[Elecraft] 19inch Racks - somewhat OT

[Craig Rairdin]

>From Wikipedia (www.wikipedia.org) the repository of all knowledge:

"A 19-inch rack is a standardized (EIA 310-D, IEC 60297 and DIN 41494 SC48D)
system for mounting various electronic modules in a "stack", or rack, 19
inches (482.6 mm) wide. Equipment designed to be placed in a rack is
typically described as rack-mount, a rack mounted system, a rack mount
chassis, subrack, or occasionally, simply shelf. The slang expression for a
subrack (generally 1U height) is "pizza box" due to the similarity in size
and shape.

"Because of their origin as mounting systems for railroad signaling relays,
they are still sometimes called relay racks, but the 19-inch rack format has
remained a constant while the technology that is mounted within it has
changed to completely different fields. This standard rack arrangement is
widely used throughout the telecommunication, computing, and entertainment
industries, as well as others."

Craig
NZ0R



-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Tom Skinner
Sent: Wednesday, December 27, 2006 9:09 AM
To: elecraft at mailman.qth.net
Subject: [Elecraft] 19inch Racks - somewhat OT


Good Morning Group,

I just have share this.

Before I retired from the Navy, I was serving with the Joint Chiefs of
Staff, as one of the assistants to the communications guru, one
particularily gruff vice admiral who I'm pretty sure coined the phrase
"lead, follow or get the hell out of the way", and liked to continually stir
whatever pot he happened to be in charge of at the time.

For whatever reason, he called me into his office, one day, and asked me if
the 19 inch rack panel was a standard or a tradition.  I had long since
learned not to ask him why he was curious, I just charged off to find out.

I uncovered countless references to 19" racks, and a lot of things which
specified it, but failed to find out anything about its genisus.  Since
failure was not an option, I reported that it had something to do with the
width of hatches on early submarines, but an original order - if one existed
- was lost in the fog of the past.  In any event, the 19 inch  "standard"
was so deeply ingrained in the military (and a good bit of civilian industry
as well) that it might as well have come down as the 11th commandment.

He grudently accepted my "findings", but continued to press the issue,
claiming that if services were going to continue to support 19" racks, there
needed to be a mil spec actually in place.  Thankfully I retired before
being thrown into that briar patch.

I have wondered, over the years, if I missed anything.  Does anyone REALLY
know whether or not the 19 inch is a "standard" or a tradition.

73,

Tom, KJ3D (apparently with too-little-else-to-worry-about-today)


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