Ahh, so basically, my units dont have enough ass to transmit the distance I want them to is what Im finding out. Apparently 0.5 FRS and 1.0 GMRS just doesnt make the range I need it to. So. . . Im thinking im going to put a few units up for sale and see about getting some of the new Rino 650's. Apparently they have 5x the transmit power on GMRS. 5 watts on gmrs sounds good if im reading this right. What do you guys think?
5 watts vs 1 will help you out for sure, with any type radio. I do know from my time as a ham that your antenna is as important as the power your putting out. You can run 1000 watts thru a peice of crap and not be able talk very far, where 5 watts with a good antenna design will allow for great comms.
OK here we go into teaching mode. Power is relatively irrelevant as BP has stated, all things being equal. what does matter is the antenna, it's position and the operating frequency. They try to claim 20 miles on the 5 watt units. the reality is that will only happen if you can see the other radio 20 miles away. These rigs are strictly line of sight and that means exactly what it sounds like. the frequency they operate on transmits in straight lines, the radio waves do not curve along the surface of the earth like lower frequencies do. so quite literally if the other radio is below the visual horizon of where you are using yours. you wont reach it. a better antenna will concentrate your transmitted power toward the horizon but will not over come this. a higher antenna may. Just like when you are up on the roof or in a tall building you can see further in the distance, because this changes your view of the horizon it does the same thing for radio waves. Also the type of antenna will concentrate the radio wave closer or farther to or from the horizon.
an Ideal antenna is referred to as an isotropic radiator. and while they really don't exist they are a model that is used to define antenna performance. An isotropic radiator would transmit it's energy in a perfect sphere, think of a beach ball, with the antenna going through the center. In the real world the radiation pattern is closer to a donut, flattened at the top and bottom. The better the antenna is the flatter the donut gets, so lets look at that beach ball again... push down on the top of it against the floor, the flatter it gets the wider it gets, the same thing with transmitter antennas. we want a nice flat donut for a radiating pattern. The problem is your hand, arm, head and body will affect the pattern and skew it so few antennas on the radio it self are very effective, but there are some tricks that can be used, like holding the radio up in the air and using a separate speaker mic, an antenna that isn't mounted on the radio, a device known as a tiger tail which is actually a part of the antenna the manufacturer didn't include because it is a dangling wire hanging off the radio (in specific the antenna's ground).
Now most people are used to using a term known as "s units" this comes from CB days. to give you an idea of how power relates to the received signal, S units are based on a scale from 1 to 9 and 9 plus (normally we would call it a scale of 1 to 10 but thats how it is referred to since anything over 9 is full scale and may actually be a signal stronger than ten but thats where the meter stops). if the person you are talking to is transmitting 1 watt and you are receiving them at a level of 1 they will have to increase their power by ten fold to make an increase of one unit at your position. Now they are transmitting 10 watts and you are receiving them at 2 units to increase it one more unit, they again have to increase their power by ten fold that means to make it up to 3 units at your end they need to xmit 100 watts, 4 units takes 1000 watts and so on, it is an exponential progression of power. So as you can see the single most important item is the antenna and it's position well beyond anything else.
Next we have to look at where you are, the terrain can physically block your signal. rock, concrete, metal and trees full of moisture, green wet vegetation all can block the signal as well. so really the only place you will get the full performance out of a hand held radio with an antenna directly connected to it is on a body of water with nothing in between the two radios ( the water acts as an improved ground plane, topic for another time). Dammit where did those paragraphs run off to???
Last edited by dragon5126; 10-08-2011 at 03:12 AM. Reason: found the pair of graphs
Very good discussion on antenna's. It is hard to describe, understandably, how they work. You did good.
Next you get to describe the various types of antenna's.
heck thats easy! first there are antennas that stick up in the air, then there are antennas that lay side ways and then there are broken antennas... any questions? Seriously though... It'll have to wait til I have two eyes... got an infection in my right eye and am fighting the eyestrain which is why I've been absent as of late. but if everyone will come up with questions it will speed up the explanations, and the theory applies to all radio communications not just gmrs.
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