctly, usually the first digit or first two digits in the tube number had to do with the filament voltage. So a 12AX7 required 12 volts for the filament and a 6AU6 required 6 volts, while a 35C5 required 35 volts, etc. I seem to remember a lot of the older "el cheapo" models of TV sets often had all the tube filaments wired in series, and the tube filament voltages were selected such that they added up to 117 volts. Maybe I'm dreaming on that one but it sounded like a pretty shaky way to wire tube filaments. It would make for a cheaper transformer because it didn't require a filament winding (s), only the high voltage winding.
Working in my Dad's shop I was taught to feel for the vibrations before I looked any further when a car came in with an inoperative radio. AM was King then and the vibrator power supply was good enough for the poor acoustics of the day.
