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Why do some transponders from the same SAT run at different signal strengths? I had 61.5/32 get down to 5-10 (then lost), last night; while others were 40-50 during the same storm. Any technical reason?
 

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Some transponders are at different signal levels to begin with, so they react differently to storms... also, there is technically some degree of physical separation to the transponders and that allows for things like a branch to be in the front of a dish but only block reception to some transponders, or a cloud overhead to block some but not all as it passes by.
 

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HDMe said:
also, there is technically some degree of physical separation to the transponders and that allows for things like a branch to be in the front of a dish but only block reception to some transponders, or a cloud overhead to block some but not all as it passes by.
It isn't "physical separation"; most are coming off the same antenna, and from a single point that's 22,600 miles away. The satellite is roughly the size of a medium UPS truck. Let's call it 10' wide, and assume there are two antennas and that the signals are coming from them; the center point would at most be 20' apart. A 20' spread from 22,600 miles away is such a tiny arc that it is virtually unmeaurable, and certainly nothing that could allow a tree branch to block one but not another. Even with multiple satellites in the same orbit, you're generally talking about .3-.4 degrees extreme spread max.

The things that *are* different are that some TPs are spot beams, so beams aimed at you are stronger. And the individual amplifiers for each TP will be at slightly different power, or even dramaticly different power because most TPs combine 2 or 3 amps together, so if a TP has lost one of it's amps due to failure, that TP will be lower in strength compared to the others. Finally, TPs are spread across a range of frequencies, so it is possible for obstructions (clouds/moisture in the air) to affect certain freqs more than others, but not because they are physically separate.
 
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