trying to understand rain fade

shelly

SatelliteGuys Pro
Original poster
Sep 19, 2003
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A month ago, a steady drizzle (.01" accumulation) dropped my signal 40 points and I lost all reception with my 18" dish. It was evening time.

Yesterday we had a similar "rain" only the drops were larger. My quality only dropped from 96 to 95 and the strength only dropped from 95 to 92. S/N dropped from 15.xx to 14.xx. I was surprised that I never lost the signal. It was daytime.

Last evening, with heavily clouded skies but no rain, my quality was 82 and strength was 85. S/N was 11.xx and it is usually 15.xx. Picture as usual.

Why didn't I did lose signal yesterday? Does daytime vx. nighttime figure into this?

Shelly
 
shelly said:
A month ago, a steady drizzle (.01" accumulation) dropped my signal 40 points and I lost all reception with my 18" dish. It was evening time.

Yesterday we had a similar "rain" only the drops were larger. My quality only dropped from 96 to 95 and the strength only dropped from 95 to 92. S/N dropped from 15.xx to 14.xx. I was surprised that I never lost the signal. It was daytime.

Last evening, with heavily clouded skies but no rain, my quality was 82 and strength was 85. S/N was 11.xx and it is usually 15.xx. Picture as usual.

Why didn't I did lose signal yesterday? Does daytime vx. nighttime figure into this?

Shelly


Maybe the last time it drizzled, and you lost signal was because there were more clouds, and rain to the east of you in front of the signal your 18" dish is trying to recieve? This time maybe the clouds were moving more south, or north? I don't know but it may play a factor into it all. BTW, I had a very light rain last night and my signal fell to 95 from 99, and power from 89 to 85. So far so good on the 30" dish.
 
DarrellP said:
Certain size of raindrops absorb the signal more than others.
(sharpshooting ON)
The rain drops scatter the signal.
(sharpshooting OFF)

I'm sure that there are a whole gambit of things that can effect the signal. I would think Jay is right in the rain in combination with the cloud cover and winds are what determines the "rain fade" more then anything else.
 
A few nights ago I had a very light rain and totally lost everything for about an hour. It's rained harder before and I still had my signal. Seems drizzle is worse on a signal than hard rain.
 
Same thing here. That makes sense though. There are more drops doing the scattering.
How about snow? I haven't owned any type of satellite in the winter yet. Does snow fall affect the signal as well? The snowfalling not accumulation on the dish.
 
Well they should make mesh dishes like they do for C band so rain and snow go through the dish and rain fade is not much of an issue.

Bill
 
Well, remember that rain fade is not necessarily a phenomenon that occurs right in front of your dish. There could be a storm happening from miles away and if you are on the edge of the storm and all you see is a drizzle, you might never see the what causes your signal to drop.
 
dledeaux said:
Well, remember that rain fade is not necessarily a phenomenon that occurs right in front of your dish. There could be a storm happening from miles away and if you are on the edge of the storm and all you see is a drizzle, you might never see the what causes your signal to drop.
Good point. That is especially true here in the West Coast since the inclination angle is only ~11 degrees.
 
Since my initial install in November, I had three major outages lasting from several hours to as long as three days. In all three cases I could attribute this to ice or freezing rain...

Does anyone know if they make 18" dish with a defroster?
 
Ilya said:
Since my initial install in November, I had three major outages lasting from several hours to as long as three days. In all three cases I could attribute this to ice or freezing rain...

Does anyone know if they make 18" dish with a defroster?
You can try putting melting salt on top of it :D
 
Walter L. said:
You can try putting melting salt on top of it :D
Good idea! :yes

Seriously, my dish is too high on the roof. I can't easily get there. A simple defroster (like those on the rear window of the car) would do the trick, I think...
 
Hey Darrell - seriously - did you get any signal problem with the rain last night (~ 8 PM). My signal went down from 90-94 (normal) to 65-70 and I lost the signal. I never have problem before with rain.
 
If the dish was made with mesh it would have to be slightly bigger, like the BSKYB dish in the UK! I always try to keep the dish as low as it can go, check my web site for some low dish install pics, but alas sometimes we have no choice but to put it on the roof, but even then the lowest part of the roof, also some customers want it WAY up there above the top of the roof!!!!! They are very happy, until they call saying " I lost my picture, can you come out and climb up there and clear the snow? I have a big rope I can tie round your waste, there is only 3-4 feet of snow up there" (True Story)
 
Walter, I watched Dish last night since the pj I borrowed from work only has a VGA and S-Video connector, I opted to watch Cold Case & a bit of Along Came A Spider then went to bed. I did lose my signal during rain within the last few days, I am seriously considering going to a 30" since once I dump Dish, I'll be up a creek during Winter. My signal was wavering around 49 when it dropped out, using a 24" dish.

Thinking back about last night, I was monitoring Voom on my 13" Commodore monitor and I never had a loss of signal, though it may have been raining more up where you are.
 
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