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SKYY WAVE ANTENNA

Y

youngest man

Member
Nov 1, 2005
31
0
16
11 METER BEAM ANTENNAS (27.025) SKYY WAVE ANTENNAS ARE FAR DIFFERENT THAN ANY OTHER BEAM WE DO USE THE SAME TYPE ANTENNA STYLE LIKE MACO BEAMS BECAUSE WE USE THERE PARTS BUT OUR BEAMS ARE SET UP DIFFERENT THE SPACING IS DIFFERENT AND THE LENGTH OF THE ELEMENTS ARE DIFFERENT I BUILT TO PROTO TYPES AND HAD GOOD SUCCESS WITH BOTH ANTENNA I BUILT A 3ELEMENT BEAM IT 13FT 9" LONG AND I BUILT THE BEAM TO DBI SPEC. THE DBI ON THIS BEAM IS 8.19DBI AND THE FRONT TO BACK RATIO IS 82.77DB GAIN AND IT CAN OUT TALK ANY 4 ELEMENT OR 5 ELEMENT BEAM AND YOU CAN HERE ALOT ON IT. THE SKYYWAVE 3 EVERYTHING COMES OUT THE FRONT OF THE BEAM. THE BACK END OF THIS BEAM IS REAL TIGHT. I JUST BUILT A 7 ELEMENT BEAM 28.50FT AND THE DBI IS 10.51 DBI AND THE FRONT TO BACK RATIO IS 86.52 DB GAIN. THIS BEAM IS WELL MADE AND WE TUNED IT TO 27.025 FREQ. WITH A 1.1 SWR WITH 500 BIRD WATTS AND IT MAKE YOU SOUND LIKE YOU ARE RUNNING BIG WATTS.

THIS EXPLAINS WHAT DBI IS.



decibels relative to isotropic radiator

The expression dBi is used to define the gain of an antenna system relative to an isotropic radiator at radio frequencies. The symbol is an abbreviation for "decibels relative to isotropic."

The dBi specification is based on the decibel, a logarithmic measure of relative power. Suppose an antenna A produces an electromagnetic field of intensity IA microwatts per square meter (IAµW/m2) in its favored direction at a point located some distance away. Also, suppose an isotropic antenna Q produces an electromagnetic field of intensity IQ µW/m2 at the same distance. Then the gain G of antenna A, in dBi, is:

G = 10 log10 (IA / IQ)

http://whatis.techtarget.com/definition/0,,sid9_gci214571,00.html
 

1: You don't "build" a beam to "DBI" spec, you MEASURE it against it.

2: A 3-element beam will never have 8+ dbi gain.
(UPDATE: Force 12 lists their 3-element 10 meter beam at 13.4 dbi. But this is how they get to this number, "For horizontal antennas, dBi is the computed gain of the antenna at typical height of 74’ (-over average, real ground-), compared to the theoretical isotropic source (reference). This dBi figure will be familiar to those who do computer modeling and is numerically much larger (7-7.5dB) than the “apples to apples” dBd figure. This difference comes from two places. One is from the difference between the theoretical isotropic source in free space to a dipole in free space, which accounts for 2.14dB (see the demo above). The second is from “ground reflection gain,” which is the enhancement for a horizontal antenna, due to the effect of the ground. This applies only to horizontal antennas and its height above real ground. The average ground reflection gain will be 4.5-5.8dB. If the 2.14 (from the isotropic source) and 5.9 (maximum ground reflection gain) are subtracted from the dBi figure, one will arrive at approximately the dBd “apples to apples” number."

3: 87+ db front to back?! Really?! How did you come up with that?

4: What is your point? Is your post your attempt to market these antennas to the forum members? If so, and I don't have a problem with it, you should post the information where they can go to buy this antenna.

4: Would you like me to spell check your post for you?
 
youngest man ,
what do you use for a The gamma match?
what is the total boom length?

youngest man ,wrote..
I BUILT A 3ELEMENT BEAM IT 13FT 9" LONG

now the frequency that you posted 27.025 (11 meter channel 6)
calls for a Reflector Length (longest element) of 18ft. 6 - 15/32in. or 5.651 M

you have it for 13FT 9" long, judging your talking about the Reflector..

And why you you adjust the frequency of the (beam)antenna to channel 6...and not channel 20 for a smoother,more centered band spread?
 
As another guess, I'd think that 13.75 feet thingy might be the boom length. Only thing I can think of that would be close to that figure.
I honestly can't think of any way to get a F/B of something like 80 dBi. A large F/B usually results from a lowered frontal gain. High gain, low F/B, and visa versa.
I'm afraid I have to say that the '8.? dBi' gain is just playing with numbers. Converting to dBd would mean something like 6 dB of gain, which is reasonable for a three element yagi.
Except for the F/B I'd have to think it's a fairly typical three element beam. Is it better than others? Beats me. Bound to be better than some, and then again, worse than others.
One fairly 'simple' way to test a beam is to pick the thing up and shake the fire out of it! If it stays together and doesn't sort of bend, it's probably a decent antenna. You don't see that 'test' in may antenna books. But it's a pretty good one. Think about it...
- 'Doc
 
13.9ft boom is a big spread for the 3 elements

I mean this spitfire 427 3 element beam has a boom length of 8 foot and calls for a Reflector Length (longest element) of 18ft. 6 - and thats tuned for 11 meters(channel 20)
and has a nice bandwidth channels 1-80 and a 1.2.1 SWR rating..
hope he did his homework on this before selling even 4 of them to find out there just weight for the rotors :p

personally, I think hes talking smack :LOL:
I'd like to hear more from him on this not so home brew antenna

11 METER BEAM ANTENNAS (27.025) SKYY WAVE ANTENNAS ARE FAR DIFFERENT THAN ANY OTHER BEAM WE DO USE THE SAME TYPE ANTENNA STYLE LIKE MACO BEAMS BECAUSE WE USE THERE PARTS

so what your saying you put their beam on a longer boom and space it differently??? And what do you have for backing up the, "it works great" theory?
 
i see nothing special here
his 8 Dbi eqates to 6 odd Dbd as DOC said

boom length is fine

longer elements (what is their length ? )

wider spaced elements
only advantage there is likly lower swr over greater mhz
(more broad banded perhaps)

how he could get remotly close to 80 Dbi F/B
i do not see how that could be
one way to inprove F/B is more elements
but that would make it very narrow banded
(which would require more elements)
and i still do not think such a high F/B is capable
 
off the top of my head
i can think of 2 beams that would traunce his homebru/prodotype

jay's Crusaders

and

SteppIr beams

although both have longer boom
(and that is where gain is mostly from)

and neither come close to the F/B figures he is claiming
and both these antennas are considered very good F/B
 
I'M NOT ON HERE TO TRY TO SELL THIS ANTENNA I'M ON HERE TO SEE WHAT YOU ALL THINK ABOUT THIS I TALK ON THE 3 ELEMENT ANTENNA THE BOOM IS 13FT 9IN YES YOU ARE RIGHT THE REFLECTOR IS 18FT. YOU ARE STILL RIGHT I MEAUSRED IT TO DBI SPECS. I USE A 5000WATT GAMMA ON IT THE SWR IS 1.00.... WHEN I RAN THE PROGRAM IT ASKED ME WHAT FREQ DO I WANT TO USE SO I PUT 27.025 THATS THE CHANNEL I TALK ON AND IT SHOWED ME HOW MUCH MY SWR WOULD BE ON ANOTHER CHANNEL. I'VE HAD GOOD REPORTS ON THE ANTENNA AND ITS DEAD OUT THE BACK WHEN I TURN AWAY FROM OTHER STATIONS I CAN'T EVEN HERE THEM.
 
youngest man,
I'm certainly not disagreeing on what you say you are experiencing. How would I know? I am saying that the 'way' you are expressing yourself is a bit confusing.
For instance, how do you measure anything to 'dBi' specs? I honestly have no idea what you mean by that. I also wonder what 'program' you are using to get the numbers you've gotten. I like 'playing' with 'gadgets' and want to see how it works!
If I had built your antenna I'd be proud of it too. It would certainly make it 'special' as far as I was concerned! But, unfortunately, it really isn't all that 'special' in the radio world (not that you shouldn't be proud of the accomplishment!). Except for the 80+ dB F/B ratio thingy, it's sort of a typical 3 element yagi-uda beam.
- 'Doc

(Don't let me, or anyone else take away your sense of accomplishment. After that, oooo get ready for it - lol !)
 
youngest man said:
I'M NOT ON HERE TO TRY TO SELL THIS ANTENNA I'M ON HERE TO SEE WHAT YOU ALL THINK ABOUT THIS I TALK ON THE 3 ELEMENT ANTENNA THE BOOM IS 13FT 9IN YES YOU ARE RIGHT THE REFLECTOR IS 18FT. YOU ARE STILL RIGHT I MEAUSRED IT TO DBI SPECS. I USE A 5000WATT GAMMA ON IT THE SWR IS 1.00.... WHEN I RAN THE PROGRAM IT ASKED ME WHAT FREQ DO I WANT TO USE SO I PUT 27.025 THATS THE CHANNEL I TALK ON AND IT SHOWED ME HOW MUCH MY SWR WOULD BE ON ANOTHER CHANNEL. I'VE HAD GOOD REPORTS ON THE ANTENNA AND ITS DEAD OUT THE BACK WHEN I TURN AWAY FROM OTHER STATIONS I CAN'T EVEN HERE THEM.
Click to expand...

Well YM, that is what a directional beam is supposed to do, attenuate some of the RF from the opposited and adjacent angles to the front. The variable ranges for doing that and not doing that is however very small. You are basically trying to tell us that you can reproduce the attenuating affects of the noise level of a multi-engine commercial airline on the human ear to zero using your antenna. 85db is not a realistic number in this regard. That even exceeds natures polarity difference (approx 25-30 db) by a very large degree of magnitude and that is not likely.

Since you can't and won't prove anything else to us about your claims or source then just prove the math equation, do the math for us in your post above (THIS EXPLAINS WHAT DBI IS). Then I would be more inclined to believe you really know what you are trying to tell us. Using your three element yagi as A and the isotropic as Q, give us the actual numbers that prove your antenna gains for forward and front to back. That should be easy and not giving us any secrets.

If I was to listen in on the Super Bowl would I hear those guys talking about you as The Man?
 

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