What set will last the longest?

[Penthode]

The RCAs from the kcs28 started using DC ideo amplifier coupling. This means that the DC component remains and a separate DC restorer is not necessary. The result is a better amplifier frequency-phase response and the pictures on these sets are amazing.

From the kcs45, the design went back to the DC restorer. The design was cheapened: the peak sync AGC amplifier disappeared and the AGC became cheap with simply a rectifier. Less sync amplification and the sync take off was after the contrast control to make up for the lost gain. Lastly, a high impedance horizontal deflection coil to match the horizontal output tube was introduced which was bad news.

From the kcs66 was an improved design. I like especially the return to DC video coupling and the introduction of keyed AGC to reduce airplane flutter.

From the kcs66, RCA had a wider range of sets from the very good to the pretty bad. The kcs 28 to the kcs 42 were all good.

Terry