[Alastair E]

The Teletons that we saw here were generally pretty reliable. I do remember the 17JZ8 on the 12 and 14" portables did give trouble--probably as they were run pretty hard in a color set.

The 19" sets used a 21LU8, a tube of twice the power ratings of the little JZ8, which didn't give problems as I recall--not that we ever saw many Teletons anyway! Sadly these larger bulbs are not interchangeable, even though pin/pin compatable as the triode-sections are different specs..

Although oddball the sets used top-quality parts, and were well made. The caps are Elna electrolytics or Suzuki oil-filled things, with a few polyprop films around

Nothing shows any burning/discoloration or stress around tube-bases etc, and all tubes are still a good tight fit in the sockets. The HOT in its tin-box on the right with the 3AT2 is a pretty large thing considering the size of set, with a heavily potted overwind.

Power-supply has a Mains-Transformer 'autoformer' style having a tapping at 117V for the tube series-heater string, and a small overwind giving 250V from the 230V input for the main +B. There's a couple of isolated 15V rails and the CRT heaters also from this trans.
In this set--All the tubes in this one were made by Toshiba, although I'll be replacing one or two with some American ones, as I pulled the top-cap off the HO valve, and have botch-repaired it just to keep the thing working. I'll probably replace the luma and CDA output valves as well as the 3AT2 EHT Rec. because I have low brightness--even though the CRT Tests good.

Not sure who made the CRT, The green label in the pictures above has long gone. You're right--The CRT is a low-focus type--but strangely has a razor-sharp picture, just its too dark--a fault I'm chasing slowly. I normally dislike those low-focus tubes, nearly always soft pictures....