AntAltMike said:
When you check the connectors, make sure that the center conductor is at least flush to the end of the connector or maybe even protrudes beyond flush by a sixteenth of an inch or so. I recently was having intermittent problems with off-air antenna reception and when I checked the connector that went into the pre-amp, the center conductor was protruding about 3/16" or so, so I knew I'd find that at the other end, it was short, since it meant the center conductor had migrated about an eighth of an inch.
Please.
You are not trying to tell us that the center-conductor actually moved within the dielectric the full length of the cable, are you? The dielectric is all but bonded to the CC, for one thing, often literally so. Even if not bonded the amount of resistance to it moving independently is pretty formidable once the cable length gets over about an inch or so. All the Astro-Glide in the world wouldn't help.
Assuming this could be done, what moved it? Temp changes would act on the dielectric and CC nearly evenly, and even if they didn't the odds of the CC being able to move microscopically yet randomly only in one cumulative direction and not the other at every temp change are pretty small. That would be about as likely as the molecules of cream in your coffee all randomly migrating to one side of the cup. The physics just isn't there to support either of those things happening more than about once in a few billion years.
Back in the real world, there can be a number of reasons for a short CC. Having cut at least 10,000 F fittings over the decades myself long before I stopped counting, I can safely say that the second-largest reason is due to the person cutting the cable nicking the CC during the cut through the dielctric, the avoidance of which is a learned skill where you cut almost through the dielectric so that it actually has just a tiny bit close to the CC that is undisturbed, then you break that by pulling on the dielectric, never touching the CC with the cutting implement.
But lazy, tired, or unskilled workers can nick the CC in this process, and it eventually breaks off at that point.
Most of us were also trained to cut the CC for length by, as the last step, laying the Kleins against the body of the end of the fitting and cutting, which naturally leaves the CC exactly a 16th proud of the connector due to the chamfer of the beveled edges of the cutting surface. It's an easy way to get a consistent proper cut. It also makes mating the connector easy; insert the CC first, then you can engage the threads (if the CC is short, inserting the CC comes last in this process, in the dark, with no real confidence that it didn't just fold over instead).
But if you use a 3-in-1 cutter instead of using a knife (and an improperly set cutter can also nick the CC and/or cut it the wrong length) the CC length is pre-cut. If the fitting is not pushed on far enough before crimping, it can also be too short, and that is the chief reason you see short CCs.
The old-school method of using a knife is still the best for a number of reasons, but contractors have migrated to the 3-in-1 cutters because they are quick and more consistent despite the fact that method does not do as good a job, and you don't have to wait for new hires to build up the chops to cut a fitting properly, which can take a good couple of hundred failed tries before they really get the hang of it, even assuming they are that motivated in the first place. The cutter sort of takes much of the potential for human error out of the equation, but it adds some of its own in short CCs.
But you really have to have it recessed about a 1/4 inch or more before it becomes problematic, because the female F is designed with teeth that grab anything within a 1/16 of an inch from its end, meaning even a short CC usually is not really short enough to be an issue; there is a lot of margin for error.
But your advice is still well-taken.
I'm still curious how a long CC on one end of a cable portends a short one on the other. As we all know, length is important. Some like a little more length than others, and if one end is a little long, it usually means the guy who cut both ends left the other end a little long as well.
