Is one better than the other between 1/4 and 1/2
All my RX path questions
- Thread starter Bonkk083
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If your talking a single 1/4 wave vs a single 1/2 wave, the 1/2 wave will have slightly more gain at the horizon. The 57" and 65" long antennas you mention would be stacked colinear types and the fractional wavelength of each element is no longer relevant and its the overall design that makes one better than the other. Generally bigger is better and if the shorter one claims more gain I would be suspicious.
I just doubled checked I had it backwards the 1/4 is 65" @ 6 dbd and the 1/2 is 57" @ 4
The bigger one should be better and it doesn't matter if its got 1/4 wave or 1/2 wave elements, although I've never heard of a stacked colinear using all 1/4 wave elements.
It's 806-866 and center frequency is 813 whatever that means
Pointed the same direction for increased gain and narrower beam width I hope?
Different directions
You will loose 3dB or half your signal strength in doing this. If you take two identical 10dBd Yagis and point them different directions then use a coax phasing harness, 2-way divider or 3dB hybrid coupler that will loose 3dB of signal from both antennas making them the equivalent of 7dBd gain Yagis. In this case it would be better to use a 10dBd omni unless you need to null out a signal from a particular direction.
I haven't found a 10 dbd omni
Childs has a 9dBd (11.1dBi) omni for $199 new. There used to be lots of them used cheap like $75 at ham swap meets.
If I just wanted to point it in one direction would go with a yagi with 13-14 dbi, Are they much difference between 11 dbi and 13-14 dbi.
2 or 3dB will make a slight difference on a weak signal. A little less noise.
I talked to someone at a antenna place they said that I needed 12-15 dbi for the 36-45 mile distance, If it's not much of a difference I might go with the Omni I might could possibly get both
If I told you to put 120psi in your tires it would save you 3mpg in gas would you believe me? Treat that antenna place the same way with nonsense information like that.
I wouldn't believe it, I wasn't doubting your word, I get all kind of suggestions
Ubbe
Member
What frequencies do you want to receive? I took a look at Bruce Childs antennas and he specifies that they have a 4% bandwidth, that's usually when they are 3dB down. One antenna looks like this:
Base 8009 800-850 Mhz, 9 dbd, N female
4% at 800MHz are 30MHz.
Antenna gain needed can be very local even at 150MHz. If I move my VHF antenna 3-4 meters, 10ft, the signal change dramatically while I move it, but then I do not have line of sight to the transmit antenna that will make it sensitive to where I locate the receive antenna. Some sites will be better and others worse depending of their directions and where I have my antenna. Sometimes one of my UHF antennas will receive a VHF signal better than the VHF antenna due to its better position for that specific site.
/Ubbe
Base 8009 800-850 Mhz, 9 dbd, N female
4% at 800MHz are 30MHz.
Antenna gain needed can be very local even at 150MHz. If I move my VHF antenna 3-4 meters, 10ft, the signal change dramatically while I move it, but then I do not have line of sight to the transmit antenna that will make it sensitive to where I locate the receive antenna. Some sites will be better and others worse depending of their directions and where I have my antenna. Sometimes one of my UHF antennas will receive a VHF signal better than the VHF antenna due to its better position for that specific site.
/Ubbe
851-860
Antenna frequency range has little to do with gain, the band edges are usually specified with a maximum VSWR like 1.5:1. However antenna beam width will be specified at the 3dB down points like a 10dBd gain omni will have around 7 degrees (+/- 3.5 degrees) of beam width at the -3dB down points compared to the horizon, assuming no downtilt.
The 14 dbi yagi VSWR is 1:5:1 also should I be looking at the VSWR
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