B&W TV Marconiphone VT161
Today, I tackled a mechanical repair that was needed. The slightly less than robust, shall we say, thinner plastic section of the channel change control had broken away from the thicker shaft of the knob. It is meant to grip the tuner shaft by the aid of a spring clip about it's circumference. I knew any attempt to glue the plastic back into place would be totally useless and it would break again upon channel change.
So, after some thinking, I decided to drill a slightly larger hole down into the much thicker section of the knob shaft to almost accomodate a brass insert taken from a chicken-head type of knob. I very carefully drilled a smaller hole in the side of the plastic shaft to allow the grub screw to fit. Then, I heated the brass insert just enough to soften the plastic as it was pushed slowly and gently into the larger hole.
Then, a hole had to be drilled in the fine tuning control shaft so as to allow access to the grub screw. Here, they can be seen about the tuner switch shaft.
Finally, the fitted control knobs with the cosmetic plastic end screw installed. Care had to be taken against pushing the brass insert too deep as this end screw would not sit flush to the knob otherwise. All in all, this took most of the afternoon with some careful measurements. I only had the one chance of getting it all correct. Naturally, access when the chassis is installed into the cabinet had to be considered and fortunately, this is ok.
This afternoon I cleaned the glass implosion guard and cabinet. It has come up rather well, despite being covered in brown nicotine. The chassis with CRT has been re-installed and for the first time in who know's how many years, the set is back to how it once was. It is indeed a very good performer and I can see why it probably remained in use well into the 70's.
Many of the 405 line only sets made in the late 50’s early 60’s were excellent performers, most of the early problems had been sorted out and components/valves had settled into decent items. When the obvious culprits, paper caps and a few carbon resistors sorted they can work very well.