# D*'s OTA Antenna & Multipath Issues



## MoInSTL (Jan 25, 2006)

Couple of quick questions. I live almost on top of the airport in St. Louis and it's causing significant multipath issues. What have others done? I can't be the only one who lives very, very close to a large airport.

I'm not far from the towers which are 12-14 miles away. It's the airport that is causing my Silver Shooter indoor antenna to drop my signals.

D* is coming tomorrow to deliver my HR10- 250 and to install the Eagle Aspen DTV2BUHF which is the mesh 2-bay bow tie. At $50, it is the most cost affective but may be a complete waste of $. I spoke to the company doing the work earlier today and they said they are willing to run the antenna cable separately and directly in. They only carry the DTV 2BUHF. D* no longer uses the clip-on bat wings I read about. 

Local HD channels aren't due here until sometime in May. So even though I realize OTA has less compression I don't want to go crazy with a huge antenna as locals may be fine after all. Then there is the cost. Just trying to figure out the most cost effective solution.

I have done the following:
Checked antenna web and since I'm in the red zone due to the airport they recommend a medium directional antenna.
Checked out the AVS forum
Googled
Checked out Antennas Direct--they recommend a yagi style antenna directional antenna 
Checked out a local dealer, Skywalker Communications. They recommended a Square Shooter for multipath probs.

I joined this forum several years ago when I got one of the first stanalone units but haven't posted in so long I forgot my old username. The forum won't allow me to link any URL until my 5th post.

Thanks in advance!


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## nrc (Nov 17, 1999)

You might dig around to see if you can find beam width data on the Silver Sensor and Square Shooter. Unless the Square Shooter has a tighter beam it probably won't help. 

I have a similar problem with a DB2 and I'm 11 miles from the towers. I get too much multipath on the strongest station. It seems to work better with a UHF loop inside but its a trick keeping it adjusted to get all the other stations well.


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## MNTivoGuy (Oct 21, 2002)

MoInSTL said:


> Local HD channels aren't due here until sometime in May. So even though I realize OTA has less compression I don't want to go crazy with a huge antenna as locals may be fine after all. Then there is the cost. Just trying to figure out the most cost effective solution.


D* adding your locals in HD will not be of any benefit to your HR10-250, as the HR10-250 is not capable of receiving the MPEG4 signal. You will still need an antenna solution to receive the locals in HD through your HD TiVo, even when St. Louis HD locals are added/


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## MoInSTL (Jan 25, 2006)

MNTivoGuy said:


> D* adding your locals in HD will not be of any benefit to your HR10-250, as the HR10-250 is not capable of receiving the MPEG4 signal. You will still need an antenna solution to receive the locals in HD through your HD TiVo, even when St. Louis HD locals are added/


D* already has notes on my account to swap out my HD TiVo and upgrade my dish to the 5 LNB when it's time at no cost. So for now, that isn't a concern. If that was not the case I would have held off on getting it a HD Tivo now.


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## f300v10 (Dec 6, 2004)

If you are try to solve multipath issues, then you need the most directional antenna you can find. If all your OTA channels are broadcasting above channel 10, then I would recommend the channel master 4228. It is an 8 way bowtie, and is one of the best, if not the best antennas out there. You can get one for around $50. I tried an antennas direct yagi, and the 4228 has been better for me. I also have bad multipath issues to deal with.

http://www.solidsignal.com/prod_display.asp?main_cat=03&CAT=&PROD=ANC4228


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## MoInSTL (Jan 25, 2006)

Thanks, but I'm not clear on what you mean by "find beam width data".

If I search just on multipath here it brings up a lot of hits, but not anything that is useful in my situation.



nrc said:


> You might dig around to see if you can find beam width data on the Silver Sensor and Square Shooter. Unless the Square Shooter has a tighter beam it probably won't help.
> 
> I have a similar problem with a DB2 and I'm 11 miles from the towers. I get too much multipath on the strongest station. It seems to work better with a UHF loop inside but its a trick keeping it adjusted to get all the other stations well.


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## GaryD9 (Mar 1, 2002)

MoInSTL said:


> Thanks, but I'm not clear on what you mean by "find beam width data".


http://www.hdtvprimer.com/ANTENNAS/comparing.html

Down in that page, under 'Net Gain for ... UHF antennas' you'll see a list of some, including the DB2, Square shooter, etc. Those links will show you the beam width.

The Squareshooter and silver sensor seem to have similar beam widths. The DB2 (which is similar to the double bow-tie you described) has a smaller width...


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## f300v10 (Dec 6, 2004)

If you check the beam width of the 4228, it is far more directional than either the DB2 or the Squareshooter. Your best chance to reduce multipath is with the most directional (i.e. smallest beam width) antenna you can get. And that assumes that all the stations you are trying to receive are within a few degrees of each other from your location.


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## rich404 (Feb 20, 2002)

I have installers coming on Saturday. Can I ask what you mean by "they said they are willing to run the antenna cable separately and directly in". 

What is the alternative and why is it better to run the cable separately?

Thanks, Rich


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## TheBigDogs (Oct 14, 2004)

MoInSTL said:


> Couple of quick questions. I live almost on top of the airport in St. Louis and it's causing significant multipath issues. What have others done? I can't be the only one who lives very, very close to a large airport.


I live between SFO and SQL and have to contend with SFO's ILS system less than half a mile from my home. Unless it's something the military stuff at STL is using, I can't imagine the airport having much of an impact on your reception.

I started out using a Silver Sensor and it picks up all the Bay Area HD signals. However, I found that it was too directional and I would have to make adjustments to optimize the signal for each station. I replaced the SS with a Jansen TV940A and after a couple of hours found a sweet spot where I pick up every HD signal in the Bay Area with a reading of 75% or higher on the HR10-250 meter.

We actually lose picture from the off course wide bodies passing between the dish and the satellite more often than we lose the OTA HD signal. I'm 15.8 miles from the towers and the indoor antennas work just fine - you've just got to find the right one.

Good luck.


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## A J Ricaud (Jun 25, 2002)

rich404 said:


> I have installers coming on Saturday. Can I ask what you mean by "they said they are willing to run the antenna cable separately and directly in".
> 
> What is the alternative and why is it better to run the cable separately?
> 
> Thanks, Rich


The alternative is to "diplex" the OTA onto one of the satellite lines. This effectively joins OTA/Sat. You then use a second diplexer at the receiver, which splis OTA/Sat.

The advantage: No additional cable to run.

The disadvantages: 
1. More complexity/points of failure--diplexers can be of poor quality; they sometimes fail, making troubleshooting more difficult.
2. Some loss of signal going through the diplexers.
3. If you eventually go to an MPEG-4 receiver/antenna you cannot diplex--a separate OTA coax line is required.

There are probably more but these come to mind.


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## MoInSTL (Jan 25, 2006)

Good list of disadvantages. I wanted mine separate for the reasons you listed and to be able to hook it up different antenna.



A J Ricaud said:


> The alternative is to "diplex" the OTA onto one of the satellite lines. This effectively joins OTA/Sat. You then use a second diplexer at the receiver, which splis OTA/Sat.
> 
> The advantage: No additional cable to run.
> 
> ...


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## TyroneShoes (Sep 6, 2004)

f300v10 said:


> If you are try to solve multipath issues, then you need the most directional antenna you can find. If all your OTA channels are broadcasting above channel 10, then I would recommend the channel master 4228. It is an 8 way bowtie, and is one of the best, if not the best antennas out there. You can get one for around $50. I tried an antennas direct yagi, and the 4228 has been better for me. I also have bad multipath issues to deal with.
> 
> http://www.solidsignal.com/prod_display.asp?main_cat=03&CAT=&PROD=ANC4228


This is terrific advice. A big ditto from me, at least. Also, the 4228 is effective down through channel 7. Real, physical channels, not mapped, virtual channels, BTW.

I guess airplanes could reflect signal and create incidental multipath, but I think you would have to be pretty close. That would make the vertical beam width even more important than the horizontal beam width, but luckily, the 4228 is highly directional in both axes.

If the TV station is receiving their HD signal from the network on a TVRO that is near an airport there can definitely be interference, but that would affect the signal before they even redistribute it. We had to put filters on all of our LNAs for that very reason, as planes emit instrument landing guidance signals that can interfere with the 4GHz band.


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