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Antenna Questions, novice
I'm trying to sort through some material I have read regarding setting up an antenna for general shortwave reception, probably in the 4,000 - 12,000 MHz range(??), for a modest SW receiver (table top model with AF gain, RF gain, band spread, S-meter, BFO Pitch adjustment, antenna trim, etc.). From the materials I have read, I can get reasonably good general SW reception (though not great reception of code or Ham broadcasts), with an antenna of around 30 - 100 feet. As understood, the antenna wire could be simply routed around the room; or, put in the attic; or, alternatively, strung outside, suitably in an "inverted L" configuration. (I'm not going to get into directionaly antenna arrays for Ham reception at the present time.) If I string a straight length of antenna wire outside (which would probably be longer than the wavelengths of most signals I'll be listening to), is its reception directional, and if so, should it preferably be "aimed" in a certain direction? (Assuming that I would probably want to listen most often to stations that are located east northeast of our location here in Texas?) I'm guessing that it should be perpendicular to the direction from which most signals would come from. Also, is there a significant advantage to running it at an angle rather than horizontally, as in some designs? Thanks for any suggestions. Jim |
Antenna Questions, novice
JimC wrote: I'm trying to sort through some material I have read regarding setting up an antenna for general shortwave reception, probably in the 4,000 - 12,000 MHz range(??), for a modest SW receiver (table top model with AF gain, RF gain, band spread, S-meter, BFO Pitch adjustment, antenna trim, etc.). From the materials I have read, I can get reasonably good general SW reception (though not great reception of code or Ham broadcasts), with an antenna of around 30 - 100 feet. As understood, the antenna wire could be simply routed around the room; or, put in the attic; or, alternatively, strung outside, suitably in an "inverted L" configuration. (I'm not going to get into directionaly antenna arrays for Ham reception at the present time.) If I string a straight length of antenna wire outside (which would probably be longer than the wavelengths of most signals I'll be listening to), is its reception directional, and if so, should it preferably be "aimed" in a certain direction? (Assuming that I would probably want to listen most often to stations that are located east northeast of our location here in Texas?) I'm guessing that it should be perpendicular to the direction from which most signals would come from. Also, is there a significant advantage to running it at an angle rather than horizontally, as in some designs? Thanks for any suggestions. Jim As a novice that just put up an antenna for listening maybe the following will help. I intially put up a windom antenna in the attic and had much RFI from inside the house. I did a lot of reading and asked many questions here and ended up with the following. I ended up installing an "inverted L" antenna. It is about 85 feet long horizontal and 15 - 20 feet high as it covers the backyard. I installed a hook at the peak of the house roof and a heavy spring off an aluminum screen door. Attached to this I have about 45 feet of nylon rope between it and the insulator at the start of the antenna wire. This gets the wire at least 15 feet away from anypart of the house to reduce RFI. From here the antenna wire, (#14 gauge insulated stranded wire from Home Depot) goes 85 feet to an insulator that is attached to a short lenght of nylon rope attached to a mast on an outbuilding. The wire then goes down about 15 feet to a 10:1 balun which is mounted directly to a ground rod sticking about 15" above the ground. From the balun I buried 135 feet of RG-6 outdoor coax about 5" under the grass and ends at a ground block at the house. The ground block is also connected to another ground rod installed nearby. From the ground block I have 50 feet of RG-6 coax that goes into the house and terminates at a TV type matching transformer with the guts taken out so I can attach to my recievers screw terminals. The interferance that I got with the attic antenna is not there and this antenna is quiet and I recieve many more stations. I am happy with this setup and since I used white nylon rope, antenna wire, and insulators it is not an eye sore. Hope this helps. Brian |
Antenna Questions, novice
"JimC" wrote in message ... Thanks for the information. - I had hoped to be able to get by with a less complicated system. For example, it would be difficult for me to bury 135 feet of coax in our backyard and connect through a suitable balun and matching transformer. Obviously, I need to do some further research. Re my other question, does anyone have any thoughts about whether the horizontal antenna wire should be oriented to enhance reception in the direction in which most signals will arrive? (Recognizing that they are bouncing around, and that some will come from other directions.) Jim Regarding orientation, your assumption is correct. A wire, up to a certain length, oriented perpendicular to the desired signal direction will perform best for those signals. -Brian |
Antenna Questions, novice
JimC wrote: Thanks for the information. - I had hoped to be able to get by with a less complicated system. For example, it would be difficult for me to bury 135 feet of coax in our backyard and connect through a suitable balun and matching transformer. Obviously, I need to do some further research. Re my other question, does anyone have any thoughts about whether the horizontal antenna wire should be oriented to enhance reception in the direction in which most signals will arrive? (Recognizing that they are bouncing around, and that some will come from other directions.) Jim Do a google search in this newsgroup for "INVERTED L" DIRECTIONAL and you will see the lengths needed to make an "inverted L" omni-directional. Brian |
Antenna Questions, novice
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Antenna Questions, novice
Run a wire in any direction you wish. It won't be directional enough
to matter. Just get it as high as you conveniently can. And it will pick up ham signals just fine if it's in the general range of 30' to 100' feet, as you indicated. Hams make their antennas in certain exact lengths because of transmitting requirements, but for simply receiving signals, length doesn't matter that much. Have fun... bob k5qwg On Thu, 18 Jan 2007 04:26:08 GMT, JimC wrote: I'm trying to sort through some material I have read regarding setting up an antenna for general shortwave reception, probably in the 4,000 - 12,000 MHz range(??), for a modest SW receiver (table top model with AF gain, RF gain, band spread, S-meter, BFO Pitch adjustment, antenna trim, etc.). From the materials I have read, I can get reasonably good general SW reception (though not great reception of code or Ham broadcasts), with an antenna of around 30 - 100 feet. As understood, the antenna wire could be simply routed around the room; or, put in the attic; or, alternatively, strung outside, suitably in an "inverted L" configuration. (I'm not going to get into directionaly antenna arrays for Ham reception at the present time.) If I string a straight length of antenna wire outside (which would probably be longer than the wavelengths of most signals I'll be listening to), is its reception directional, and if so, should it preferably be "aimed" in a certain direction? (Assuming that I would probably want to listen most often to stations that are located east northeast of our location here in Texas?) I'm guessing that it should be perpendicular to the direction from which most signals would come from. Also, is there a significant advantage to running it at an angle rather than horizontally, as in some designs? Thanks for any suggestions. Jim |
Antenna Questions, novice
Bob Miller wrote: Run a wire in any direction you wish. It won't be directional enough to matter. Just get it as high as you conveniently can. And it will pick up ham signals just fine if it's in the general range of 30' to 100' feet, as you indicated. Hams make their antennas in certain exact lengths because of transmitting requirements, but for simply receiving signals, length doesn't matter that much. Have fun... bob k5qwg Thanks for the information. - I'll try to get it as high as possible. Does it matter significantly whether the wire extends horizontally, vertically, or diagonally? Jim |
Antenna Questions, novice
On Thu, 18 Jan 2007 16:13:02 -0600, JimC
wrote: Bob Miller wrote: Run a wire in any direction you wish. It won't be directional enough to matter. Just get it as high as you conveniently can. And it will pick up ham signals just fine if it's in the general range of 30' to 100' feet, as you indicated. Hams make their antennas in certain exact lengths because of transmitting requirements, but for simply receiving signals, length doesn't matter that much. Have fun... bob k5qwg Thanks for the information. - I'll try to get it as high as possible. Does it matter significantly whether the wire extends horizontally, vertically, or diagonally? Jim Vertical wires can pick up more man made noise. Horizontal or diagonal may be a tad quieter. bob k5qwg |
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