On Tue, 9 Dec 2008 07:52:00 -0800 (PST), JIMMIE
wrote:
I dont have a problem with crimp on terminals just that where I work
someone has always borrowed the crimp tool just when I need it.
I know the problem. Tools are expensive. However, there are a
variety of cheap replacements that seem to work well for me:
http://802.11junk.com/jeffl/antennas/Misc/slides/crimpers.html
I have several sets of these that cover everything from RG-188 to
LMR-400 size coax. There's also one for LMR-600 but it was being
borrowed when I took the photo. (Yes, it came back eventually). I
think I paid about $35/ea for the tools in the photo. At that price,
spares are an option.
I
always have my trusty soldeing gun handy, no one wants to borrow it.
When I was working on the bench, I had my soldering iron bolted to a
large block of wood to discourage the borrowers. My biggest problem
was someone trading or outright stealing my Weller solder tips. I
kept my supply locked up and hidden.
For me one is as easy and works as well as the other.
I beg to differ. Many of my connector installs had to be done in the
field, usually at a mountain top repeater site or up on a tower. The
problem was that the wind would cool just about any soldering iron,
gun, or even a propane torch, sufficiently to cause problems. Same
with the USCG vessels, where the coax was snaked through the mast, and
the connector had to be crimped at the top in the field. The only
place where I would effectively solder a connector was inside a
building. I do recall one day on a tower, when I draped my jacket
over my head, and soldered some connector by flashlight, but I don't
recommend doing that.
The biggest
problem I have with the non crimp type is the shield is eventually
cut from the connector.
Agreed. I have the problem with my test cables. A good strain relief
is a big help at immobilizing the shield. Pomona jumper cables have
molded plastic strain relief's. I use clear shrink tube (so I can see
when things are starting to come apart). In general, it's nut much of
a problem as I have far more UG-88/u BNC plugs fall apart than the
crimped variety.
The ones at work that are disconnected weekly
for preventive maintenance have only lasted about 20 years before
needing the connectors replaced, BUMMER.
Weekly? 52 weeks per year times 20 years is over 1000 connector
cycles. That's quite a few. I suspect the ears on the BNC jacks will
also be worn. I'm not surprised that they're failing. I did some
Googling and found specs for UG-88/u connectors ranging from 500-1000
mating cycles. Methinks you're at the upper limit of the lifetime.
The crimp-on type are not
without their problems. I was doing an inspection after some equipment
installation and was able to pull the the ends off of 20 BNC
connectors. The inspection stopped at that point and the decision was
made to reaccomplish all of the connectors, about 200 of them. The
installer was not happy. The problem turned out to be a bad crimp
tool. Like the solder-ons if done properly they are both reliable
connections.
Bummer. At one employer, we had an Amp-o-lectric crimping machine.
Someone found that it was possible to mis-adjust the tool to produce
defective crimps and proceeded to explore the possibilities. I was
blessed with dozens of field failures and a recall because nobody had
thought to run a pull test on the crimped connections. Everyone
assumed the machine could do no wrong. However, that's the big
advantage of a crimped connection... it's consistent. I can't get
that kind of consistency from soldered connectors, especially those
done in the field.
Incidentally, I've seen more damage done by the razor blade coax
stripping tools, than by the crimping or soldering. One nick in a
solid center conductor and the center pin connection falls apart
inside the connector. I try to use a thermal wire stripper, but that
also takes some skill.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558