Best Antenna
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- stylzmovement
- Compulsive poster:)
- Posts: 142
- Joined: Sat Oct 11, 2003 8:59 pm
Best Antenna
What antenna do you use ?
do you like your coverage?
are there any problems with the antenna ?
will you like to change the antenna to another ?
for what reason?
do you like your coverage?
are there any problems with the antenna ?
will you like to change the antenna to another ?
for what reason?
- stylzmovement
- Compulsive poster:)
- Posts: 142
- Joined: Sat Oct 11, 2003 8:59 pm
Re: Best Antenna
From our website:stylzmovement wrote:What antenna do you use ?
do you like your coverage?
are there any problems with the antenna ?
will you like to change the antenna to another ?
for what reason?
1.) The best omnidirectional single antenna right now is 3/4 wave.
2.) If you have a bit more money, 4 dipoles in multi-bay really kick ass.
If cost is an issue, comet really performs nicely and is also nicely build.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
- stylzmovement
- Compulsive poster:)
- Posts: 142
- Joined: Sat Oct 11, 2003 8:59 pm
I'm using a DIY "slim-jim" constructed pretty much in keeping with these plans from a PCS site link. I rescaled it for 104.1 MHz, it's resonant at 103.8 MHz, and I'm running 7W from a MaxPro I into it at a couple MHz less than that with a VSWR of 1.05:1. I modified the design a bit by using a cross-drilled hole at the lower end (rather than a notch) to allow for a bit of a stub-end of PVC on the inner pipe, and used nylon push-pins to secure the wire ends (18 ga. solid copper) at the gap.
It's only about 20 ft above ground (very flat ground here), fed with 50 ft. of RG-8. I'm delivering rock solid stereo reception out to 1-1/4 miles, a bit noisy but soild to 2 miles and as much as 3+ miles if the wind is right...
It's only about 20 ft above ground (very flat ground here), fed with 50 ft. of RG-8. I'm delivering rock solid stereo reception out to 1-1/4 miles, a bit noisy but soild to 2 miles and as much as 3+ miles if the wind is right...
-cliff knight-
My Miata
My Miata
Me again,
You may want to check out this series of articles describing modeling of j-poles and "slim-jims"--the author's conclusion is that nearly any j-pole based design will deliver 5+ dB gain at 6° above the horizon. This is 1.0 to 1.5 dB better than a 5/8 λ ground plane, and probably 2 dB better then a 1/4 λ GP.
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You may want to check out this series of articles describing modeling of j-poles and "slim-jims"--the author's conclusion is that nearly any j-pole based design will deliver 5+ dB gain at 6° above the horizon. This is 1.0 to 1.5 dB better than a 5/8 λ ground plane, and probably 2 dB better then a 1/4 λ GP.
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-cliff knight-
My Miata
My Miata
OK, one more then I'm done...
The same fellow that wrote the j-pole modeling series performed this exercise modeling 2-meter ground planes at 1/4 λ and 5/8 λ--the results are interesting and although pefromed for the 2 meter ("146 MHz") band they remain relevant at 3 meters.
The bottom line is that for high mounted antennas the 5/8 λ has very little practical advantage over the 1/4 λ model because the longer vertical element's advantage is almost entirely at the higher radiation angles.
This is all fresh in my mind because I just completed a week's research into finding a higher performance alternative to my homebrew slim-jim, which intuitively can't be the "best antenna" (I mean heck, I made it myself for less than $10)--however, it turns out it probably is the best, unless you want to setup and tune an array, or use a directional rig to beam the signal...
The same fellow that wrote the j-pole modeling series performed this exercise modeling 2-meter ground planes at 1/4 λ and 5/8 λ--the results are interesting and although pefromed for the 2 meter ("146 MHz") band they remain relevant at 3 meters.
The bottom line is that for high mounted antennas the 5/8 λ has very little practical advantage over the 1/4 λ model because the longer vertical element's advantage is almost entirely at the higher radiation angles.
This is all fresh in my mind because I just completed a week's research into finding a higher performance alternative to my homebrew slim-jim, which intuitively can't be the "best antenna" (I mean heck, I made it myself for less than $10)--however, it turns out it probably is the best, unless you want to setup and tune an array, or use a directional rig to beam the signal...
-cliff knight-
My Miata
My Miata
I find one other advantage using a slim jim over a comet. The slim jim I built can be on a thin pole set higher than a comet, from the same tower as a starting point. There is less wind resistance IMO. With solid 30 feet of 3 legged tower, one can push up almost another 30 feet of one inch steel mast tubing (about 20 feet above the tower) with a desert slim-jim on top of that. If the wind is real high, or you want to go higher still, you can use guy wires ten feet below the base of the desert slim jim. Elevation is key. In an equal height antenna test, i find the slim jim to work slightly better than a comet.cliffyk wrote:OK, one more then I'm done...
[snip] at 1/4 λ and 5/8 λ--the results are interesting and although pefromed for the 2 meter ("146 MHz") band they remain relevant at 3 meters.
The bottom line is that for high mounted antennas the 5/8 λ has very little practical advantage over the 1/4 λ model because the longer vertical element's advantage is almost entirely at the higher radiation angles.
...