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Pensacola, FL: antenna install scenario

post #1 of 6
Thread Starter 
My friend was using a decent set of rabbit ears (http://i302.photobucket.com/albums/nn88/EscapeVelo/IMG_0016.jpg) but wanted better reception. For best reception we could have used a pole-mounted outdoor directional antenna, but we didn't want to worry about lightning strikes and we already had a bigger indoor/outdoor omni-directional antenna at our disposal, so we used it. (I think the antenna is an RCA ANT806, as seen here: http://i302.photobucket.com/albums/nn88/EscapeVelo/IMG_0152.jpg)

There is lots of blown-in insulation in the attic, makeing it difficult to work up there, so instead we mounted it under the eave right outside the wall where the TV is. I mounted it a bit lower so the eave might not interfere as much with the signal.

The cable company already has a line coming into the wall in the same spot, so I drilled right above it and used a dual coax wall plate. The run is only about 6-8 ft.

We didn't know what kind of reception we would have, and the cable was about 15-20 ft so we could later run it into the attic if desired, so I tightly rolled the excess and stuffed it inside the wall.

When I unplugged the rabbit ears and plugged in the new antenna, we lost at least 1 channel. Then I plugged in a small amplifier box (pictured at left with jpg linked above) in-line next to the tv and we got some extra channels and everything comes in great. I don't know what kind of reception we could have achieved just by adding the signal amplifier to the rabbit ears.



So my questions are:

1) How do you deal with lightning when mounting an antenna on a pole? (sort of a moot point)

2) Was it good to mount the antenna about 8 inches below the eave to put it more "in the clear" or would it be just as good tucked right up underneath it?

3) Is it okay to roll up an extra 10 ft of cable and stuff it into the wall? (kind of doubtful on this)

4) How much benefit are we really getting from the new antenna and how much is likely coming from the amplifier?

5) Does the amplifier neeed to go near the antenna, near the tv, or does it matter? (Does it push a good signal, or does it restore a faded signal? Or am I thinking in the wrong way?)



My theory is that the new antenna IS picking up a better signal with more channels, and that my 10 ft of tightly rolled cable inside the wall is killing it, and the amplifier is bringing it back, and that the amplifier applied to the rabbit ears probably wouldn't have done much good.

Also I bought some u-shaped cable clips with nails, but they won't go into the brick and they're too short to reach the mortar. The existing cable from the cable company looks to use the same clips but the nails are in the brick. How does that work? There are also a couple of clips in the mortar, but with screws instead of nails. Any tips?



EDIT:

Location: Pensacola, FL
TV Fool: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d1dda02f6028807


Edited by GrandPixel - 1/24/13 at 1:40pm
post #2 of 6
You should enter your location into www.tvfool.com and then copy/paste the results URL (web address) into a post so we can determine whether strong signal overload of ANT806's Preamp is a possible problem...weaker stations can be blocked by intermodulation noise products.

You should also recognize that you are comparing two very mediocre antennas with hit and miss coverage across the VHF and UHF Bands...something the manufacturers refuse to reveal in their (lack of) specifications....so each antenna will have (possibly widely) varying Gain response on different channels. After we see your TVFool results, it MAY be better if you used a REAL outdoor antenna and NO Preamp.

The mount or mast of ANY outdoor antenna must have a NEC compliant ground wire to drain off electrostatic charge buildup due to wind passing across the antenna (like shoes shuffling across a carpet)....and if hit with a direct lightning strike, provide a direct ionization path to ground as the copper wire is vaporized.

Loss AFTER the Preamp due to the Coax, Splitters (typ. 4 dB, if used) and (typ. 5-10 dB) Tuner Noise Figure are REDUCED by the amount of Gain in the Preamp. So a Preamp located as close as possible to the antenna "typically" improves the overall sensitivity by about 10 dB.....but ONLY IF IT ISN'T OVERLOADED....which is why I prepared the "DTV Preamp Signal Overload Calculator" spread sheet (see link at bottom of this post).

Excess coax inside the wall shouldn't be much of a problem. Antenna placement is all about LOCATION, LOCATION, LOCATION:
http://www.hdtvprimer.com/antennas/siting.html
Unfortunately, we can't "see" the sweet spots with our eyes, so finding a good location requires a lot of trial and error....
Edited by holl_ands - 1/24/13 at 1:11pm
post #3 of 6
Thread Starter 
Original post edited to include tv fool and location.
post #4 of 6
So my questions are:

1) How do you deal with lightning when mounting an antenna on a pole? (sort of a moot point)
Need to run at least a #8 solid bare copper from the mast of the antenna and grounding block of the coax to the existing electrical service ground rod of your house

2) Was it good to mount the antenna about 8 inches below the eave to put it more "in the clear" or would it be just as good tucked right up underneath
As mentioned, the antennas you are using are mediocre at best. Ideally, it should be mounted on the roof.

3) Is it okay to roll up an extra 10 ft of cable and stuff it into the wall? (kind of doubtful on )
Probably not going to affect it too much

4) How much benefit are we really getting from the new antenna and how much is likely coming from the amp
Well you put the antenna outside which is good, but the type of antenna you put outside is nothing great, so it's a wash

5) Does the amplifier neeed to go near the antenna, near the tv, or does it matter? (Does it push a good signal, or does it restore a faded signal? Or am I thinking in the wrong way?)
Ideally it should go close to the antenna


Based on your tvfool report, all you need is a UHF antenna ( assuming you do not care about WBQP VHF 12, which you should pick up anyway with a UHF antenna only a mile away).
Something like this from radio Shack should be fine:
http://www.radioshack.com/product/index.jsp?productId=3766859&filterName=Type&filterValue=UHF+only#showFullReviews

If you want to keep your current RCA, make sure it is pointing to the WNW where the stations are. And see if you can maybe mount it higher say in the attic.
post #5 of 6
Your TVFool results show MANY, VERY STRONG signals....so you CAN NOT use a Preamp.
So you need a somewhat more powerful Roof Mounted UHF Antenna, like a 2-Bay or 4-Bay Bowtie
or A-D C2 or C4.
post #6 of 6
Since your only Fox affiliate is WALA on VHF channel 9 which is 37 miles away, you're going to need something with a VHF capability such as a C2V, ANT751, HBU22, or 7694 (or similar).

But, no pre-amps allowed!
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