[Username1]

Funny thing your thinking about something me and a friend at college did years ago. The town I went to school in back in '89 had one Zenith and one RCA dealer on opposite ends of main street. I was taking some circuit design classes with the Zenith guy, and both of us were interested in the picture detail and clarity difference on the Zenith and RCA sets. At the time back when I knew all the design analysis math, the both of us set out to figure it out. What we found was in the circuits we put through the math, was that in the Zenith circuits they matched stage impedance better. Also what is commonly called "bounce" which is a minor second order response was higher in the Zenith sets. On a Square wave, bounce looks like overshoot on the transition edge of the square. On a lot of sets the Sharpness knob produces the same effect on screen when you watch the edge of white lettering that seems to have a dark trailing edge on crt sets. Now since we only did the math, and did not correct or rebuild, modify circuits all I can say is that the math seemed to indicate impedance matching, and since there was less picture detail and sharpness in the RCA I would say the mismatch was probably inductive. But this is all over 20 years ago from what I remember. Both sets were tube, and models we both had access to at the time.
The math involved reflected impedance through stages, and bode plots something I don't even remember how to start now a days..... Thinking about it now, I bet the RCA sets had more negative feedback to prevent the second order response. I bet now that there is a lot of computer based design analysis software, that this would be a good thing to explore. Old RCA tube manuals had a lot of the information in there to add the tube characteristics to the design software. You kinda have to think of the tube as a MOSFET because tubes are not current amps, a lot like the mosfet.