D-shell connector age?
ard at p850ug1.demon.co.uk
Wed Jan 3 16:56:00 CST 2007
> Anyone know where D-shell connectors first appeared on equipment?
Earlier than you might think. I would guess 1950's/early 1960s. I've got
bits of navigational equipment, stuffed full of valves, and they have D
connectors on the modules.
They were certainly around long before the horrible SCART plug!
> Interesting thread going on in a local group at the moment about why SCART 
> sockets are so horrible and nasty (prone to breaking pins, difficult to line
> up, prone to falling out etc.) and why something better, like a D-shell
> connector, wasn't chosen instead.
Well, the D connector is not really an RF connector (yes, there are
versions with coaxial connector inserts, when did those come out?). Mind
you, the SCART connecotr is not exactly constnat impedance either!
> Thing is, SCART was apparently first used in consumer A/V equipment in 1977,
> which probably means it was thought up in the mid-70's. Edge connectors and/or
> circular DIN connectors were probably more common on computer equipment of
> that time, but were D-shell types around by then too?
Well, for home comuputers, maybe (the DIN connector , another horrible
thing, beaten only by the mini-DIN IMHO, was not at all common on larger
machines . But the DB25 was already well-established for RS232 serial
connections at that point.
 I don't know the date of that either, but Philips had DIN connectors
on tape recoerders in the mid 1960s.
[An aside. Am I the only person here to rememebr the IEC record player
connector? It's a flat thing with 5 flat pins on 0.2" (IIRC) centres, no
overal shroud round the pins like a DIN plug. The pins are arranged
something like :
-- -- | -- |
Every other pin is ground, the other 2 are left and right audio inputs.
Oh yes, the pins are called P, Q, R, S, T for some totally unknown reason.
A couple of my old Philps tape recorders have such a socket on them for
the record player input (wired in parallel with a DIN socket,
thankfully!). I have also found _one_ plug in my overstocked junk box. No
idea where you'd get more of them now. ]
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