Good morning all, I hope that everyone had a good Thanksgiving.
Now, in light of the overwhelming knowledge base and expertise located in this forum, I was hoping to find answers and possibly help in deciding which antenna to build for best performance in my application
I live in a flat, urban area 6 miles from the coast in VA beach. I am married and have two kids, so I am not the only one living in the house nor am I the only one who uses the backyard. I am not in a home owners association, so I am not limited by HOA restrictions, but I am married, and the wife does not want a big antenna on the roof and does not want whatever I decide to go with taking up too much backyard space (where the kids play)
So far this is what I have come up with. Option 1 is a ground mounted 1/4 wave vertical with 32 radials pinned to the ground (which should be out of the way of mowing the yard, the kids playing, etc...) I have built one of these before to see how well it would work and was surprised. I used a 102" SS whip as the radiator and the radials were 108" 16awg stranded wire. The old base plate was about 4" diameter aluminum sheet (round conduit j-box cover) and the radials were attached with ring connectors and screws. The antenna seemed to perform well, but I did not like this base plate set-up after the fact as I thought it could be improved.
My issue with this antenna is it's location with respect to the house. My house is rectangular with the front facing west and the back facing east. The ocean front is approx. 6 miles from my back door. I would like to be able to communicate mobile to base more westward than eastward, as I am sometimes between my house and the beach but am more due west because of work. The first problem with this antenna at ground level in the back yard is that there is a building (my house) between it and the direction that I would be mostly trying to communicate with. My first question is how much does a typical 1 story house attenuate an RF signal? My second problem is actual distance from the vertical to the house. I have two options here: 18' with a modified radial layout because of obstructions (fire pit patio) or 9' with a completely symmetrical radial layout. I guess my question here is: I know that anything within the antennas near field is going to have a major effect, but exactly how far does it extend? If I mounted the antenna somewhere between the two, like say 14.5', would this be a good compromise in the radial layout AND get the house out of the near field? These are my concerns with this antenna.
My second option is a shortened, elevated 1/4 wave GP, made of mobile fiberglass whips. Elevation can't be too high though, figure about 13' off of the ground, attached to a roof mounted Directv dish mount. I have never actually built this antenna, but understand the concept and think it will work. I could probably go with a 5-6 ft vertical and use four 3-4 ft radials, or maybe totally symmetrical with vertical and radials the same length. I know I will have to play around with the radial angles to get a good impedance match to 50 ohms, and lengths to make it resonant, but think I can manage it. I know that with a full size 1/4 wave GP, optimum radial angle is 45 degrees for a 50 ohm impedance match, and with a fiberglass antenna being lower in impedance than a 1/4 wave whip, I should need about 60 degrees downward slope to achieve a 50 ohm impedance, but I could be wrong. I will need to do some testing before I can speak confidently about that angle. This antenna would be in the clear with regards to obstructions, and would not take up back yard space or be too noticeable (especially in black and against the trees in the back ground) Plus, mobile whips are cheap and I like building antennas.
So, I guess my biggest question here is: which of these two antennas would perform the best in my application and is there another option that I have not thought of yet? And beams, an A99, or an IMAX is simply out of the question. Thank you in advance for your responses.
Now, in light of the overwhelming knowledge base and expertise located in this forum, I was hoping to find answers and possibly help in deciding which antenna to build for best performance in my application
I live in a flat, urban area 6 miles from the coast in VA beach. I am married and have two kids, so I am not the only one living in the house nor am I the only one who uses the backyard. I am not in a home owners association, so I am not limited by HOA restrictions, but I am married, and the wife does not want a big antenna on the roof and does not want whatever I decide to go with taking up too much backyard space (where the kids play)
So far this is what I have come up with. Option 1 is a ground mounted 1/4 wave vertical with 32 radials pinned to the ground (which should be out of the way of mowing the yard, the kids playing, etc...) I have built one of these before to see how well it would work and was surprised. I used a 102" SS whip as the radiator and the radials were 108" 16awg stranded wire. The old base plate was about 4" diameter aluminum sheet (round conduit j-box cover) and the radials were attached with ring connectors and screws. The antenna seemed to perform well, but I did not like this base plate set-up after the fact as I thought it could be improved.
My issue with this antenna is it's location with respect to the house. My house is rectangular with the front facing west and the back facing east. The ocean front is approx. 6 miles from my back door. I would like to be able to communicate mobile to base more westward than eastward, as I am sometimes between my house and the beach but am more due west because of work. The first problem with this antenna at ground level in the back yard is that there is a building (my house) between it and the direction that I would be mostly trying to communicate with. My first question is how much does a typical 1 story house attenuate an RF signal? My second problem is actual distance from the vertical to the house. I have two options here: 18' with a modified radial layout because of obstructions (fire pit patio) or 9' with a completely symmetrical radial layout. I guess my question here is: I know that anything within the antennas near field is going to have a major effect, but exactly how far does it extend? If I mounted the antenna somewhere between the two, like say 14.5', would this be a good compromise in the radial layout AND get the house out of the near field? These are my concerns with this antenna.
My second option is a shortened, elevated 1/4 wave GP, made of mobile fiberglass whips. Elevation can't be too high though, figure about 13' off of the ground, attached to a roof mounted Directv dish mount. I have never actually built this antenna, but understand the concept and think it will work. I could probably go with a 5-6 ft vertical and use four 3-4 ft radials, or maybe totally symmetrical with vertical and radials the same length. I know I will have to play around with the radial angles to get a good impedance match to 50 ohms, and lengths to make it resonant, but think I can manage it. I know that with a full size 1/4 wave GP, optimum radial angle is 45 degrees for a 50 ohm impedance match, and with a fiberglass antenna being lower in impedance than a 1/4 wave whip, I should need about 60 degrees downward slope to achieve a 50 ohm impedance, but I could be wrong. I will need to do some testing before I can speak confidently about that angle. This antenna would be in the clear with regards to obstructions, and would not take up back yard space or be too noticeable (especially in black and against the trees in the back ground) Plus, mobile whips are cheap and I like building antennas.
So, I guess my biggest question here is: which of these two antennas would perform the best in my application and is there another option that I have not thought of yet? And beams, an A99, or an IMAX is simply out of the question. Thank you in advance for your responses.
