Sal M. O'Nella wrote:

After I got out of the Navy, I worked as a Marine Electrician,
installing equipment on Navy ships. My foreman told me that it is
rarely done, but the Navy can perform a Quality Assurance "pull test" of
25 lbs on a connector. I think that's a lot of pull for a connector to
withstand.

In a previous life I was tasked with tailoring a large number of RG-58
cables connecting radar scopes at a new installation in Korea. This
involved cutting the cables to length and installing clamp and solder
type BNC connectors. The rumor was that the Korean troops were supposed
to be helping us, but we never saw them -- until one day, when they
showed up. The one assigned to help me sat down and, neither of us being
fluent in the other's language, I proceeded to show him how to assemble
the connector.

Now the job of one of the several pieces, a metal ring, is to push
against and expand a rubber washer, which is mainly what holds the
connector together. This piece looks like it should go upside down from
the correct orientation, but if put on that way, the rubber washer won't
expand and the connector will come off very easily, with only a gentle
tug. If assembled correctly, it'll take a lot of pulling, as Sal says,
to get it off. I've never seen a correctly assembled connector come off.

Getting back to the story, I carefully demonstrated the correct assembly
method to the Korean troop, emphasizing the orientation of the ring.
After putting the connector on, I showed him our standard test. We would
grab the connector in one hand and about two feet down the cable with
the other. Then we put our hands together, making a loop of cable, and
briskly yanked them apart, resulting in a really good sharp tug on the
connector. A properly assembled connector had no trouble with this test.

So I gave him the parts and went to work on a connector. After a while
he handed me the cable with attached connector. I gave it the tug test
and the connector snapped right off. So I repeated the mimed
instructions, with extra emphasis on the ring orientation, then put him
to work again and got back to what I was doing. When he was finished he
handed me the connector, I did the yank test, and again the connector
popped right off. He shrugged, muttered something under his breath, got
up, and left. Guess he figured he'd had enough of that game, where he
assembled connectors and I pulled them off. We never saw the Korean
troops again.

Roy Lewallen, W7EL

Roy Lewallen wrote in
:

I've never seen a correctly assembled connector come off.



Another story, but with a different outcome.

I worked in a training school at one stage, and we thought we would get
trainees to make up BNC RG58 patch cables as a practical exercise, and we
would feed the output into our satellite labs where cables didn't seem to
last long (trainees pulled equipment trolleys around by the coax if it
didn't reach the desired socket).

Total failure, the BNC field serviceable connectors were just too
complicated for dissinterested trainees more interested in discussing
fast cars than concentrating on the job... and they had no stake in it,
if the cables didn't work, it didn't matter too much.

Solving the problem of the connectors pulling off led me to the Amphenol
specs, and I found that the pull out spec for the field serviceable
connectors was *much* lower than the spec for the crimp connectors.

So, I bought a quality crimp tool (in those days, it was a few hundred
dollars), and some Kings crimp connectors, and we switched the classes to
use the crimp components and a trim jig. The outcome was much better,
fewer faulty cables, and the crimped cable retention was much better and
consistently so.

No I know that one of the large suppliers to hams advertises "crimped,
not soldered", but that is just a blatant case of playing to the market.
A bit like the single core 4:1 Guanella balun that manufacturers
attribute to Sevik's assurance that it will work fine on a fully floating
load... whan antenna system is a fully floating load. The theme is the
customer is always right, if he wants something that doesn't make sense,
see Rule 1.

An interesting new connector type is the "compression connectors", "Snap-
n-Seal" is a proprietary name. I tried some of these on RG6, and a bit
suspicious of the cable retention mechanism, every one I tested using
different types of RG6 (including QS), hung on until the cable tore apart
some distance from the connector.

Owen

Owen Duffy wrote in news:Xns9D9948E3052AFnonenowhere@
61.9.191.5:

No I know that one of the large suppliers to hams advertises "crimped,
not soldered", but that is just a blatant case of playing to the market.


Got that back the front, didn't I.

DXE advertises "soldered, not crimped", but that is just a blatant case of
playing to the market.

Owen