Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

FM does it with frequency!
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Paul678
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Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by Paul678 » Wed Nov 02, 2016 4:25 am

I have a friend of mine who builds directional FM antennas, which he optimizes with a
ham radio program called Yagi Optimizer.

There is an option in the program to utilize two Yagi-Uda antennas "stacked" one on top of the other,
with a 1/2 wavelength phasing harness between them, which essentially creates a two bay antenna.

According to him, the program calculates for 100 Ohms on each antenna, which are placed in parallel
to get the 50 Ohms. In other words, there is no impedance transformation using the coax harness.

I have previously use a Comet 5/8ths, but that was on a location that had much better HAAT.

My new location is much lower in altitude, so I'm going to have to increase the gain in the horizontal
plane, and also get a more powerful transmitter.

Any thoughts on this is greatly appreciated.....

Kelly
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by Kelly » Wed Nov 02, 2016 6:56 am

Is this for a licensed facility, or just talking about theory? Reason for asking; for broadcast anyway, your antenna must meet the gain and radiation limits of your license or C.P. Depending on the approved coverage, a homemade antenna array may not fit the bill.

Your comments about how one would combine stacked yagi's is essentially how it's done, but is not a typical design used for the FM broadcast band.
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TPT
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by TPT » Wed Nov 02, 2016 7:01 am

Might be for a translator--Commision more flexible there.

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Deep Thought
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by Deep Thought » Wed Nov 02, 2016 9:49 am

At the bare minimum you'll need the measured horizontal plane radiation pattern and the power gain referenced to a free-space dipole, which are provided by the manufacturer. Without those you won't be able to use them even for a translator.

I suspect this is one for some sort of 'unlicensed service'.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

Paul678
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by Paul678 » Wed Nov 02, 2016 1:03 pm

Deep Thought wrote:At the bare minimum you'll need the measured horizontal plane radiation pattern and the power gain referenced to a free-space dipole, which are provided by the manufacturer. Without those you won't be able to use them even for a translator.

I suspect this is one for some sort of 'unlicensed service'.
I like to think in terms of dBi, or gain over ideal isotropic radiator.

But yes, the industry standard is dBd, or gain compared to a dipole.

Ok, it looks like everyone here buys their commercial antennas off the shelf,,,wrong forum!

I was mainly seeing if anyone has experience rolling their own antennas using the Yagi Optimizer program. I will try a ham radio forum instead.

Thanks anyways! :)

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Deep Thought
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by Deep Thought » Wed Nov 02, 2016 1:39 pm

If you are using this for a Part 73 or Part 74 service, you'll need to provide the pattern documentation I mentioned above. If you can't do that, you can't use it.

But I suspect this is for a pirate anyway.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

Kelly
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by Kelly » Wed Nov 02, 2016 5:04 pm

That's my guess too Mark. Either that, or another LPFM licensee potentially going rogue.
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Re: Anyone Have Experience with Stacked Yagi Antennas, and the Yagi Optimizer Program?

Post by NECRAT » Wed Nov 02, 2016 5:17 pm

I sent a message to the OP to clarify his use. Based on his response to the PM, will determine if this thread gets opened up again or not.
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