You are sort of basing your conclusions on temporary results Dave. Hams are not involved in 11m skip, because they use 11m. BUT - you have to remember that best distance at any time is based on the science - so if there is no skip on 10m, their licence allows them to go lower in frequency - maybe to 20m, where that band might be open. many hams use prediction software that takes in data from all over the world and tells them what bands are open (as in propagation is good) and which bands are closed. If a band is closed, then it’s local signals only. You can chat regularly to somebody a long way away, up until the time things change - and then if the band is dead, your longer distance contact is gone.
You are really hung up on the local distance thing. This is set by height above ground in virtually every case. The question is what I mentioned - path loss. Is there a path between location 1 and location 2? You often mention portable CB - this has been really variable ever since they started to make them. The antennas are terrible - the transmitter is designed to accept very poor VSWR, but usually something gets out. If that something is good enough - all is well. A car to a base station will not have the same perfomance as a huge truck with wing mirror mount antenna to the base - because it is higher, less restricted by obstacles.
It is IMPOSSIBLE for anyone to say 4 Watts is X miles. RF dos not work like that. Just because you get 30 miles does not mean somebody else will. Received signal strength is the deciding factor - but things in between reduce signal. You could go to a perfectly flat area and wherever two stations set up, the best distance would be similar. The minute you add hills, or even different types of ground conditions it changes. You mentioned that only today you can get spots within California - well, something changed, didn’t it? Not the laws of physics.
You even have to be careful. An 8m J-pole for CB frequencies is huge, but sellers play games with the gain figures. One claims 5dB gain - but says compared to a dipole - gain figs compared to dipoles should always say dBd - but this doesn’t so probably is 5dBi - but a dipole is almost 3dBi so the little bit of extra gain over a dipole is stated a bit craftily, forgetting to join the two together in maths. So the J-pole might have 2dB difference from the dipole, and 2dB is only just detectable practically. They just play with numbers to make them sound better than they are. What is certain is the J-Pole has more gain than the 102 inch truck antenna. 102" being very close to a quarter wave. That quarter wave also relies on having a good ground plane - which on a truck or taxi you do not have.
In all your posts, you try to make hard and fast rules, but then generalise, and use your own experience to bolster up the mangled rules you’ve sort of produced. I’m old enough to remember Skippy on TV and at that time radio hams were laughing at their huge hand held radios that could work over vast distances when people were in trouble. Nothing has changed. Low power, poor antennas and distance are unreliable as a tool.
Last thing - the old regulations all over the world took into account feeder loss - squirt 10W down a bit of poor cable so there was only 4W at the antenna was one way to describe power rules, but now with much more handheld radio use, it’s more sensible to always just talk about power output at the socket. For me - power is pretty unimportant, but antennas very much the vital element. Many years back, I wanted to talk to a friend 5 miles away and an American voice kept calling me. My local friend was weaker than the American voice, because he was in Skylab - a great example of a great path - absolutely line of sight between him over Africa to me in the UK. He had just 1W - all NASA allowed him to use. Power is just not that vital. In fact many radio hams deliberately use very low power and can still talk around the world.
cab aka car.
Antenna. When go my HH50WXST i purchase a 52 inch.