I like having an onmi on vhf but am having trouble picking up some 800 towers. Is there some info about maybe using more than one antenna on the same wire? Has anyone done this with success? Is phasing an issue?
A cable TV splitter can be used as a combiner if you connect it "backwards"--individual antennas to the outputs and the main antenna coax to the input. Good ones will give you 20dB or more of isolation.
I don't want to transmit just receive so I don't need a duplexer. I am just wondering about receiving pattern of the combined antennas. If I get a high gain 800 yagi and parallel a vhf onmi with it will it affect the gain of the yagi?
Again, 75 ohm equipment makes it easyI like having an onmi on vhf but am having trouble picking up some 800 towers. Is there some info about maybe using more than one antenna on the same wire? Has anyone done this with success? Is phasing an issue?
Again, 75 ohm equipment makes it easy
Buy a RCA vhf/UHF tv preamp for 25 bucks
It has separate vhf and uhf inputs so it can easily combine a vhf omni and a 800mhz antenna and will eliminate all feedline loss so it will outperform any passive device like splitters, combiners, and diplexers
Although prcguy mentioned two antennas with a properly phased harness, and some opportunity for gain, what nobody has mentioned is what happens when you don't take the phase, or time of arrival into account. When two antennas, separated by some unknown multiple of wavelengths, receive the same signal, at roughly the same time, but slightly out of phase, you can actually cancel out the intended signal on your coax. Many of you have already experienced this with a single antenna mobile installation, with what many call "picket fencing". This is caused by the signal having more than one path to your antenna, and the signals from those multiple paths arriving slightly (or maybe 180 degrees) out of phase, and causing cancellation or nulling. The same thing can occur with two antennas feeding the same feedline. I'm not sure what the results of an omni antenna and a directional yagi would be, but you're better off with maybe separate antennas and feedlines, and using a coaxial switch to select the one you want connected to your receiver.
This subject comes up from time to time, and many people gave some good inputs here: http://forums.radioreference.com/sp...57-running-one-scanner-multiple-antennas.html