[Joeztech]

Philco was not the only company that did strange things. I remember RCA televisions that had the audio output tube used as a dropping resistor for the B+ to the IF circuits. When the tube began to loose cathode emission the picture would gradually get less and less contrast until finally video sound and all would go. Of course tube testing would reveal the problem as would tube substitution. Then they also had a weird circuit in some of their radios that used one if the IF tubes as a phonograph amplifier stage when the band switch was placed in the phonograph function position. Most of these strange circuits were done with the goal of reduced cost, while still producing a product with good reproduction of audio and/or video signals. One of the less successful ideas that Philco had was the use of encapsulated RC networks in many of their televisions during the 1950s. It reduced cost, but the technology was not the best and many of them failed more quickly than had been expected. I imagine that a good number of technicians were challenged when they were asked to work one of the 3X-116 or 3X-690 models. The tube count was high in those sets and the motorized station change circuit was not easy for many to understand. They were great performing sets though.

Joe