On Friday, 15 March 2019 11:09:55 UTC, Terry Casey wrote:
In article 63cdacc4-2fb5-4e8f-8432-098591ca6b19
@googlegroups.com, tabbypurr says...

I've not encountered a lot of connectors on the appliance, but IMLE they mostly failed.
Some had bare pins sticking out, though a lot were as you say shrouded. Shrouded connectors were frequently touchable live when part-way in.

I spent 9 years repairing radios and TVs from 1960 - 69, so
saw a wide variety of sets dating back to the early/mid 50s
from numerous manufacturers and never saw a set with exposed
pins. The connectors were all variants of a 5A 2 pin flex
connector, which is exactly what we used on the bench - the
manufacturers special version never left the customer's home.

There was a variant we occasionally saw, a polarised connector
with one standard size pin and one thin pin but a length of
matchstick in the appropriate hole of the female bench
connector resolved that problem!

By the end of the 60s, all manufacturers had moved away from
the detachable mains lead concept and new sets had integral
leads.

50s TVs were the first things I tried to repair, but mostly my experience has been with anything other than TVs. Largely various audio stuff.

Bulgins were usually unscrewable without a tool, so require a mod to stop that

H yes, the Bulgin P73 and P74 and the later miniature P360 - I
remember them well! What form does the mod take?

It's a long time since I even saw a Bulgin. A small screw somewhere stops it unscrewing by hand, but I don't recall just where the screw went, other than through the plastic thread.

I've seen tons of old mains connectors that lacked an effective cordgrip. It's a frequent problem

Yes, I can recall a number of plugs that were expected to be
fitted with cables much thicker that thin twin flex that left
a lot to be desired!

yes, and a lot with what are perhaps best described as unsuccessful attempts at cordgrips.


Fit felt washer, cut one if necessary. A soft epoxy resin over the set screw.

I was thinking of a drop of molten candle wax!

not robust enough


Fair enough. I have, on very rare occasions, come across knobs
with a short plastic grub screw fitted on top of the metal
screw but I doubt you could find them these days and, of
course, they would need BA threads!

Thinking about it, the knobs must have been specially made too
as you wouldn't normally expect to find a threaded hole in the
plastic part.

Turns out it's quite practical to duplicate old knobs now. Silicone to make a mould + resin.


NT