Newsgroup: it.hobby.satellite-tv
Titolo: DSS Transponders, what gives?

I have recently bought and installed a Sony DSS system. I have a signal
strength og 78 on the default transponder #2, when I switch to Transponder
#7 I get a signal strength of 90. What is the deal with this? Is it
actually 90 or is that misleading. Also are we supposed to change that or
not? Also, when I shut off the receiver and turn it back on, it goes back
to transponder #2.


You will find that all even numbered DSS transponders have lower signal
levels than the odd numbered ones.  DSS uses two satellites running
240 watts per transponder to drive the 16 odd numbered transponders.
The 16 even ones are serviced by a single satellite using 120 watts
per transponder.
Each DSS channel is compressed with several other channels on a specific
transponder.  The IRD determines which transponder is needed for a
particular channel.  You can chose any transponder when aiming the dish.
--
Michael Weber
m...@fast.net

Actually, I never had this problem until recently.
I have noticed that the transponders are completely different. I get a
signal of 89% on the odd ones and only 45% on the even ones. Are the
satellites located a little off from one another where a tree could be
blocking some of one and not any of the other?

Wil Adams (
wil_...@geocities.com
) wrote:
: I have noticed that the transponders are completely different. I get a
: signal of 89% on the odd ones and only 45% on the even ones. Are the
: satellites located a little off from one another where a tree could be
: blocking some of one and not any of the other?
First thing I'd do is make sure your dish is aimed properly.
Other than that, my best guess is that your LNB is defective.  This is 
something I'd direct to the tech support people at the receiver's mfr.

 blocking some of one and not any of the other?
The three satellites are clustered around 101 degrees west longitude.
According to the SatcoDX satellite charts (
http://www.satcodx.com
) the
exact locations are:
	DBS 1	101.2
	DBS 2	100.8
	DBS 3	101.0
There is a 0.4 degree variation and it shouldn't have much of an effect
on the aiming of the dish for either set of transponders.
--
Michael Weber
m...@fast.net

...


Hi John,
 The receiver automatically defaults to Transponder #2. You receive from
all the transponders and you do not have any control over which you want.
The signal strength is controlled by the transmitter on the ground and they
increase or decrease to maintain a  reasonable signal back from that
transponder. So Don't worry about the signal differences unless al of them
get extremely low and then it's time to realign your dish.
John in Sacramento


 something I'd direct to the tech support people at the receiver's mfr.
Boy, are you guys off on this one.  It is normal to show different
signal strengths on different transponders for two reasons:
1)  Different transponders are at different frequencies
2)  Different transponders are on different satellites
Both of these factors will affect signal reception strength.  However,
the real conclusions are as follows:
1) The readings for signal strength are relative, not absolute.  A
reading of 97 doesn't mean you are receiving 97% of the maximum signal
strength.
2) This is a digital system.  As such, it will either work or not work. 
As long as the singnal strength on all transponders is above 70 (appx.),
the system will work fine.  There will be no difference in audio or
video quality with a signal strength of 75 as opposed to 95.
3)  The only advantage a greater signal strength has is when it comes to
"rain fade".  A higher signal strength will be able to withstand a
heavier rainfall.  Even if clear signal strengths are around 75-80, rain
fade is rarely a problem for the DSS system.
Dave.

 to transponder #2.
Signal strength will vary from transponder to transpoder with the odd ones
tending to be a bit stronger than the even. Different sets of channels are
broadcast on different transponders. Consequently, whatever channel you
were watching when you shut down the receiver, that corresponding
transponder will be the one that comes up when you turn the receiver back
on. 
That's how it works on my Panasonic anyway.

 
-- 
Mike Martin
P. O. Box 1424
Columbia, MO 65205
mma...@digmo.org