I got it! I got it!

[tritwi]

According to what is on the brochure of the set, the tube has a sealed darkened glass on its faceplate. It doesn't seems a bonded type and it has not the classic yellow halo around the hedges. As we in Europe made wide use of push through picture tubes we had the need for tubes having the tube sides completely smooth. American tubes used to be placed inside a mask hiding corners.I heard about x rays issue on older tube type televisions but I think early color tvs all suffered from this kind of emission. Here in Europe there were mainly two kinds of horizontal and eht stages. One used a single horizontal/eht transformer and it also used a similar 6BK4 (PD500)tube to stabilize the hv. The other kind of circuit used separate horizontal and eht tranformers each with its proper driving tubes. This circuitry didn't need to use a high voltage stabilization tube. All this stuff was obviously put inside metal cages and the hv rectifier and ballast tube were commonly labeled with "x-ray" warning.
Gianni, I don't think simple pal was a flop, it was more a variant of NTSC. It is capable of good pictures. The main problem of the simple pal are the so called hannover bars that show up on particular colors such as yellow. Anyway who is
Argeo Deotto?
My Kuba portacolor has exactly the same chassis and picture tube as the Telefunken you mention but aesthetically it's quite similar to the original GE portacolor.