I am wondering what the difference is between three different antenna systems is. I was going to try and draw pictures of them but it ended up looking like a 6 year old drew it after having too much sugar lol. So I will try to explain them instead.
First system would be your basic multi band antenna, sort of like the large tv antenna's you see, but made for radio waves. A yagi antenna for UHF (800mhz) and then a bunch of different length elements to cover the lower frequencies. Basically an antenna that would cover 100-400 and 800mhz. All the elements on the same boom with a 300 ohm twin lead connected to a 75 ohm matching transformer.
The next system would be a Dipole antenna, or maybe a long periodic for VHF and then a directional high gain UHF yagi mounted above it on the same mast. Then connect the yagi to the dipole with 300 ohm twin lead. And then connect the dipole to a 75 ohm matching transformer and running coax to the scanner. Is there any reason why the two antennas wouldn't "think" they were on the same boom?
The third would be the same yagi/dipole combination, but instead of connecting them with 300 ohm twin lead each would have its own matching transformer with 75 ohm coax running into a splitter then running one coax lead to the scanner.
I understand from reading other posts that the third option is a bad idea, basically running two separate antennas to one scanner. What I don't know is WHY this is bad. Does it change the load the scanner sees, does it lower the signal too much, or do they cancel each other out or something?
And what would the difference between system one and system two be? To me it seems like they are the same thing, just not on the same boom is all. Is there some reason system two wouldn't work, but system one does?
System two would be ideal for me (if it works) because I could use the dipole as a non directional 150mhz antenna, which I am using now and it works great. Then the high gain yagi could be used as a high gain, directional 800mhz antenna that I could aim at different trunked site towers. My complete lack of knowledge of antennas is telling me this could probably work. But in the back of mind something is telling me it won't work because of some technical reason I don't understand. Because if it worked, I would see others doing it, and I haven't.
Something is telling me system one is a compromise, but would work and systems 2 and 3 are a horrible idea and won't yield me anything but a waste of metal, money and time. And that the only real good approach is to have multiple scanners each with dedicated antennas tuned for a specific range. Which equates to expensive, and having antennas all over my house lol.
Any input would be appreciated, thanks. Honestly I am just bored and kicking ideas around in my head.
First system would be your basic multi band antenna, sort of like the large tv antenna's you see, but made for radio waves. A yagi antenna for UHF (800mhz) and then a bunch of different length elements to cover the lower frequencies. Basically an antenna that would cover 100-400 and 800mhz. All the elements on the same boom with a 300 ohm twin lead connected to a 75 ohm matching transformer.
The next system would be a Dipole antenna, or maybe a long periodic for VHF and then a directional high gain UHF yagi mounted above it on the same mast. Then connect the yagi to the dipole with 300 ohm twin lead. And then connect the dipole to a 75 ohm matching transformer and running coax to the scanner. Is there any reason why the two antennas wouldn't "think" they were on the same boom?
The third would be the same yagi/dipole combination, but instead of connecting them with 300 ohm twin lead each would have its own matching transformer with 75 ohm coax running into a splitter then running one coax lead to the scanner.
I understand from reading other posts that the third option is a bad idea, basically running two separate antennas to one scanner. What I don't know is WHY this is bad. Does it change the load the scanner sees, does it lower the signal too much, or do they cancel each other out or something?
And what would the difference between system one and system two be? To me it seems like they are the same thing, just not on the same boom is all. Is there some reason system two wouldn't work, but system one does?
System two would be ideal for me (if it works) because I could use the dipole as a non directional 150mhz antenna, which I am using now and it works great. Then the high gain yagi could be used as a high gain, directional 800mhz antenna that I could aim at different trunked site towers. My complete lack of knowledge of antennas is telling me this could probably work. But in the back of mind something is telling me it won't work because of some technical reason I don't understand. Because if it worked, I would see others doing it, and I haven't.
Something is telling me system one is a compromise, but would work and systems 2 and 3 are a horrible idea and won't yield me anything but a waste of metal, money and time. And that the only real good approach is to have multiple scanners each with dedicated antennas tuned for a specific range. Which equates to expensive, and having antennas all over my house lol.
Any input would be appreciated, thanks. Honestly I am just bored and kicking ideas around in my head.