It should be noted that "loss" figures are all published by the
manufacturers, or in amateur publications, but are not controlled nor
maintained, nor even listed, in the governing military specification
MIL-C-17.
To find the loss of a piece of cable, that piece should be measured.
-WB2WIK/6
"If everything seems under control, you're just not going fast enough." -
Mario Andretti
> -----Original Message-----
> From: Bob Nielsen [SMTP:nielsen@oz.net]
> Sent: Monday, October 21, 2002 10:07 PM
> To: towertalk@contesting.com
> Subject: Re: [Towertalk] LMR400 vs. RG-213
>
> On Mon, Oct 21, 2002 at 11:17:33PM -0500, Jon Ogden wrote:
> > on 10/21/02 9:32 PM, Bob Nielsen at nielsen@oz.net wrote:
> >
> > > RG-213 has a non-contaminating jacket, not a direct burial jacket. As
> > > I recall it is practically identical to one of the RG-8 versions and I
> > > would expect that the loss figures are identical. In this respect, I
> > > am referring to what was once a MIL-spec cable, but the term "RG-8" is
> > > now applied to quite a few other cables in the .405 diameter class (as
> > > is also the case with RG-6, RG-58 and RG-59, etc.)
> >
> > There seems to be a lot of disagreement on this "direct burial" thing.
> My
> > RG-213 says it clearly on the jacket: "Direct Burial"
> >
> > No, there's no goop in there, but according to what I have been told by
> the
> > folks at Cable Experts (where I got the cable), anything with a
> polyethelene
> > jacket is essentially capable of direct burial. PVC jackets such as
> RG-8,
> > are not rated for such. I will double check my information with them
> since
> > they are in my area and I regularly pick stuff up from them.
> >
> > RG-213 is a mil-spec cable yes. It has a different dielectric than
> RG-8.
> > RG-8 typically has a foam dielectric. Has less loss than RG-213 but
> can't
> > handle the power.
>
> It IS confusing.
>
> MIL-SPEC RG-8/U had a polyethylene dielectric, the same as MIL-SPEC
> RG-213. I recall that the original had a contaminating PVC jacket, but
> I think there was a later version which had a non-contaminating PVC
> jacket. Accoding to the Belden catalog (which agrees with my
> recollection,) MIL-C-17 RG-213 has a non-contaminating polyvinyl
> chloride jacket, not polyethylene.
>
> RG-8 was replaced by RG-213 in the mil-specs back (I think it was in
> the late 50's or 60's), just as RG-9 was replaced by RG-214 and RG-55
> was replaced by RG-223, etc.
>
> Currently, cables which meet Mil-C-17 have a M17/xxx designation,
> instead of (or in addition to) an RG- number. Many manufacturers have
> (unfortunately, IMHO) applied RG designations to variations which are
> sometimes quite different than the original RG designation signified.
> This doesn't mean that they are inferior cables (quite often they have
> significant improvements), but not all RG-xxx cables with the same
> number are equivalent.
>
> 73,
> Bob Nielsen, N7XY
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