"Mark Lloyd" wrote in message
...
On Wed, 6 Jun 2007 08:43:48 -0600, "mg"
wrote:
[snip]
I'm on my third DirecTV dish now and I was able to install
the first two myself.
I installed my dishes myself, until I got HD service (I
did NOT need a
5-LNB dish). Then the installer (which I didn't need at
all, at least
if they'd send me the receiver) replaced my working 3-dish
setup with
a 3-LNB dish (that did NOT improve anything).
With the first two, my technique was
to use the audible signal strength meter on the TV by
putting the telephone next to the TV and then calling
myself
on my cell phone. Another technique I have used is to have
an assistant watch the meter on the TV while talking to
him
on the cell phone.
Mine was closer, so I didn't need the phones. I just
turned up the TV
volume and left the door open.
BTW, I suppose you had a headset for your cell phone.
Damn! You know I do have a headset that I use for my
cordless phone that would probably work, but I was too dumb
to think of it. Actually, I just spend an hour or two
yesterday trying to adjust my Ka/Ku antenna with no luck.
I'm not sure if it's broke after the roofers got through
kicking it around or maybe there's a small blip on the
signal strength bar on the TV that I'm not hearing with the
audio. I have a technician coming out Friday morning. It
only costs $49 and I've decided that it's worth it.
As DirecTV adds more satellites, though, the margin for
error in pointing the dish becomes smaller. Speaking
hypothetically, the very first dish might have allowed for
a
margin of error of 3 or 4 degrees in the azimuth setting,
but the new "Ka/Ku" antennas probably only allow an error
of
a small fraction of one degree. This antenna,
incidentally,
receives signals from 5 different satellites
Actually 5 different satellite locations. There are 4
satellites at
the main (101) location, and there will me multiple
satellites at the
new (Ka) locations.
I didn't know that. I suppose it makes sense, though.
Of the 101-degree satellites, 3 are older ones with 16
transponders
each (since there's a limit of 32 transponder channels,
some must not
be in use), and the new spotbeam satellite with more
transponders (I'm
not sure of the exact number, although I think that
information is
available somewhere). 6 transponder channels
(4,12,18,20,26,28) are
used for spotbeams.
over a
20-degree span.
Another problem (obviously) with the new antenna is that
it
has to be mounted so that it's very solid and very stable
and it typically requires 2 separate braces to hold it in
place. This means that not only is the pointing of the
antenna critical, but the mechanical installation is also.
In addition, the LNBs are probably relatively delicate and
the dish itself obviously isn't going to work if it's bent
even slightly.
In short, roofers are going to have a significant problem
with these antennas and I'm betting that most of them
don't
even know it yet.
When I had my roof replaced, the roofer failed to replace
the dish
properly. It's better if you can avoid putting it on the
roof.
Yah, I know. My neighbor has a big wall of trees, though,
just south of my house. When I originally signed up for
DirecTV, I build a triangle, with the proper angle on it,
out of some scrap pieces of wood and stuck a level on it
with some tie wraps. Then I aimed along the top of the
triangle to insure that I had clearance. I'm guessing I have
about 20 feet on clearance, but there's no place else to put
it.
Incidentally, the previous generation of DirecTV antennas
also required a tilt adjustment,
The "previous generation" being 3-LNB dishes. Tilt is for
multi-satellite dishes (and did not apply to the original
1-sat ones).
That's true. The tilt adjustment on the new Ka/Ku dish, by
the way, is the only adjustment that doesn't use a
fine-threaded screw for the final adjustment. Adjusting the
azimuth and elevation on this new one is a little bit like
adjusting the idling speed on an old carburator.
BTW, the dish isn't the antenna. It's just a reflector.
The antenna is
very small, and located within the LNB housing.
I'm not sure if I agree although you might be right. With
the well-known Yagi-Uda, VHF antennas, for instance, there
is a reflector on the back and then a bunch of directors on
the front that focus the waves onto the receiving or driven
element. However, the entire assembly is still called an
"antenna". I wonder what the antenna inside looks like and
if it just consists of one element or some sort of an array?
I suppose it's mounted on a small circuit board.
but that wasn't really a
problem. The problem is with degree of accuracy required
and
not the number of adjustments that have to be made.
--
Mark Lloyd
http://notstupid.laughingsquid.com
"Properly read, the Bible is the most potent
force for atheism ever conceived." -- Isaac Asimov
That's true. Leviticus 15:19-30 comes to mind for instance.