On Fri, 25 Sep 2009 23:44:44 +0100, Dave Plowman (News) wrote:
In article ,
Rich Grise wrote:
As far as the RCA plugs are concerned, the Red plug has long been
Right.

Pro gear doesn't use RCA plugs. But can use TRS.

Is "TRS" a mnemonic for something? All I can think of when I see it is
the Radio Shack/Tandy TRS-80, pronounced "Trash 80". ;-)

Tip ring sleeve. Unbalanced stereo or balanced mono. Or sometimes a mono
in and out on a mixer.

I'd guess originally designed for telephone exchanges. In the UK, the
telephone one is known as a type 316 and has a smaller tip than stereo
jack plugs. And is still in use - must have been designed over 100 years
ago. Dunno if the US one is the same.

Oh, yes - the US has been using "Tip & Ring" for about as long as there
have been telephone exchanges. (a hundred years?) :-)

My cousin Owen inherited Uncle Dick's farm - they still have a
wall-mounted crank-style phone with the separate earpiece similar to this:
http://youngandthewireless.com/empty..._telephone.jpg
[mind the wrap]
and they have an early phone book - most of the phone numbers were two
digits! (Circuit & phone). (it wasn't a very big town. ;-)

If you're curious, it's Lake Crystal, MN.

Cheers!
Rich