When did tv sets becamed more relaible and why?

[JohnCT]

Originally Posted by Alex KL-1

(Now I posted on correct thread):
Only for amusing, I only imagine perhaps a tube-based TV with modern resistors, capacitors and flyback/coils, with nowadays better stable mains, if reliability will be better than in it's days. At least for audio products, with modern parts, I can only need to change tubes when the tube are with problem, and not a problem caused by a bad resistor or (paper) capacitor cooking the tube (in the bias circuits for example). Of course, TV have far more tubes and resulting heat, but even so... (only for illustrating the contribution of passive parts)

Most decent vacuum tube TVs in the 60s and 70s had plastic caps and at least some metal film resistors although I remember some memorable early SS Sylvania chassis that used carbon comp resistors as voltage dropping resistors used to feed low voltage transistors circuits (the resistors got hot, dropped in value, dumped beaucoup volts into low voltage circuits where mayhem would ensue). EDIT: Could have been a hybrid in the D series. In any case, the signal circuits were all SS even if the sweep was hollow state.

Flybacks certainly could have enjoyed modern construction with epoxy and silicone instead of wax, but you would still need large(ish) value high voltage electrolytics which would still be problematic even today given the hours they would run and (as you noted) the ambient tube generated heat they would need to live in.

With regard to mains, vacuum tube equipment is more tolerant that SS stuff to noise and voltage spikes.

A modern built tube TV would definitely be more reliable in many areas compared to vintage stuff, but I'm not sure just how much more reliable a "modern" vacuum tube TV would be.

John