[Arran]

I've gotten several of these sets. IIRC, I have two in working order at this point. Out of all of them, I've never run into a weak CRT. Apparently those were very high quality tubes.

Brenda;
  I think that Philco put a lot more thought and care into these Safari sets then they did with the Predictas, at least the first generation Predictas. They wanted to make a ground breaking portable and battery powered TV and simply did not want it to be known as a dud, so perhaps the went overboard on the quality side, like new gold plated transistors and such. Of course the fact that most of these spent most of their time in the closet rather then playing 12 hours a day 7 days a week helped the picture tubes live a long life. They must have sold quite well in spite of their price, it's surprising how many still turn up, and still working, without having been serviced.
Regards
Arran