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Special
Installations
Sometimes it's necessary to go to extraordinary measures
to setup a
satellite system. Line of sight is the biggest issue, if there's no
line of sight on or within 200' of your house, Dish Network will not
install your system for you. This is because Dish Pro and Dish Pro Plus
equipment was not designed to work over more than 200' of RG-6 cable.
The noise from traveling through that much cabling damages the signal
too badly for the receiver to make sense of it.
You'll need to determine what orbital locations you can
or can't
receive, and decide whether you'll be able to live without them. Since
Dish has two separate sets of satellites that duplicate the signal,
solving the problem might be as simple as an "arc flip". If you can't
get the western arc of 110°/119°/129°, try the eastern arc
at 72.7°/61.5° or vice versa. Local channels for certain
markets may only be available on one or the other, if that's the case
you'll need to put up an over-the-air antenna if you want to receive
them. The eastern arc only works with ViP receivers, you'll have to
upgrade any SD receivers when going from western to eastern.
Wing Dishes
If you can't get all of the satellites in either arc
from any single
location, you can use multiple dishes. Say you have a clear LOS to
110° and 119° from one corner of your house, but NLOS to
129°, and your back yard has a clear LOS to 129° but NLOS to
110° or 119°. You could mount a Dish 500 on the corner of your
house and a Dish 300 in the back yard. You can even use three separate
Dish 300s and connect them to a multiswitch.
The Hard Way
The primary cause of poor line of sight is tree growth.
If the trees
are on your property, the easiest way to deal with it is to cut them
down. If your only clear LOS is over 200' from the house, you'll have
to do it the hard way. This was a big problem for me when I was
installing dishes, since the 129° orbital is only 23° above the
horizon here and is the only satellite that carried the local networks.
Mount the dish to a pole somewhere with a clear line of
sight. In this
case we'll say it's in the back yard, 400' from the house. The most
straightforward way of getting the signal to the house is to use RG-11
grade cable. The issue is that RG-11 is really expensive, a couple of
hundred bucks for a 500' spool, compared to about $40 for the same
amount of RG-6, and requires special connectors and tools.
The other option is to use amplifiers and solid copper
RG-6 cable. Buy
good quality inline satellite IF amplifiers rated for 950-2150 MHz.
Good brands include Sonora, Cal Amp, Blonder Tongue, and Eagle Aspen,
everything else is crap. Solid copper cable is required here because
the LNBs, switches and amplifiers are all powered by the satellite
receiver or power inserter. Normal RG-6 has a copper plated steel
center conductor, which allows the voltage and current to drop too low
to successfully power all of the downline equipment.
Cut the solid copper cable into 100' lengths. For our
example we'll
need four of these. Use good quality compression connectors to
terminate them. Hammer stakes into the ground every 100' between the
house and dish and mount a weatherproof plastic box to each one.
Connect one of your inline amplifiers at the dish, and put one in each
of your plastic boxes, every 100'. The amplifiers will lower the
carrier/noise ratio slightly but should keep the signal/noise ratio low
enough that it never dips below the critical limit of -50dBm. If you
have a signal meter that shows S/N ratio, it should be higher than
-48dBm behind the receiver.
For distances over 400'
If your dish is even further than 400 feet from your
house, you should
strongly consider using "legacy" equipment. The maximum frequency
output by a legacy LNB is less than half the maximum frequency of Dish
Pro/DPP equipment, and it usually has a significantly lower noise
figure, meaning it will travel more easily over the same cable. Signal
to noise level measured at the dish for brand new Dish Pro equipment is
about -30dBm and gets slightly worse as the LNB ages. I tested three
legacy compatible LNBs, a Dish Network branded LNB made by Echostar, a
Cal Amp 150517 dual output DBS LNB, and the DBS side of the Invacom
Quad. Results are below, decibels are logarithmic, so every three dB
represents a doubling of signal strength.
LNB
|
Dish
Pro
|
Dish
Legacy
|
Cal
Amp
|
Invacom
|
SNR
@
dish
|
-31.4dBm
|
-27.4dBm
|
-23.4dBm
|
-22.8dBm
|
As you can see the Invacom LNB came out miles ahead with
an SNR almost
six times as high as the Dish Pro version. For more insurance, consider
using a larger dish, such as a Super Dish or a generic 70cm dish. If
you already have a C-band dish, just replace the LNB with a DBS LNB,
which gives exceptional performance. Using a larger dish will increase
the carrier/noise ratio (how much signal is received by the LNB) which
will also increase the signal/noise ratio (how much signal is output by
the LNB).
|