[Elecraft] [K3] Speaker Plug

[Carl Clawson]

I could infer from this discussion that 3.5 mm and 1/8 inch are two
different types of connector but I find no evidence of that.

The terms are used interchangeably by manufacturers. Switchcraft, for
instance, titles their products as 3.5 mm but goes on to say "all products
are 1/8 inch." On their drawing you'll see the plug diameter given as 0.14
inch +/- 0.01. That's 3.56 mm +/- 0.25. They're also not cheap, but I
recently bought some to try as I too have found this type of connector to be
generally unreliable. The one that I went to the trouble of measuring showed
poor sleeve contact. Maybe it's a corrosion problem. Lightly polishing the
sleeve has helped with some of mine. Others remain incorrigible.

I have not been able to find any industry standard for these connectors.

73, Carl WS7L
K3 #486