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Antenna “Gain” might reduce your S/N ratio, especially in the case of a directional antenna, because you will be receiving less noise and competing signals. But, it will not impact the signal strength of the desired signal. In the case of an omni directional antenna, the impact is really minor since you really don’t hear much fromdirectly overhead or below the antennna.

Antenna gain is selected based on the site and required coverage area. It is a total misconception that more gain is better. Depending on the antenna height and terrain you can do more damage then good with higher gain. Site engineering is an important part of any system, science and methodology will always provide the best results over what one may think. Unless you are stacking UHF Yagis you will gain nothing by phasing omni's together, you would be better off setting them up diversity using power dividers but this involves its own engineering and the proper test equipment. Co phasing omni's was and still is popular for 10 and 11 meter but that is HF AM not UHF. I currently have several DB-420, DB-411, DB-408, DB-404 and a single Sinclair SC329-HF2LDF in use at different sites both part 90 Commercial and GMRS. Each one selected for the installation and desired coverage. The antenna is the biggest factor in any radio system with the coax the second, trust the science. I have and still do see allot of people wasting money and being unhappy with system performance over bad antenna selection. Just my $.02 Corey

Trouble is most people dont understand what S/N ratio, insertion loss, return loss, impedance, noise floor, velocity factor etc even are. The Yagi example has noting to go with gain at all. I have shown countless people using calibrated industry standard equipment RX gain is nothing more then S/N. If you take a 3dB Yagi and a 18dB yagi, mount them in a fixed position at a fixed signal the uV level received by the test equipment is going to be the same. This is why filtering, pre-amps and attenuator's have a place. Simple really, a filter to reduce the S/N ratio and provide adjacent channel rejection, pre-amp to boost the signal and proper attenuation to lower the noise floor.

I guess everything I have ever learned is wrong, guess I should sell my Areoflex and Sitemaster.

Oh give them 20 years or so... If you are new to GMRS and radio all together.... keep in mind many who have been at this for years in all forms of radio have a "common sense" approach to things...goes with that "spirit" of the rule type deal. There are 20 guys a day that get into GMRS and think they have found some incredible new discovery in capability that no one else has thought of....but it isn't practical, isn't legal, and doesn't meet the common sense test.

That's about as close to a smoking gun as you're going to get from the FCC. They are aware that people are using surplus Part 90 equipment - and they don't intend to anything to stop that use. As others have mentioned, there's never been a single enforcement action by the FCC against anyone for using Part 90 equipment in Part 95. If you've been around the block with the FCC a few times, you begin to realize that many of the rules have been written after the fact.