On Sat, 11 Feb 2012 08:02:37 -0800 (PST), JIMMIE
wrote:
Sorry Jeff but I never used my connectors to support my cables. You
may be right but completely irrelevant to me.
Umm... you've never tripped over a cable, had the equipment fall off
the table with the cables attached, run RG6a/u up a pole to where it
has to support its own weight, moved furniture with cables still
attached, flexed the connector when used as a test lead, pulled cable
through the wall or conduit with connectors attached, etc? These are
all very common situations which will stress the connector to cable
connection. While it might not be a problem for a fixed (stapled in
place) installation, it certainly will be a problem for the average
home user.
http://802.11junk.com/jeffl/pics/drivel/slides/mess01.html
I find it odd that outdoor CATV uses quad shielded cable to prevent RF
leakage and ingress, and having the cable swept to perfection, while
you recommend using inferior F connectors.
To me F connector and
good connection shouldn't even be used in the same sentence. They are
what that are, cheap connectors at best that uses the center conductor
of the cable for a contact. Now that is Yech.
I do have some issues with RG6a/u that uses copper plated steel core
center wire. Mostly, it's a corrosion problem for outdoor connections
where the home owner does their own wiring, and uses F connectors
without the necessary rubber o-ring needed for waterproofing. I've
swept F connectors on the bench and find them quite good and often
superior to the rare 75 ohm TNC and BNC connectors near the top end
(2GHz for satellite). Incidentally, most of the antennas (that
survived a recent storm) on my roof use RG6a/u coax. The mismatch
loss between 50 and 75 ohms is minimal. Some use F connectors, but
most use BNC's made for RG6a/u.
Heat shrink has nothing
to do with the pull test or hiding poor workmanship but it does help
keep corrosion down which is the biggest problem with F connectors.
Ahem. I worked for a marine radio company during the 1970's. I
learned a few things about waterproofing and corrosion. Heat shrink
doesn't work. Capillary action along the heat shrink to connector
boundary will suck the water into the connector.
What I use (when needed) is a layer of 1" PTFE tape (or 1/2" if that's
all I can find) over the connector. Once in place, a layer of Scotch
66 or other electrical tape to hold it in place. The PTFE will cold
flow into the irregularities on the connector surface, and there will
be zero capillary action. If I want UV resistance, I spray the tape
with clear Krlyon (acrylic) spray.
While we're on the topic, I've experimented with various allegedly
waterproof enclosures and packages. The only ones I consider
genuinely waterproof are sealed and pressurized with dry air. Anything
less will eventually leak.
Ive never seen one pull apart except in the shoddiest of
installations.
I have and all too often. I was at the neighbors trying to
troubleshoot their Comcast cable tv and modem mess. They had some
friend of theirs do the wiring. All the F connectors were crimp ring
type and were falling apart. The coax was mostly RG-59 with maybe 80%
coverage. I replaced the most disgusting and will finish the job when
I have time.
One of the best things I have found to insure you
maintain a good connection is to apply something like DeOxit to the
connectors when you assemble them. Best done while all the parts are
new.
DeOxit and Cramolin contain oleic acid, which will slightly corrode
copper. It's good for CLEANING connectors by removing the oxides, but
should not be left on the connector. If you want to make sure that
you can take the connector apart after the threads rot in place due to
galvanic action between the aluminum receptacle, and the nickel plated
crimp type F connector, some silicon or lithium grease would probably
be better.
Some notes on the contents:
http://www.antiqueradios.com/forums/viewtopic.php?t=82058&start=40&sid=71ca160c8f60768 6916a0f355e9ecc34
Jimmie
As for special tools, I love them. My various cable preparation tools
for various coax cable have saved me countless hours of fumbling with
a pocket knife and diagonal cutters. Using the various compression
tools on F connectors almost guarantee a good connection, unless I did
something dumb. Same with crimp lugs, various LMR-xxx coax cables,
and Anderson Power Pole connectors. The days of using a hammer or
vice grips to crimp a connector are over. The cost can be
substantial, but is well worth it if you work with connectors
regularly.
http://802.11junk.com/jeffl/antennas/Misc/slides/crimpers.html
About $35/ea.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558