Gilles's point is well taken: when you're running an impedence mismatch, you are going to lose some signal. For some people, even a small gain is enough to pull out a signal where before they heard nothing but static. If you're trying to DX, then every dB you can get is important.
Even where I am, where mountains block 3 sides, I can get a marginal signal off of a couple of repeaters; a stronger, higher antenna with a better cable would bring out the signal just a little more. I'm going to take care of that soon.... a nice Diamond dual-band antenna on a 30' pole will do the trick; the only catch is that I have to run a longer feedline to get it at least 30' away from the corner of my house where the power lines come in.
The thing is, not everyone goes for DX or weak-signal work. The beautiful thing about repeater operation is that much of what I work can be worked with an HT on half-power. So if you're not working long distance stations, then you can use just about anything and get a signal... but don't be fooled in to thinking that RG6 is going to be better than using the right cable for the job. RG6 is great for TV, satellite, and FM radio, but it's not so good for scanners and 2-way radio.
I have hooked up a specific antenna with identical lenghts of RG58 and RG6 and can "ear" the difference. Over a broad range of frequencies the RG6 performs better. Better still would be a lower loss cable like LMR400. Especially when you get into the 800mhz range, the loss on RG58 will far outweigh any impedance match.
Did you try a length of RG-8? That's thicker stuff, and it ought to be a lot less lossy - especially on UHF.
As I posted in another thread, and has been posted here numerous times, RG-6 is fine for scanning applications.
Ahh, but is it
ideal?
