Sun Spots affecting my digital cable?
Mark Zmyewski
Computer Science. Maybe someone can help me. My digital cable
(Knology) has been acting weird lately. The picture stops, then
starts, then stops again, updates half of the screen, then a
second later updates the second half of the screen, etc. This
doesn't happen all the time, but it does happen enough that I
called Knology. A guy came out and replaced the cable box.
However, that night, it started all over again. It's been about
one week and I decided to call again. The woman that fielded
my call told me that they get a lot of complaints in April and
October because that is when sun spots are most frequent. I
know that sun spots can cause problems with radio signals and
other things, but digital cable? Can someone enlighten me?
-Mark Zmyewski
Don Roden
>
> Ok, I admit it, I'm not a solar expert. The woman that fielded
> my call told me that they get a lot of complaints in April and
> October because that is when sun spots are most frequent. I
> know that sun spots can cause problems with radio signals and
> other things, but digital cable? Can someone enlighten me?
>
> -Mark Zmyewski
The woman knew nothing about sunspots.
There is however, a seasonal occurrence (fall and spring) where the
sun is directly behind the digital satellite that feeds the ground based
receive dishes. The Sun is a huge "RF noise generator" and as the earth
and the satellite rotate, there is a 30 minute "window" where the
Sun's energy overpowers the sensitive receive circuits in the dishes.
The Seasonal thing has to do with the tilting of the earth's axis.
All of the satellites are directly above the equator, and as the globe
and the northern hemisphere tilts down into summer, there is a 10-15 day
period where once a day for 30 minutes or so, the satellite is directly
between the land-based dishes and the sun. As the earth tilts more, the
sun goes above the dish's reception area, and no more interference. (
until fall when the earth tilts back up again )
If the Knology satellite is directly south of Huntsville, the thirty
minute outage will occur between noon and 1PM. If the satellite is to
our west, the outage will be later in the day.
But.... it will always occur at the same time every day + - 10 minutes.
It can't happen at night, or early in the morning.
( no sun ... no interference )
Sunspots occur on a 11 year cycle, and we are going down the backside
of the 1999-2000 peak. And as you said, Sun spots can enhance some
paths of communications, or cause problems with others.
But again, sunspots only affect the USA if the sun is overhead in the
USA.... not at night.
Don Roden
Googolplex
Put it this way. If there is a chronic problem from sun spots, and the
cable company gets a rash of complaints for it, then they should take
the money you are paying them and use it to install more repeaters and
better shielded cable.
This is like going into a restauraunt and getting cold food put in
front of you and the waiter says, "Sorry, the food is cold because our
oven doesn't work so good--so its not our fault".
Also, I question the sun spot excuse, anyway.
Sun spots do increase electromagnetic (EM) interference. Its mainly
from the collision of charged solar particles with the ionosphere, and
mainly around the poles because the Earth's magnetic field channels
the solar wind there. A very slight amount of EM comes directly from
the sun, but its negligible. I also doubt any pattern seen by the
cable company is related to sun spots. That "April and October"
statement is bogus. The quantity and location of the hot spot is
slightly related to the angle of the Earth relative to the sun, but it
never moves very far from the poles and pretty much never gets very
near Alabama. Also, the EM from the hot spot doesn't propogate well to
other areas of the Earth because of the frequencies in this context.
It would take some pretty hefty solar activity to make a difference in
your cable signal (the kind of solar activity that would make headline
news).
Sounds like a bad cable connection, bad repeater/splitter, or just a
length of cable that's too long without a repeater.
Bob Wilson (Holly's toy)
The usual problem is when the sun passes behind the satellite. It is
more common with small dish units. However, the sun passes on within a
few minutes and the effect occurs during daylight hours.
Bob Wilson