'Non-standard' standard plugs and sockets

[stevehertz]

I'm sure this is an issue that has affected many of us. I'm talking about so called standard plugs and sockets that are difficult to mate from different manufacturers.

My first one is the outside diameter of later 'high quality' phono plugs. Due to their extra width you cannot insert a pair side by side into the stereo pairs of phono sockets on the back of earlier receivers, amps and tuners. I have got around it in the past by using a sharp blade to take a shaving off the rubber shroud of the plugs, but you cannot do that if it's metal.

I have also found discrepancy between the outside dimensions of figure of eight mains plugs. On a Grundig Satellit 650, it would only accept the smaller size of plug that I had in my collection. Well, you could force the wider one in but it wasn't really the right thing to do.

1/4 'Jack' plugs and sockets also vary in their insertion depth whereby some plugs won't insert far enough to 'locate' in some sockets. I've also had jack plugs that are too thick (very tight) to insert into a socket.

What others?

[G6Tanuki]

There was a very-nearly-but-not-quite-compatible version of the classic Cinch-Jones plug, made by Painton. I once ordered a batch of these and only got to find out my mistake _after_ the bench-tech had spent an afternoon soldering a bunch of them to 12-core cable.

Also, the SO239/PL259 coaxial connector: there are 2 versions of this, one with the proper thread and another [briefly popular on some 1980s Japanese CB/ham-radio accessories like SWR-meters] whose threads are Metric. They're sufficiently-similar-but-sufficuently-different that you can screw the locking ring up six or seven turns before the threads jam and you need a pipe-wrench to ge tthe damned thing apart again.

Often caused by imperial/metric conversions losing the odd digit.

[emeritus]

I have had a similar problem with what ought to be standard 5/8 - 27 UNS threaded microphone stand accessories. Some seem to have been 5/8 - 26 TPI brass thread and so would only engage by a few turns before binding. This was a couple of decades ago with some Maplin items.

[Richard_FM]

I remember having a mains adaptor that would catch the switch on one of the power sockets in my old bedroom at my parents house.

More recently I had some F - Belling Lee adaptors that needed careful handling to screw properly onto the F connectors.

[cmjones01]

This is an annoyingly similar-but-different pair. At the top, the Amphenol 160 series, used on Tektronix 500 series scope plugins. At the bottom, the McMurdo "Red Range", which is easier to find on this side of the Atlantic and which is sufficiently similar to be confused with the Amphenol until you put them side by side. Just when you think you've found exactly the part you need for that extension cable or repair...no you haven't. They don't fit each other.

Chris