By Chris Heavens, AR Modular RF
As a designer and manufacturer of RF amplifiers we have always been confident in telling our customers that the more power output you have, the "better" your communications link. Just what is "better" needs defining of course; but simplistically you can either "go farther" or "be heard better," sometimes both at once, all other things being equal. The question of just how much "better" is a lot harder to quantify.
Being heard better
Systematically, all system losses (propagation path loss, physical obstructions, coax and connector losses etc.) and antenna gains are all "reciprocal" and as such they affect both communication directions equally. However, additional transmit power affects only one end of the path, specifically the end of the path receiving the amplified signal. In many scenarios the portable location has less power than the base or vehicle mounted system. This is exactly the reason for needing a small portable amplifier system.