OTA Antenna Installation Guide for HDTV Reception: Placement, Preamps, Cabling, and Grounding
By Dale Cripps · 2001–2004
Summary
This practical guide walks HDTV viewers through selecting, installing, and grounding an outdoor OTA antenna using AntennaWeb.org to identify local DTV channels and determine signal requirements. It covers preamp placement, RG6 cabling, rotor considerations, attic versus outdoor mounting tradeoffs, and proper grounding rod installation to protect against lightning damage.
Source documentcirca 2001–2004preserved as-is
THE ANTENNA
An antenna is excited by radio waves which produces a certain level of
signal. They come in all kinds of sizes and shapes. The most common
are VHF/FM/UHF combos and UHF only. HDTV reception can be either UHF
or VHF. How much signal you will need depends on your distance,
elevation and buildings within 4 blocks. The key is to get the signal
level just right. Too little or too much can cause problems.
Go
to http://www.antennaweb.org/aw/welcome.asp
and click on "choose an antenna". Inserting your address is
recommended or use zip code and answer the two remaining questions.
Click submit. You now have a listing of all stations you have a chance
of receiving and print it. At the top of the listing click on "map
station distribution" and print it also. The stations on the bottom
are the furthest away and you may not even recognize them. From the
bottom work your way up to your local analog stations and click on one
of them in the same color group. Do not misunderstand this step and
click on the DTV channels. You will need to use your NTSC stations as
your antenna selector guide for now since they are not transmitting
DTV at full power yet. Now you have information that tells you what
antenna you need, if a preamp is required, where the transmitters are
and the "real" DTV channel numbers. The antenna is cheap. Major
expenses will be all the other stuff and your labor. If all the
transmitters are basically from one direction you probably will not
need a rotor. If not make a rotor part of the budget because most
installations need it to avoid problems or to get that tough to
receive channel. Use RG6 cable and the proper connectors. It is
assumed you know how to properly terminate the cable.
The FCC has legally allowed
you to mount an outside RF antenna of any size up to 12 feet above the
roof line regardless of your home owners association rules and
regulations. I am not providing legal counsel but based on some people
who lost such a case and take the antenna down I suggest you use this
option as a last resort. For more information contact the FCC or check
this link http://www.fcc.gov/mb/facts/otard.html
Buying the antenna and
associated stuff was the easy part. Installing it is work. In the
installation make allowances for the possible rotor and wiring ‑ you
will appreciate this step later if you need one. Once you get the
system installed changing the antenna itself is easy and cheap so
don't sweat what kind of antenna you bought too much. Many people have
had success mounting the antenna in the attic. The performance you
will get varies but bear in mind that the materials used for your roof
could kill your signal. Humidity can also have a big effect on the
reception when using the attic. Bottom line is installing it outside
is always preferable over the attic. If you have a
multi
level dwelling and live in a subdivision that does not allow roof top
antennas you may be able to mount it under a rear deck which is still
better than the attic ( worked great for me ‑ might not for you )or in
the backyard. Place the antenna for the least obstruction of anything
between it and the direction it will face ( if possible ) and point it
towards that direction using the "map" you printed out. Pay attention
to boots, covers and seals which keep out the elements. Preamps come
in 2 sections and I recommend it have variable gain rather than fixed.
One part is the actual preamp and it belongs on the antenna mast as
close to the antenna as reasonably possible, NOT in the house. Allow
SLACK for turning the antenna by hand or with a rotor. The other part
is the power supply and that is what goes in the house. Make sure it
is accessible and within VIEW of the TV so you can tweak the gain. It
must have live AC at all times so DO NOT use a switched outlet.
Terminate the cable PROPERLY with the CORRECT connectors with the
proper CRIMPING tools or you will detune the system. NO, you can't
just use pliers and "squish" it or "pinch" it on.
Another issue is grounding to
protect you and your property from lightning damage. If you installed
the antenna in the attic then skip this paragraph since grounding is not
required. For outside antennas grounding the mast and running the
antenna cable through a grounding block is required by code. You will
need an 8 foot copper grounding rod, grounding block, RG6 coax ground
wire attached and 2 ..... To install this grounding system you simply
run your coax to the antenna or preamp. Strip the ground wire off the
coax to about a foot above the base where you will have installed the
___- and attach the ground wire to it. Determine your cable run and
where a good place will be for the grounding rod and block. Now comes
the really hard part which is to drive that 8 foot rod into the ground
about 6-7 feet. Attach the _____ to the grounding rod. Install the
grounding block on the house or some other support near the rod. Take
the extra grounding wire and connect the grounding block to the ______
on the rod. On the cable determine where you are going to cut and
terminate for the grounding block and cut just the coax not the ground
wire. From that point determine how much grounding wire you will need to
from the termination to the rod and strip that off the other side of the
cable and cut the ground wire from it. Now terminate and install the
coax to the input of the grounding block and the grounding wire to the
____ on the grounding rod. You are now fully grounded. Take the other
end of the cable and terminate and install on the output of the
grounding block and complete the run to the TV or preamp power supply.