Marconi, you raise a (several actually) good point(s) here...
. There is a thread below "Make Your Coax Invisible" that got me to thinking, but I'm not suggesting anything about amplifiers.
In the CB world I've heard many suggest the feed line length does not mater, period.
Which is this was the most ideal goal - which all should strive for - the connect tune and use approach is the least lossy and most IDEALISTIC goal one could obtain...
I've also heard folks say the feed line length does not matter, and then adding, if your match is off...re-tune your antenna.
Again, a wise choice for anyone - but the word here is
Feed-Line not coax...and also is the antennas own "appearance" and what it sees, at the location, and position - it is in. Feed point Impedance ...
I've also heard many say to make your feed line as short as possible, period.
This again, to re-iterate what the firstly boldly quoted phrase says, is the most efficient when you can provide for the antenna and counterpoise - but then to apply this properly, that is; if you can make the antenna not only exhibit the PROPER Impedance and use the proper coax that meets that impedance - then the issues of RESONANCE is the only thing that you - the operator, need to focus on.
I read manufactures recommend specific feed line lengths and multiples for their antenna kits.
Do you see it yet?
There is the "Urban Myth and Legend" about "How coax length does matter"...
In just the 4 statements you posted, and the 3-YT's of many more, there is the gauntlet of ways one could describe how a budding Radio enthusiast gets his desires and willingness to help - Get Shot down in flames only to burn in hell ...
With that being said, why would anyone - Social Media or otherwise, even want to discuss this?
Because there is confusion amongst the rank and file about what coax and feed line and the antenna and it's feedpoint impedance - these two aspects; coax and the antenna - at their connection point - as well as the how the cable from your radio "sees" what's is there, way back at the SWR meter - their interaction - is in some eyes, a miracle - while to others - a curse..
So the 4 main views of what is being said, I can see how people become confused by the 4 choices - (amongst the many) that are not really choices, but are descriptions of visual and physical results achieved by those that see the events you're talking about, from their perspective and apply the best explanation possible.
One type of antenna can use Ladder-line or simple 300-ohm lead in wire from an older TV antenna and with some patchwork quilting of coax - used as a balun - a little measurement, trim and setting...
Whammo - instant Antenna that is suitable for yard and clothes hanging and with some ingenuity - your name can be strung in cursive so that even satellites can view your house and if your Hi-po Miracle is radiating RF - the heating losses can be detected and the Local-TV stations' Weatherman,using the latest infra-Red satellite views, knows (shows) you're there!
Another example of the Opposite argument is to use an antenna designed - measured - built - to be made RESONATE and it's your responsibility to make a matching network (sound familiar - SEE: Balun) and hook it up.
- Between the two - I see a carborundrum - Bandwidth. You mentioned the need for long-wire antennas (160M?) that may or may-not be resonate - but you did post this in a CB Radio Forum...
Again - some type of matching is needed - let alone resonance - but again, if Feedpoint impedance was equal - then the operator only has to hook up the coax and become an instant smash hit of The-Man-Behind-The-Microphone - substitute Maniac for Man as needed...again, ones' idealistic goal...
I'm saving this for last because it's said to many - too many times - and yet remains one of the many reasons why random length is more of a moniker for - Use What Works For You...
I'm saving the best for last because it sums up nicely....
My old antenna mentor use to tell me to keep the feed line length at random lengths and avoid problems. He also said never make your feed line length a resonant length at your frequency of choice. In my limited understanding I never could determine his reasons for saying this...except for the idea that feed line length did not matter, if the antenna was tuned perfectly to a resistive match and was resonant. Back in those days for me, I never considered CMC an issue I could deal with.
Now the above raises even more questions let alone the establishment of a good - balance of common sense along with considerations of others in the local proximity of the radiator. So to handle CMC - as well as radiation resistance issues, that can jump ship and recouple back to a feedline, or coax - means we have more to do, to make the radiator more efficient, not just "better".
That's where the places like Tandy, Barjan, Wilson and Your Local Truck-Stop - to name a few, make efforts to manufacture radiators, coax and antenna mounting hardware to accommodate the environment these devices will be used in,. To make matching problems appear as a congruous variable that can be overcome to a certain degree if the operator is willing to accept lost efficiency and less effective radiation pattern in order to provide a low or more-tolerable SWR - meaning that they provide a radiator that is less-efficient, smaller size, manageable for ease-of-mounting to many locations (mostly Ferrous) - that has less radiation resistance - on top of greater losses in the matching network (or winds) and then (on top of) to use a coax that is 50-ohms.
But where it's connected at, in the base/mount of the antenna - REQUIRES the use of a SPECIFIC Length of coax, the Balun principle, is why these makers say do not trim off the coax. Because it is required for Low - SWR - See Owners Manual.
Taking a deep breath, because were not done yet!
From that - comes the issue of tuning the Radiator (aka Whip) to make the feedpoint where the coax is connected to on the mount, at the antennas location - altering it's feedpoint impedance to a range of tuning the Balun - aka COAX is more closely matching the 50 ohm impedance at the opposite end to the radio - and see a low SWR - it's not necessarily RESONANCE.
Again, looking at is from the perspective of the designs the antennas are - makes them less efficient radiators but more efficient in overcoming the environmental variables of comfortably using the radio with the coax (yes I said it) as a means of a Balun for the antenna SYSTEM.
We have considerable ohmic losses when it comes to the efficiency of said CB antenna systems.
I hope this clarifies my take on this subject...
