TEC S-505
The TEC (Television Equipment Corp.) model S-505 is a somewhat unusual booster. Its styling is certainly distinctive: a low, footed metal cabinet with a brown crackle finish and two small bakelite knobs, and a decorative metal band across its back and sides. It has three tubes: two 6AK5s, and a 12AT7. The circuit is a semi-broadband type, using a grounded-grid triode into a low-noise pentode stage, with a selector between the high and low TV bands. There is no fine-tuning control, but it does have a gain control. A large power transformer provides voltages for the tubes, through a selenium rectifier.
This booster was on my WANTED! list for a very long time. The presumably earlier model S-504 is still making itself scarce. Information about the company that made them is even rarer. If you know anything about TEC, please let me know!
Updated December 31, 2009