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Wolverine
Intermediate Member
Username: Wolverine

Post Number: 294
Registered: 2-2003
Posted on Thursday, January 13, 2005 - 3:58 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I live on the 3rd floor of an apartment complex. I have a metal table that is 3 ft square. I have my Anttron A-1700 mobile antenna, mounted to the table, via truck mount. Since I can't install an outdoor antenna, this set-up kicks butt. I can get out 15 to 20 miles on any given day. I know that co-phased antennas on big rig trucks require a special wiring harness or coax to couple the antennas, and that the antennas need to be 9ft apart. Question: If I were to mount a 2nd antenna on my metal table, 3 ft in front of the other antenna (Length of table), could I achieve some type of directed beam effect, or a narrowing of my signal, no matter how nominal the gain??. Is this a worthwhile project, or just a waste of time and energy?. I would be happy with any significant beaming effect, no matter how small, Can this work? Will it work? Your answers are appreciated. Thanks in advance.
Wolverine.
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Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 140
Registered: 9-2004
Posted on Thursday, January 13, 2005 - 5:13 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

i dont think any project like this is a waste of time. you should do it just to see the difference. unfortunately, co phased antennas are 102" apart so that they will work "with" eachother. any closer than that and they just work against eachother.
the good news is; your table is already directional, sort of. if the antenna is mounted to the edge of the table, then your antenna is directional toward the opposite end of the table.
so point the table out the window or out th back door.
good luck.
matt
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Wolverine
Intermediate Member
Username: Wolverine

Post Number: 295
Registered: 2-2003
Posted on Friday, January 14, 2005 - 2:52 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Work against each other? Interesting. Maybe it's because since the antennas are so close, the Rf coming from both ants will cancel each others radiation pattern. Could this effect my already perfect 1.2 SWR ?, maybe. Maybe I should find a 9ft metal table for experimentation purposes. Rats. Another good theory bites the dust.
Wolverine.
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Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 143
Registered: 9-2004
Posted on Saturday, January 15, 2005 - 8:16 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

we're not licked yet!

how about this. go to the home depot and get a ten foot length of conduit or copper plumbing pipe. whatever diameter will work for you. cut the pipe to 102" and clamp it corner to corner, centered on the table. making sure you have good metal to metal connection. then mount one antenna at either end of the pipe. i dont remember how to make a cophase harness off hand but i'll look it up and post it here. if you've got the room inside to turn this thing, it should be pretty cool.
matt
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Allagator
Advanced Member
Username: Allagator

Post Number: 542
Registered: 9-2002


Posted on Monday, January 17, 2005 - 8:52 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

now it mite be alot easier to build a dipole and fix it so you can move it real easy !!! or if you can have a flag pole make a dipole and use some tape and pvc pipe to make a pole with and tape the wire to the side of the pipe and that will work ok !! but watch for TVI with a wire antenna !!
Just a idea !!!
Allagator !!
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Wolverine
Intermediate Member
Username: Wolverine

Post Number: 296
Registered: 2-2003
Posted on Tuesday, January 18, 2005 - 2:16 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Kid vicious, that's an excellent idea. Unfortunately I don't have the room to spare, but I do understand the concept. The pipe would act like a "Boom", where I can attach the antennas at opposite ends (Novel idea), then I would attach a co phasing harness to bring both antennas to resonance/swr, etc. Kid, in order to do as you suggested, I would have to remove the table's glass top, so I could get the metal to metal, or table to boom contact. Then I would have rendered a table totally useless, where you couldn't put anything on top of it, then my girlfriend would go into the closet to retrieve "Ole Betsy", and commence to blast me into the next dimension. I then, would have truly died, for my hobby. All jokes aside Kid vicious, thanks for that great idea. It's impractical for me to make the mods now, but I know what to do in the future, if given the chance. EXCELLENT IDEA!!
Wolverine.
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Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 147
Registered: 9-2004
Posted on Tuesday, January 18, 2005 - 9:13 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

oh, you didnt mention the girlfriend factor! when you live alone it doesnt matter if your apartment looks like an antenna test range. you'd best keep the peace so you dont end up sitting in the mobile trying to talk skip.
all kidding aside i find that a quarter wave dipole works best for an indoor antenna.
matt
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Wolverine
Intermediate Member
Username: Wolverine

Post Number: 300
Registered: 2-2003
Posted on Wednesday, January 19, 2005 - 2:20 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Point Taken.

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