Reflective Objects And Satellite TV Reception?

[Lone Gunman]

I've been thinking about this for some time but never took the time to post this question before so here goes.

What I'm wondering about is what effect, if any, does a large reflective type object sitting near a BUD have on satellite TV reception? Reason I ask is I've notice that if I park my 24ft car trailer or the 1 ton Dodge that I tow with in certain areas of my driveway I see some problems receiving some of those "marginal" Ku signals. I'm not talking about parking the stuff directly in front of the dish mind you, but off to the side of line of site within 15/20 ft or so or even in front of it about 30ft away where the dish is actually looking over the top of the trailer.

Can this cause reception problems or am I just barking up the wrong tree?

Thanks

 

[mmewrench]

Anything that can reflect noise, can interfere with a digital signal. Even the ground.

 

[FaT Air]

A few possibilities come to mind. One, already covered by mmewrench, noise.
Another is the desired signal, but a reflection of it off the vehicle, entering the feed out of phase would be a 'destructive' interference.
The other I can think of: A reflection of an adjacent satellites signal 'introducing', well, adjacent satellite interference.
Lastly, a combination of all of the above.

 

[Joe DC]

A few possibilities come to mind. One, already covered by mmewrench, noise.
Another is the desired signal, but a reflection of it off the vehicle, entering the feed out of phase would be a 'destructive' interference.
The other I can think of: A reflection of an adjacent satellites signal 'introducing', well, adjacent satellite interference.
Lastly, a combination of all of the above.

Here is a web page http://www.hdtvprimer.com/antennas/siting.html
describing reinforcing and destructive "layering" as it applies to UHF terrestrial signals. I suppose it would apply to any rf signals if the conditions are right. Experienced this when helping a neighbor put up a UHF TV antenna recently. Actually had to lower the antenna to get a better signal.

 

[updatelee]

if the lnb's scalar ring is visible from the trailer it *might* cause interference. Youd see it right away on a spectrum analyzer as higher noise floor. The angles would have to be just right.

This is another reason imo a spectrum analyzer is king compared to satellite meters, they not only tell you the quality of the signal, but give you an idea of why its good or bad.

UDL

 

[Lone Gunman]

I kinda figured that there was a connection between trailer location and possible reception problems. Actually I have two enclosed car trailers. One 24ft for the dragster and 20ft for the door car so there's probably a lot of reflected stuff around my house. Most of that stuff is in the area of that Unimesh dish as the Winegard is on the other side of the house.

Just another of those things that make you go hummmmmm......................................

Thanks guys.

 

[RT-Cat]

Interesting information about noise and signals bouncing around. Reminds me of a conversation overheard years ago when 4DTV was in its heyday. A person stated he was not going to buy one of those expensive dish things because he just points his TV antenna at his neighbor's dish and picks up everything he wants to see. He was serious. I just walked the other way.....

 

[Lone Gunman]

Interesting information about noise and signals bouncing around. Reminds me of a conversation overheard years ago when 4DTV was in its heyday. A person stated he was not going to buy one of those expensive dish things because he just points his TV antenna at his neighbor's dish and picks up everything he wants to see. He was serious. I just walked the other way.....

This reminds me of a similar deal where a power company guy told a customer that the reason there were two wires going to his house was because they took the power from him then sold it to his neighbor and so on down the street. Someone got in big trouble for that one!

 

[RT-Cat]

That's a good one.