OTA signal with Foiled-Roof sheathing - AVS Forum
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post #1 of 12 Old 07-31-2012, 05:51 AM - Thread Starter
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Hello-thinking of using foil-backed roof sheathing for a new house. It occurred to me that this might interferre with OTA signals (because was thinking of antenna in attic rather than outside)-has anybody had any actual experience with this foiled-roof and how it affects OTA signal?
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post #2 of 12 Old 07-31-2012, 06:37 AM
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Enclosing an antenna in a conductive box will effectively shield it from external signals.
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post #3 of 12 Old 07-31-2012, 06:58 AM
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Reception will suck.

CIAO!

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post #4 of 12 Old 07-31-2012, 07:19 AM
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Mount the antenna outside. It will be better even if you had conventional sheathing.
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post #5 of 12 Old 08-04-2012, 08:59 AM
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Also, be sure the antenna is far above the metal sheathing. You'll need to be about ten feet above it, or mount the antenna on the end of the roof closest to the towers. Nearby metal will de-tune things, and the sheathing will act like a mirror if it's in front of the antenna, causing multipath.

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post #6 of 12 Old 08-04-2012, 09:12 AM
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Even if you weren't using the metal sheathing - I'd recommend putting the antenna outside where it belongs. With the metal sheathing (my siding is the foil covered stuff) - forget about reception unless your antenna is well above the foil.

You CAN put antennas on your owned and/or controlled property...
http://www.fcc.gov/mb/facts/otard.html

Being A Beacon of Knowledge in the darkness of FUD
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post #7 of 12 Old 08-04-2012, 06:03 PM
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I've had some experience with this. In the winter of 2011, a radiant barrier was installed here. I told the people selling this that it would probably harm indoor OTA reception. What happened here after was different reception in different rooms. In a room with a correct facing window, I believe reception is slightly more reliable than before. In rooms without a correct facing window, VHF signals are degraded quite a lot. I receive only 1 of the 2 VHF stations successfully in 1 of the rooms. I'm using a Mohu Leaf in that room because traditional rabbit ears do not work for either VHF station. This leads me to believe that the barrier has made that room noisier in terms of electrical interference. Some UHF signals were harmed in terms of reliability, but others weren't. Some may have been helped.

I'd guess your reception will be less reliable, but it might still be okay. You'd have to try it to find out. VHF will most likely be the most difficult to receive. Good Luck.
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post #8 of 12 Old 08-04-2012, 07:00 PM
 
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Quote:
Originally Posted by deltaguy View Post

I've had some experience with this. In the winter of 2011, a radiant barrier was installed here. I told the people selling this that it would probably harm indoor OTA reception. What happened here after was different reception in different rooms. In a room with a correct facing window, I believe reception is slightly more reliable than before. In rooms without a correct facing window, VHF signals are degraded quite a lot. I receive only 1 of the 2 VHF stations successfully in 1 of the rooms. I'm using a Mohu Leaf in that room because traditional rabbit ears do not work for either VHF station. This leads me to believe that the barrier has made that room noisier in terms of electrical interference. Some UHF signals were harmed in terms of reliability, but others weren't. Some may have been helped.
I'd guess your reception will be less reliable, but it might still be okay. You'd have to try it to find out. VHF will most likely be the most difficult to receive. Good Luck.

A Mohu Leaf antenna is not a VHF antenna anyway.
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post #9 of 12 Old 08-04-2012, 08:42 PM
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In that room, rabbit ears do not work for rf 9 or rf 10. The RS budget doesn't work for those VHFs. A single classic bowtie doesn't work. The Winegard Freevision also doesn't work. A Mant 510 doesn't work as well. The Leaf gets rf 10.

Interestingly, the VHF response from rabbit ears versus the single bowtie is pretty much the same. The rabbit ears are a VHF antenna, and they were measured correctly for rf 9. Why has the Leaf worked, EMI?

With a correct window, the single bowtie gets both rf 9 and rf 10 with higher signal levels than the Leaf.
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post #10 of 12 Old 08-04-2012, 09:24 PM
 
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Quote:
Originally Posted by deltaguy View Post

In that room, rabbit ears do not work for rf 9 or rf 10. The RS budget doesn't work for those VHFs. A single classic bowtie doesn't work. The Winegard Freevision also doesn't work. A Mant 510 doesn't work as well. The Leaf gets rf 10.
Interestingly, the VHF response from rabbit ears versus the single bowtie is pretty much the same. The rabbit ears are a VHF antenna, and they were measured correctly for rf 9. Why has the Leaf worked, EMI?
With a correct window, the single bowtie gets both rf 9 and rf 10 with higher signal levels than the Leaf.

A) Post a TVfool report and maybe I can answer your questions better

B) Rabbit ears are VHF but they also have a gain of less than 2 dB.

C) Even a paper clip can get in Low VHF channel 2 if the signal is strong enough.
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post #11 of 12 Old 08-04-2012, 10:16 PM
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Quote:
Originally Posted by BCF68 View Post

A) Post a TVfool report and maybe I can answer your questions better
B) Rabbit ears are VHF but they also have a gain of less than 2 dB.
C) Even a paper clip can get in Low VHF channel 2 if the signal is strong enough.

My signals are all LOS with noise margins of around 50-55 from the Walnut Grove towers. I suggest EMI, because in part, the rabbit ears and single bowtie both have unshielded twin-lead. The RS budget , Mant 510, and Freevision also have rabbit ears or flat VHF elements. The Leaf is the only antenna without rabbit ears or unshielded cable.

While I haven't tried it, a paper clip in the ANT IN of a 40" plasma television probably has no chance of any useable VHF signals regardless of strength.

edit: useable
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post #12 of 12 Old 08-05-2012, 10:04 AM
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FWIW, we have a metal roof but our antenna is mounted at the apex of the roofline about 10' above and have never seen any degradation in signal, but then again we have LOS for about 50 miles to the antennas with no obstructions.
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