I tend to agree with Mike500, but I wouldn't make this just a sat. vs. CATV comparison. To me there seems to be a measurable difference between commercial grade and consumer grade coax cables (if those are meaningful category names for this discussion), even if only qualitatively, and that seems to apply for almost everything!
I used Tandy RG-6/U QS for some of my own installations, both sat. and OTA. In recent years I have come to realize that Tandy cable is a consumer-grade product, not in the same league as the better commercial grade cables. Some of that Tandy coax has been in service for 25 years and is still working well. It is certainly not the quality of "CATV cable", but it has held up. The sat. part was placed in service when ~1500MHz was all you needed for sat. service. It is still working well enough at ~2150MHz. I doubt this cable was ever "swept" to be certified for either range, but it works just fine over the lengths I use (50-75' runs). I did notice when I recently re-teminated a chunk of the cable that was carrying my OTA signal that the outer shield had a powdery white "dust" on it (aluminum oxide?) and I am concerned that I have evidence of a kind of break-down that is part of the life-limiting characteristic of this cheaper cable. I also have some very old chunks of CATV cable left over from one installation or another over the years. None of those show anything similar. The center conductor of the Tandy cable was well oxidized, but the CATV cable I have seems less so. Just things I have observed, and in the grand scheme may be insignificant.
There are other considerations here re: out-of-box quality and long-term reliability, both of which affect performance. I never did a "numbers" comparison (I'm not even sure where you could get those numbers for a lot of the cheaper stuff like the Tandy cable) but I'm willing to bet the the better cables have lower loss figures especially at the higher frequencies due to better dielectric materials, and that the shielding of the non-QS types is superior on the better cables as well vs. non-QS consumer-grade stuff. That would mean to me that for more sensitive OTA signals one should use the better cable types for best performance, initially and probably for the longer term. For DBS sat. signals, as long as the cable can pass the ~2150MHz signals with reasonably low loss over "typical" lengths (50-100'?) then the cable should be OK for that application, and even with a lower designed service life will likely be so for quite a few years. To be sure, the cable is ever degrading and probably at a quicker rate, but that degradation won't be noticeable in most installations. And for digital signals, the "quality" of the shield is a lot less significant for most installations. It would be more critical for analog applications, like legacy OTA and CATV service.
I too have collected a number of old electronic devices, like phones from the rotary dial age (still have 2 in service!) and tube-type radios, etc. Those were certainly designed to last for the long haul, vs. throw-away in a year or two, most likely due to obsolescence. When something has a designed service life of just a few years, that's a minimum (with some small expectation of "infant mortals") based on a stated set of conditions. Most of that item will last a lot longer, statistically speaking. Everything except a good wine degrades with advancing age. In some applications you just don't notice it.
Just my 2-cents worth. Cheaper may work in some applications. Better is always best...! YMMV
