dish 101 question

timok1

New Member
Oct 23, 2012
2
0
Dickson.ok
howdy all. We've got a dish 500 with a 722 and an extra unit for bed room. I'm sure this is a simple question for you guys. How does a single coax carry both input signal from sat dish and output signal to tv2? I've seen the phrase back feed used but it doesn't make sense to me. It seems defy common sense. Thanks in advance Tim from the rocking tjc
 

KC9TIK

SatelliteGuys Family
Oct 23, 2012
91
1
Angola, IN
It uses a complex system of bandpass filters, called a diplexer, to separate the frequency bands. The satellite signal and the TV signal uses two separate bands, and therefore can use the same cable.
 

3HaloODST

SatelliteGuys Master
Pub Member / Supporter
Jul 2, 2010
6,648
97
Earth
They accomplish this by using diplexers. They work because the sat signal and the TV2 UHF signal use different frequencies. They work by combining the signals on the single coax and splitting the signals back as if they're separate cables. Think if it like road lanes. The different frequencies are like different lanes on the road :) .

Sent from my iPhone 4S using SatelliteGuys
 

timok1

New Member
Oct 23, 2012
2
0
Dickson.ok
Ok thanks . So the splitter looking gismos are diplexers. Guess that's why they have more than just in and 2 outs. And now you know why I operate a dozer and not install sat equipment. Very well explained to a sat challenged individual. Now if someone can get digital tv to work like anilog used to, I 'd be a happy camper. cheers ,beverage of your choice to all. Tim from the rocking tjc
 

3HaloODST

SatelliteGuys Master
Pub Member / Supporter
Jul 2, 2010
6,648
97
Earth
Here are some simple diagrams of how the diplexer + separator and the triplexer work and are commonly used. Note that the triplexer is just a combination separator/diplexer all-in-one :-


filestream.ashx.jpg __filestream.ashx2.jpg
Diplexer | Triplexer

The same goes for the other end of the

(Diagrams are from mydish.com)

There are diplexers on each end of the single coax line, as shown in the following simplified diagram :-
 

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boba

SatelliteGuys Master
Dec 12, 2003
11,350
1,035
Dorchester, TX.
Ok thanks . So the splitter looking gismos are diplexers. Guess that's why they have more than just in and 2 outs. And now you know why I operate a dozer and not install sat equipment. Very well explained to a sat challenged individual. Now if someone can get digital tv to work like anilog used to, I 'd be a happy camper. cheers ,beverage of your choice to all. Tim from the rocking tjc
I think digital OTA is better with some limitations. Scroll down the page Satellite guys has a forum hidden near the bottom that offers help with OTA.
 

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