[BULK] - rant on "mil spec" wasRE: [BULK] - [TowerTalk] RG-11Source?

Wed Feb 9 16:59:43 EST 2005

I'd suspect that the 2x,3x, or 4x shielding is one reason why we don't have nearly the TVI problems 
today that we had when I was starting out in the 50's and 60's. So bless 'em for that alone.

73,  Jerry K3BZ

----- Original Message ----- 
From: "Steve Katz" <stevek at jmr.com>
To: "'Jim Lux'" <jimlux at earthlink.net>; <TowerTalk at contesting.com>
Sent: Wednesday, February 09, 2005 2:42 PM
Subject: RE: [BULK] - rant on "mil spec" wasRE: [BULK] - [TowerTalk] RG-11Source?

> Hi Jim,
>
> Good rant.
>
> I have mil-spec (MIL-C-17/6B imprinted) RG11/U on spools in my garage.  I'm
> trying to remember the mill, probably Carol or Times.  It's not very new,
> I've had it several years, probably mfd in 1990 or so; but, it's unused and
> has been stored in a dark, dry environment so is "new."
>
> Nothing special about the mil spec other than it's solid PE dielectric with
> real copper conductors, unlike a lot of commercial equivalents (which may
> actually be better in some ways) that are cellular PE, or have clad aluminum
> conductors and other stuff.  The mil-spec stuff is more mechanically robust
> by design and materials used; doesn't make it better for our purposes, and
> probably makes it a whole lot worse for CATV use.  For CATV, the quad
> shielded RG6 the cable companies use blows away RG11/U in just about every
> respect, including cost.
>
> That's why when I heard the application, I recommended against using RG11/U.
> The "thick net" cables used commercially nowadays are better in every way I
> can think of except mechanical strength.  The old solid poly stuff is
> stronger, in that you can drive a car over it and it still works.
>
> 73!
>
> Steve WB2WIK/6
>
> -----Original Message-----
> From: Jim Lux [mailto:jimlux at earthlink.net]
> Sent: Wednesday, February 09, 2005 10:51 AM
> To: TowerTalk at contesting.com
> Subject: [BULK] - rant on "mil spec" wasRE: [BULK] - [TowerTalk] RG-11
> Source?
>
>
> At 09:19 AM 2/9/2005, Steve Katz wrote:
>
>>Tower Talkians,
>>
>>Anyone have a good source for quality RG-11?
>>
>>::I have mil-spec RG11/U on spools.  How much do you need?
>
> I don't want to beat up on Steve here, but he triggered an area near and
> dear to my everyday work.
> Just a quibble here about the term mil-spec... (a similar phenomenon occurs
> with high rel electronic parts, except there, it's with reference to 883B,
> Class S, etc.)
>
> There's nothing special about mil-spec stuff. It just means that someone,
> somewhere who had to buy something for the government wrote a spec, got it
> approved, etc. For instance, MIL-P-43988 is the 10 page mil-spec for toilet
> tissue in MRE-Packets (actually, it's been superseded by ASTM-D3905-1993,
> Toilet Tissue, Industrial). We also, of course, have to ask the question,
> "Whose military?"
>
> Of course, the military tends to buy things that can operate in harsh
> environments, so if you've picked the "right" mil-spec that might imply a
> better quality (or more appropriate) widget.  However, for some things, you
> might not want the mil-spec product: perhaps non-mil-spec Charmin might
> provide a better toilet tissue experience than ASTM D3905 compliant
> stuff?).  A good example is MIL-STD-810, which defines a variety of
> environments for equipment; Be aware that some of those environments are
> pretty benign, so claiming "meets MIL-STD-810" for your radio might not be
> all that impressive, however, some of those environments are pretty abusive
>
> One aspect of using industry standard designations (and that's
> fundamentally what a mil-spec is) is that there is the (legally
> enforceable) assumption that the product being sold has been tested or
> verified to comply with the spec. Here, we get into such fuzziness as
> "designed to meet".   The problem comes in about whether you can really
> sell something as complying with a specification that no longer exists
> (officially).  I couldn't do an electrical design for a client and claim
> it's "code compliant" if it met the 1981 NEC.
>
> And this is where the problem lies. There is no such thing as "mil-spec"
> RG-11 any more... Just like there's no such thing as mil spec RG-8, RG-213,
> etc. All the polyethylene insulated cables were purged 10 or more years ago.
>
> Back in August 1993:
> "
> CABLES, RADIO FREQUENCY, FLEXIBLE COAXIAL, 75 OHMS,M17/6-RG11, UNARMORED,
> M17/6-RG12, ARMORED
> ..
> MIL-C-17/6B is inactive for new design. For new designs use specification,
> MIL-C-17/181B, Cables, Radio Frequency, Flexible, Coaxial, 75 Ohms,
> M17/181-00001 Unarmored, M17/181-00002 Armored.
>
> The Qualified Products List (QPL) associated with this inactive for new
> design specification will be maintained until acquisition of the product is
> no longer required whereupon the specification and the QPL will be canceled.
>
> "
>
> Not to say that you couldn't legitimately claim that you've got cable made
> to a particular obsolete spec.  Or, you could say, I'm selling coax with
> the following characteristics, and then have your own mfr spec that happens
> to copy the parts of MIL-C-17/xxx needed.
>
> And, you might use the (obsolete) RG number as a shorthand to illustrate
> the type of cable. i.e. "RG-8 type cable"  This is what Belden does...
> their cables are all made to Belden specs, and have specific Belden part
> #s, and they get identified as "Type 11 cable", meaning, looks a lot like
> what you used to buy as RG11, in terms of impedance and physical
> dimensions, but not in terms of much else.
>
>
> Jim, W6RMK
>
> (I'll be happy to send the 400kB Mil spec for TP to anyone who wants it...)
>
>
>
>
> _______________________________________________
>
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>
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>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather Stations", and 
> lot's more.  Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>
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