rain fade and dish 500

[DruzeTito]

Hello everyone..

I would like to know how hard does it have to rain for a properly set dish 500 to lose a signal on 119 or 110. Because I have a Circular LNB attached to my KU fortec LNB which is on the focal point on a 90 cm dish and the rain fade is annoying even on drizzle.

[bobkat]

Rain fade is hard to "measure" because it can be local rain or rain near the uplink facility. I have tried to see how much rain it takes to knock out my ExpressVu 20" pan (same as Dish500) and I notice it is difficult. I get good signal in a driving rain but no signal if its just cloudy. So I think your question is hard to answer. If even a slight drizzle knocks out your circular LNB on a 90 cm pan I would say it needs a tweak of alignment.

kat

[DruzeTito]

I tried to align it the best I can but because it is off center from the focal point then there is only so much I can do. There is also the problem with weak and strong transponders. I wish that every transponder was equal.. why are some weak, and some strong? Is the best possible way to do this to adjust the dish using the weakest TP possible, then every other TP will be good right?

[dtsexpert]

Try to move the circular lnbf higher/lower to optimize the signal quality. I get very strong signal for circular on my motorized 90cm dish (circular lnbf tied next to the linear).
For me, rainfade problem only happens when it rains VERY HARD.
Michael

Originally Posted by DruzeTito

I tried to align it the best I can but because it is off center from the focal point then there is only so much I can do. There is also the problem with weak and strong transponders. I wish that every transponder was equal.. why are some weak, and some strong? Is the best possible way to do this to adjust the dish using the weakest TP possible, then every other TP will be good right?

[bobkat]

Here is some info I found somewhere:



---> "What is a Transponder? On the installation screen I've noticed that my transponder number changes.
Some numbers have different signal strength than others. Today transponder 05 I can 99% signal strength. Yet 13 for example has 86%. Why is that?

A transponder is the transmitter/antenna on the satellite. Typically a satellite will have around 32 transponders, although the owner of the satellite may not be licensed for all 32. Each transponder operates at a specific frequency, and can carry from 1 to 8 channels of TV and audio. Even and Odd transponders operate with opposite circular polarization to prevent adjacent "channel" interference. When you go to the installation screen, the transponder shown will be the one carrying the program you were last watching. You can not choose to have your program come across a different transponder. Several of the transponders on some of the satellites are operating at double power, and this accounts for some of the difference you are seeing. Other transponders might have different effective strengths at different geographical locations within their footprint. But there's not much point in being concerned, almost any strength over 50 gives you a perfect picture. Higher strengths just give you some margin against rain and snow fade."

I saw a really detailed explanation of transponder power too. Even more juicy than this one -- I'll see if I can find it...

kat