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Old 27-Jan-2011, 2:52 PM   #1
txv11
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Attic Antenna Help in Cleveland, OH

I am trying to "cut the cable" and have been tinkering with antennas in my attic.

My TV Fool Report can be found here:
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I created a 4 Bay Bowtie antenna and get results that I can't quite explain. My setup includes a 50' coax run to a 2 way splitter, which then goes into a Silicondust HDHomerun dual tuner. My roof is slate, no foil insulation. I can reliably get real channels 8, 15, and 17. Depending on where the antenna is pointed (with only slight variation) I can reliably get real channel 10 or 26, but typically not both. I'm most interested in receiving the channels 228 degrees to 231 degrees. If I could get the second PBS station at 191 degrees that would be nice, but I recognize it may not be possible.

I also recognize that being a DIY antenna it may not be optimal. But the results seem a little strange. I'm looking for a recommendation on an antenna that would allow me to reliably receive the channels I mentioned above.

Thanks.
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Old 27-Jan-2011, 5:11 PM   #2
GroundUrMast
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Has this antenna produced reliable reception when tested at ground level, outdoors? Attic mounting just cripples it's performance more. None of the 4-bay DIY designs I have seen are optimized for reception of real channels 2 through 13. An ANT-751, HBU-22 or HBU-33 would be more than enough antenna for your location.

A cheap set of non-amplified rabbit-ears should provide good results according to the TVF report you have.

You can determine if your building has signal blocking properties by comparing the signal strength and quality with the same antenna inside then outdoors. The Silicondust HDHR has very good signal metering. I own several HDHR's and all are less forgiving than the built-in tuners in my HD flat-screen receivers. I like my HDHR's but need to feed them a slightly better quality signal than the other tuners. (Using the HDHomerun Config GUI, I pay more attention to "Signal Quality %" than "Signal Strength %" when I am adjusting antenna location or aim.)
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Last edited by GroundUrMast; 27-Jan-2011 at 5:21 PM.
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Old 27-Jan-2011, 8:11 PM   #3
John Candle
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Tv Antennas and Reception

Tv transmissions are Strong , the ones in green are LOS Line Of Sight , a Simple indoor antenna should get you many channels. http://forum.tvfool.com/showthread.php?t=233 . . Read and understand this about Real Digital Tv Channels and Virtual Digital Tv Channels. And analog Tv channels http://forum.tvfool.com/showthread.php?t=695 Here is how to point Tv antennas http://www.kyes.com/antenna/pointing/pointing.html

Last edited by John Candle; 28-Jan-2011 at 8:26 PM.
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Old 28-Jan-2011, 1:00 PM   #4
txv11
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Thanks for the advice. I know that the signals are strong and I'm not far away from the stations, but the reception seems to be less than I would expect. I've tried a couple of simple indoor antennas just on the ground floor with little success. Since it's cold and snowy I haven't spent anytime trying an outdoor solution. I live in an older, densely populated neighborhood with two story + attic homes and the direction for the transmission towers is straight at a small hill and houses/trees across the street. I suspect that I'm suffering from multipath problems, but not sure if there's a way to verify that. I should also say that last night all of the channels came in with the lowest signal measurements being around 70% signal quality. I know that my DIY antenna is designed for UHF, but find it a little strange that one of the High-VHF channels (Real Channel 8) is one of the best. Lastly I'm puzzled by what seems to be very strong directionality of the antenna. If I rotate the antenna slightly (10 degrees or so), the signal readings change quite dramatically on some channels. I guess this is why I think I'm suffering from multipath. Would a more highly directional antenna help in a suspected multipath situation where you are relatively close to the transmission towers? Thanks again for the help. I know how antennas can be affected dramatically by small things and I've learned a lot on these forums.
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Old 28-Jan-2011, 1:53 PM   #5
Dave Loudin
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If your DIY design uses 7" whiskers, then I'm not surprised that you are having trouble. That design, as documented by several YouTube videos and at Make: magazine's site, will suffer from high VSWR, leaving you open to many problems. The optimum bowtie array design for high-VHF/UHF is documented here.
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Old 28-Jan-2011, 8:23 PM   #6
John Candle
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Tv Antennas and Reception

This type of antenna without a reflector receives 2 directions , the least amount of reception is signals that are at the sides of the antenna , thats looking directly at the end of the antenna wires. Here is how to point Tv antennas http://www.kyes.com/antenna/pointing/pointing.html

Last edited by John Candle; 29-Jan-2011 at 5:42 AM.
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Old 28-Jan-2011, 8:42 PM   #7
John Candle
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Tv Antennas and Reception

UHF antennas will receive 2 thru 6 and 7 thru 13 when the antenna is close to transmitters and the signals are strong as in your case. It helps reception if a Tv antenna is placed at a window that faces the Tv transmitters , and if the window does not have real metal window screen. These old Row Houses had or may still have real metal window screens. In an attempt to improve/update the look of these old Row Houses some have been wrapped with stucko WIRE and had stucko put on. This does not improve the look of the house it makes it look worse and the stucko WIRE blocks Tv signals.

Last edited by John Candle; 28-Jan-2011 at 9:14 PM.
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Old 28-Jan-2011, 9:35 PM   #8
GroundUrMast
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VHF High Band DIY

Here is a very simple knock-off of a set of rabbit ears.
Attached Files
File Type: pdf VHF High Band Dipole.pdf (19.2 KB, 630 views)
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