Topband: RG6 coax questions

[Bill Wichers]

It would be best to do a test fit of the connectors before buying a
significant quantity. IME, the RG6 from the "real" manufacturers
(Commscope, Belden, etc.) tends to fit the connectors from the "real"
manufacturers (Thomas and Betts, Augat, etc...) without problems. The
coax you get at Home Depot and the like I've found sometimes deviates
significantly from what "right" is.

I have had the problem you mention with the quad shield cable and
connectors. Most likely the problem is that your connectors aren't quite
right for the specific cable you have. You may be able to make it work
by removing the second foil layer (the one between the braids, not the
one directly over the dielectric). Sometimes removing that foil will
allow enough extra room for the connector to seal properly when
installed. You really need to keep both layers of braid for the
connector to hold though so you shouldn't trim too much of the braid
away.

Also, to add to what another posted said about coax, there ARE some
standards but there are a lot more of them then you'd think. There are
currently three main types of RG6 that you are likely to encounter, from
a shielding perspective:

"Regular" RG6 which has a 40% braid (sometimes 60% on the better
grades), a "100%" foil shield which may or may not be bonded to the
inner dielectric, and an 18AWG CCS (CCS = Copper Clad Steel) center
conductor. There is also a variant with a solid copper (BC = Bare
Copper) center conductor that is intended for things that are remote
powered through the coax (like satellite dish LNBs). Any of these types
should fit most compression-type connectors that are for "RG6"

"Triple" shield RG6, which has, in inside-to-outside order, a 100% foil,
then a 60% (usually) braid, then another 100% foil shield. The center
conductor is 18AWG CCS. This cable will *sometimes* fit the compression
connectors for "Regular (i.e. "dual shield")" RG6, but it really needs
connectors intended for it. This cable is very commonly used for CATV
drops these days.

"Quad" shield RG6, which has, again in inside-to-outside order, a 100%
foil shield, then 60% braid, then another 100% foil, then a 40% braid.
The center conductor is normally 18AWG CCS. This cable needs compression
connectors intended for RG6-QUAD cable since it has a slightly larger
outside diameter than the other two common types. I personally normally
remove the second (outermost) foil before terminating since that second
foil layer is not bonded to anything and tends to bunch up in the
connectors when you compress them resulting in a poor connector-to-cable
seal.

Note that all of the above can be had with a PVC jacket, a PE
(Polyethylene jacket, which is the best type for most ham uses), and
sometimes a plenum jacket (plenum-rated cable will be smaller diameter,
have VERY POOR UV RESISTANCE and thus be bad outdoors, and it WON'T fit
ANY of the compression connectors I've seen!!!). The PVC and PE jackets
are approximately the same outside diameter and should fit most
compression connectors without problems. Most of the cable types can
also be ordered with different coverages of braid -- frequently up to
90+%), but I've listed the types I've found to be the most common. More
braid = fatter cable, and if the cable gets too big in diameter the
compression-type connectors will have problems with it.

There is also an "RG7" type cable that is being used for CATV drops in
some cases. It's slightly larger than RG6 and requires different
connectors. 

Also, there are TWO common types of compression connectors -- the "one
piece" style like the Ideal connectors, and the "two piece" style that
Thomas and Betts makes (also Augat, although I think Augat just rebrands
the T & B connectors). I have found the two-piece types can generally
work with a wider range of cable types than the one-piece kind, although
they are also more finicky so they take a bit more practice to properly
terminate. Note also that all the tools made for the one-piece style
SHOULD be able to terminate the two-piece style, but some of the tools
for the two-piece style connectors attach to the SIDE of the connector
when in use (using a groove in the connector) and those tools won't work
AT ALL with the one-piece connectors. 

The most important parameter for the cable in terms of getting it to
work properly with a compression connector is the OUTSIDE DIAMETER (OD)
of the cable. The connectors you have should provide a range of
acceptable ODs for the cable, and armed with that information you can go
out in search of cable and be able to buy some that you'll KNOW will
work with YOUR connectors. There really isn't any need to buy matched
cable and connectors from any specific source as it's not very difficult
to select the proper connectors for a given cable (or vice versa), as
long as you have the data sheets for both and those data sheets are easy
to get from the websites of all the major cable and connector
manufacturers.
 
In my own system, I usually get my cable from my cable supplier I use at
work (since I can get good pricing from them as I have about 20 year's
history buying from them :-), and I usually get the connectors from the
same place. Most of the wholesale suppliers will sell in small
quantities as "counter sales" (cash sales to people that don't have
accounts with them) -- but their version of "small" is the
"manufacturer's put-up" (normally 1,000 foot reels -- they won't
normally sell cut lengths). They will generally also have the proper
connectors for whatever cable they stock. You should be able to find a
local cable supplier in your area pretty easily.

    -Bill KB8WYP

> -----Original Message-----
> From: Ray Benny [mailto:rayn6vr at cableone.net]
> Sent: Wednesday, May 11, 2011 4:17 AM
> To: topband at contesting.com
> Subject: Topband: RG6 coax questions
[snip]
> I went to HD today and found an Ideal compression fitting for RG6 Quad
> cable
> that look like the right types, I think. It appears that the whole
body of
> this fitting gets pressed forward to the front.
> 
> I have several questions:
> 
> 1. Does it sound like the newer compression fitting are the right ones
for
> my cable? I'll try tmw, but I'd like someone input as to if I have the
> right
> parts.
> 
> 2. I could buy another 1000ft spool of the more common RG6, single
shield
> (foil) - single braid quite cheaply from a local salvage store. My
> question,
> is the double shield/braid that much better?
> 
> 3. I looked at the CommSpec web site but could not find F6SSVX, only
> F6SSVV.
> Are they the same coax?
> 
> 4. Is what I have, F6SSVX considered Quad cable (double foil, double
> braid)?
> 
> Tnx for your input.
> 
> Ray,
> N6VR
> Prescott, AZ
> _______________________________________________
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