Esoteric Patchbay Question for Old-Timers...

[Gregg Juke]

I have no current need to know this info, I just want to. Anybody who's ever seen what I'm about to describe can feel free to take a crack at an answer:

Years ago when I worked in radio (it was the 80's, and we probably had a fair amount of equipment from the 60's and 70's), we had a big patchbay in the control room. It _wasn't_ any of the following-- 1/4 inch, XLR, RCA, or TT (at least not like any I've seen since then). It was my first introduction to what a patch panel is and does, so I didn't know that it was "odd;" I just figured that they all looked that way. Anyway, what it was, was a larger than TT and smaller than 1/4 inch patch panel, and even though lots of stuff was running mono, all of the patch cords were these molded double-pronged plugs; each one looked like an old electrical plug, but with what looked like two 1/4 inch TS connectors, only they were smaller than 1/4 inch...

Sigh... Does anybody know what I'm talking about?

If so-- What kind of patch panel was that? And where is Bob O. when you need an audio history answer like that??

GJ

[leigh]

The studio at my college had that same style, I think. Was it sized such that you could jam a standard 1/4" cable in there, but you could tell that the connectors inside weren't happy about it?

[The Scum]

Longframe 1/4"?

Old phone company standard. Looks like TT, but it's 1/4" diameter.

[Gregg Juke]

Thanks guys; yeah Scum, I have one of those longframe 1/4 inch cables from somewhere, and wondered what the heck that was too.

But I think this was different. I _think_ (it was a long time ago) that the ends were smaller than 1/4 inch, but bigger than TT, and the unique aspect was the "double-plug" connector on each end of the patch cords (with rows of corresponding double inputs on the bay). But it definitely looked like something that Ma Bell or the military might have used, so maybe it was some kind of surplus telecom patchbay? None of the pictures of GPO/B-Guage/Longframe cables I've been able to find look like what I'm talking about, but if I get some time today, I'll check over at the Hinton Instruments website to see if I can find anything there.

GJ

[Dominick Costanzo]

Switchcraft catalog describes them as
"mil-type 1/4" twin phone"

jack model MT388
http://www.digikey.com/product-detail/e ... ND/1290212
plug model 411
http://www.digikey.com/product-detail/e ... ND/1290749
panel model 2400
http://www.connectors.kr/pdf/Switchcraft/204-205.PDF

Tip of one side was the + signal
Tip of the other side was the - signal
Sleeve of both sides was the shield

One side of the plastic casing was ridged to identify signal polarity.
If you wanted to invert polarity you just plugged one side of the patch cable with the ridged side to the left and the other side of the cable with the ridge to the right.

Panels had jacks arranged in pairs with a slightly larger space between pairs.
The highest density panels had 24 channels (48 jacks) on a 1 rack unit panel - 2 rows of 12 pairs.

several pictures here
http://www.coutant.org/old/

These were everywhere before the late 1960's and continued to be used in new installations well into the seventies.

Here's a pic of Record Plant NYC control room A in the mid '70's
http://media.soundonsound.com/sos/jun09 ... cks_02.jpg
Two 6' high racks were needed for the patchbay of the 30 input SpectraSonics console and 16 track tape recorder.

Here's a pic of Columbia Records LA studio circa 1966
http://biffbampop.files.wordpress.com/2 ... rianw4.jpg
Three 30" high racks held the patchbay for a 24 input console with an 8 track tape machine.

[Dominick Costanzo]

With these plugs and jacks, both hi and lo contacts are made at the same time, making it an excellent patching system for microphone lines with phantom power.
Higher density than XLR's 24 jacks on a 2.125" tall panel

[calaverasgrandes]

we have TT jackpanels with the twinned connectors at the TV station I work for.

[Gregg Juke]

Thanks Dominick, that's it!
Good primer on that type of patching too. Awesome pictures.
Thanks everyone.


GJ

[Dominick Costanzo]

One in action at the end of the clip - Larry Storch lives!
https://www.youtube.com/watch?v=jGwSgk5U0Zk