Correct Spacing for Stacking XG91s - AVS Forum
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Old 03-16-2013, 06:39 PM - Thread Starter
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Hi All,

I have read everything from 23 inches (the rear reflectors would be about an inch apart) to 40 inches for stacking XG91s. Anyone have any experience with this and what was your stacking distance.

Thanks in advance for your help.
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Old 03-18-2013, 07:33 AM
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Hi All,

I have read everything from 23 inches (the rear reflectors would be about an inch apart) to 40 inches for stacking XG91s. Anyone have any experience with this and what was your stacking distance.

Thanks in advance for your help.

I've used Triax Unix 100 antennas (almost identical to the XG91s) for several years and also the Triax Unix 100 Band A antennas (the same similar antennas except cut for U.S. channels 14-36.....a little longer length antenna plus a little higher gain for these channels). One of my mounting arms is separated by 40 inches (from center to center of antenna) and the other one is separated by 41 1/2 inches. I picked these up from another TV DXer in my area and he has tried a number of various combinations of antennas and stacking distances. This is the stacking range he found to work the best. I did a little testing with various stacking distances and this is the same range I found to work best, too. Good luck with your stacking project.
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Old 03-18-2013, 08:00 AM
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Now you just need to stack about nine of those Triax FM Yagi's and get in to FM Radio DX, too.
(I'm assuming you may have seen the legendary photo of a Swedish FM DX'ers array, some place on the net.)

Nice setup smile.gif .

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Old 03-18-2013, 04:29 PM
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Now you just need to stack about nine of those Triax FM Yagi's and get in to FM Radio DX, too.
(I'm assuming you may have seen the legendary photo of a Swedish FM DX'ers array, some place on the net.)

Nice setup smile.gif .

Thanks. I still have all the Triax UHF antennas but I'm currently using a Finco P-7 UHF antenna (7 ft. parabolic - pic attached) for DTV DX. It was discontinued years ago but I was lucky enough to location a new one, still in the box, a couple years ago.

As for FM DXing, I have been thinking of trying that again after getting away from it for many years. Living only 5 miles from the local antenna farm is bad enough for DXing DTV but even more difficult for FM DXing. I recently acquired an original Channel Master Stereo Probe FM antenna (11.5 ft. in length) from a friend. He and I originally mounted it on the top of his 48-ft. tower in 1975. It was used for about 15 years and then taken down and stored in an attic, so it's in good shape for its age. With it hooked to a new Harman Kardon AVR, FM reception is quite good. We'll see for sure within the next few months. Tropo season is coming.
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Old 03-18-2013, 10:10 PM
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You would think some antenna company would consider manufacturing a parabolic antenna again. But the new Channel Master does not make any of its original designs anymore, just a few Chinese imitations. And Antennacraft no longer seems interested either in bringing back their parabolic version. And I guess Antennas Direct and Winegard don't appear to be interested in the concept as well. But those Finco/Channel Master/Antennacraft parabolics were arguably the best performing consumer grade UHF antennas ever made. Wish I could find one somewhere. But I am just glad I did get my hands on 2 new 4248s and a used but good 4257 UHF Diamond antenna a few years ago. All original Channel Master designs no longer made. Perform very well.
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Old 03-18-2013, 10:31 PM
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Do you think you could substitute a 91XG balun from Antennas Direct on those Triax 100 antennas? The Triax do not use the normal female connector for the coax cable and I don't quite understand how to connect the cable into the Triax balun correctly. And where can you order a Triax in the US? I imagine they may be expensive to import, so I will probably just stick with the 91XG on my next application.
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Old 03-19-2013, 08:05 AM
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Do you think you could substitute a 91XG balun from Antennas Direct on those Triax 100 antennas? The Triax do not use the normal female connector for the coax cable and I don't quite understand how to connect the cable into the Triax balun correctly. And where can you order a Triax in the US? I imagine they may be expensive to import, so I will probably just stick with the 91XG on my next application.

Good questions, but I have no definitive answers. The end of the coaxial cable is bare-wired connected inside the housing on the Triax antennas. It can be a little tricky to do, but once you have a good connection inside the unit, it is pretty much good to go for some time. And I've never ordered a Triax, as I bought mine from another TV DXer who did the ordering. I know he had to look around and make some phone calls before ordering. And, yes, they were somewhat costly due to the high shipping expense.

Yes, too bad that with so many DTV stations now using UHF channels that at least one company has not stepped up to offer a couple parabolic antennas.
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Old 03-19-2013, 08:07 AM
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I guess Antennas Direct and Winegard don't appear to be interested in the concept as well.

To what end? The economics make no sense.

It would cost several tens of thousands of dollars in initial engineering and tooling costs, then manufacturing, shipping, inventory, marketing, order fulfillment, shipping (again), customer support, returns, warranty service, etc, etc for a product that would probably sell, at most, several dozen units a year at a cost that would have to far exceed the highest price point in our current product lineup .

Now, if you can figure out how to do all that and make a profit, please let us know. The ones who dropped this type of product in the past figured it out long ago.

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Old 03-19-2013, 09:03 AM
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You can make one with a microwave or satellite dish, but the wind-loading is pretty high.
Kent Parsons has built some, using a UHF yagi, offset to the side, for the feed. They are mounted on huge tower legs, though.

For most commercial purposes, Scala/Kathrein makes a Paraflector. It's a single-channel unit, but works pretty well across +/- 2 or 3 channels. After that, you need a different balun/feed assembly.


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Old 03-19-2013, 05:41 PM
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To what end? The economics make no sense.

It would cost several tens of thousands of dollars in initial engineering and tooling costs, then manufacturing, shipping, inventory, marketing, order fulfillment, shipping (again), customer support, returns, warranty service, etc, etc for a product that would probably sell, at most, several dozen units a year at a cost that would have to far exceed the highest price point in our current product lineup .

Now, if you can figure out how to do all that and make a profit, please let us know. The ones who dropped this type of product in the past figured it out long ago.
Well you had to market and produce the new version of the 8-Bay, so I guess I was hoping the costs would not really be that much more. But I guess I was wrong there. I guess the best option would now be to combine 2 DB8s or 2 Super Gray Hoverman's together in an extreme fringe application.
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Old 03-20-2013, 10:08 AM
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Producing the DB8e built on work that already had been done and there was little incremental cost as compared to designing a completely new product from scratch. It was the logical progression of completing our bowtie family's conversion to the post-transition channel band, something internet commentators have been complaining about for several years. I guess you can't please everyone.

Do a basic business plan for what you want. Say it costs $50K for the basic R&D and to tool up a production line to build it. Assume that raw materials, production costs (materials and labor), and inbound shipping will run $100 per unit just to get it into a warehouse. Now, for a product that might sell 50 units per year, ask your self the following questions:

1) How many should I order from the factory? Heck, we've got some slow-movers in inventory that have been there for 5-8 years and storage is not free.
2) How much should it be sold for (remember the back-end and support costs and maybe a profit )? Then, listen to the internet commentators complain about the cost!
3) Will money EVER be made from this product. If so, when? How much? Will this project bankrupt the company if it fails?

That's the "real world" math and some of the real word questions that are involved.

Seriously, if there was money to be made, there's be someone making money doing such a behemoth antenna.

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Old 03-20-2013, 01:58 PM
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Wade Antenna does sell wideband UHF parabolic antennas. They do have to be mounted using 2" to 4" pipe or on a tower and the cost I believe is in the thousands of dollars.
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Old 03-20-2013, 07:14 PM
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Wade Antenna does sell wideband UHF parabolic antennas. They do have to be mounted using 2" to 4" pipe or on a tower and the cost I believe is in the thousands of dollars.
Well I can't afford to spend thousands of dollars on an antenna. About $100 is the most I would like to spend for a very good antenna. And it looks like the new DB8e is a very good upgraded design, although a bit pricey at the moment. But I guess they have to cover their costs and make a profit. So not complaining there. I think their Clearstreams and 91XG are great antennas. And I already have old and new Channel Master 4228 versions, so I am covered in that category for now. But I really would like to try a new DB8e at some point when my budget allows.
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