Rain Faid

[McVey]

I have lost signal for the past 4 hours due to rain. Does directv give you a credit for it??

 

[Beavis]

Not for only 4 hours, no.

 

[herdfan]

4 hours? Unless Noah is around, you have additional issues other than just rain.

I was having a bad rain fade problem where even a little drizzle would cutout the signal. It turned out that the tree my dish is under was would droop when the leaves got wet and block the signal. A good pruning and I haven't had an issue since.

Where are you located?

 

[jpn]

I've actually had moderate improvement using a DishCover with separate LNB cover. It's not perfect, but it helps. Rain tends to run-off the cover faster than the bare dish.

 

[TNGTony]

A 4 hour rain fade event has never happened to me. In the last 8 years with a Dish the longest rain fade event I've ever had was about 15 minutes. I am certain that there is something else going on here. Could be water in the coax or LNB or more likely a tree-branch sagging in the line of sight. Remember the dish is getting signal from 22 degrees above where it appears to point

See ya
Tony

 

[damaged]

I'm wondering what his signal strengths are on a clear day, maybe not enough signal margin.

Regarding the covers, rain fade is caused by storm cells in the atmosphere with a high enough density to cause diffusion of the signal (that's why rain fade starts BEFORE even a drop has hit your dish), it is not caused by rain dripping on your dish (unless its like a waterfall on your dish).

The sprays that claim the help rain fade, are just plain scams/BS, they bead the water and might help the dish last longer (but at 50 bucks for a brand new dish who wants to spend 12 bucks a can for repackaged PAM?)

The spray or covers might help snow sticking, and/or make the rain bead off quicker, but not to the point of affecting rain fade one way or the other.

 

[jpn]

The spray or covers might help snow sticking, and/or make the rain bead off quicker, but not to the point of affecting rain fade one way or the other.

I understand the theory, but I've observed otherwise.

Immediately after upgrading to the Phase III dish, I experienced loss of signal during moderate (not torrential) local rain, and pixellation on HD channels during light local rain. Installing a cover has significantly improved performance during local rain.

I still get rain-fade due to significant storm cells somewhere in my LOS.

 

[damaged]

Thats quite strange, I am on the north edge of a hurricane, and have no such cover with a 3lnb, and the only rain fade I got was 10 minutes before it started raining, once it began raining, the rain fade went away.

After reading your post, I sprayed water with a hose on my dish(lots of water, lots lots), with no cover, and observed the signals for 10 minutes, and the signals never dropped at all, no matter where the hose was sprayed, so how would a cover help?, adding a cover would do nothing, in fact it would probably reduce the signal if anything.

I am not saying your making it up, but it may be a placebo effect, there is just no empirical evidence that proves that the act of falling rain on a dish affects signal, in fact the empirical data gathered from the above mentioned experiment proves the opposite.

Here is a text on rain fade and what it is caused by (and none of them are from rain on the dish/lnb itself, the only documentation you will find that states otherwise, are the scam artists who sell the 'anti-rainfade' spray or covers), the only solution is a better dish, period, saying otherwise is simply denying physics (unless the laws of physics somehow change for you), as a droplet on the face of your dish does not have enough density (even if the dish is covered in droplets, its still to thin) to be a real factor.


http://www.solidsignal.com/satellite/rain_fade_about.asp

Quoted from above:
"Rain rate is the most common factor used to determine rain fade. Rain fade seems to correlate very closely with the volume of raindrops (expressed in cubic wavelengths) along the path of propagation. This is opposed to the common misconception that the degree of attenuation is proportional to the quantity or individual size of the raindrops falling near the receive site."

Me: So the few thousand raindrops collected on a dish cannot be the cause of significant (if any) rain fade since the dish does not have enough area to contain the volume of raindrops required to cause propigation problems.

Covers, by the way, do have their uses, as the poster below states to keep the lnb/dish in good shape, and they can look nice too, but covers reducing rainfade? No.

 

[TNGTony]

I've posted this before, but it is something that most people just do not understand.

Rain fade is a misnomer. It isn't the rain that causes the signal loss per se. It is the miles-thick moisture-laiden clouds that cause the rain fade. In heavy downpours with large rain droplets and relatively thin clouds (only a mile or two thick), most people will not see the effects of rain fade. At the same time, with no rain and a very large storm cloud (10 miles thick) between you and the satellite, most people WILL expedience signal loss.

Personally I experience rain fade 3 minutes or so before the rain arrives because it is the clours to the west that are actually blocking the signal. As the clouds and rain get overhead, the signal I get from the southwest is no longer blocked and I can watch programming just fine during the rain storm.

So, as I mentioned before, a 4 hour rain fade event is indicative of another problem. Either a sagging tree branch, or leaky seals on cables/switches/lnbs.

Dish chovers have quite a few advantages. By keeping water off the LNB itself and the connectors, it prevents excessive wear due to weather. But Dish covers do nothing for signal loss due to "rain fade" no matter what the anecdotal evidence. If the connections were allowing water in the line, it may apear to help rain fade, but in reality it is just doing what a properly fitted connection should have done on its own.

See ya
Tony

 

[damaged]

I think Tony hit the nail on the head, that is why the cover seemed to help, it was preventing water from leaking into a connection. You also mentioned you went to a 3lnb dish(if you also have a cascadable multiswitch (exposed outside) in the mix it's going to make a leak alot more likely), I assume you had a single, if you experienced MORE (what you're calling) rainfade with the 3lnb dish than the single, that should tell you something, since with the triple, rainfade should be LESS by default(bigger dish=less rainfade), so we are left with:

1) the installer didn't peak the dish as well as the single one was.

2) The dish/built-in multiswitch are defective.

3) There is a problem with the triple lnb dish install itself (rain leaking in, bad connectors, etc).

I vote for 3 .

 

[jpn]

I think Tony hit the nail on the head, that is why the cover seemed to help, it was preventing water from leaking into a connection.

I don't think so in this case. Maybe for McVey and the 4-hr event. When I lose signal due to local rain, it usually returns right after the storm passes. A leak would take some time to dry-out.

You also mentioned you went to a 3lnb dish(if you also have a cascadable multiswitch (exposed outside) in the mix it's going to make a leak alot more likely),

I have the standard Phase III dish with integrated multiswitch. My connections are inside the rectangular tube which holds the LNB/switch unit. Water would have to leak into the tube before it got to the connections. The LNB is a snug fit into that tube and can't be misaligned, it's got a snug bolt holding it in place.

I assume you had a single, if you experienced MORE (what you're calling) rainfade with the 3lnb dish than the single, that should tell you something, since with the triple, rainfade should be LESS by default(bigger dish=less rainfade), so we are left with:

1) the installer didn't peak the dish as well as the single one was.

2) The dish/built-in multiswitch are defective.

3) There is a problem with the triple lnb dish install itself (rain leaking in, bad connectors, etc).

I vote for 3 .

You missed a couple of items.

1) The triple-LNB dish views a wider range of sky than the earlier dish. It's a broader focus and that has some effect.

2) Curvature of the earth matters. By Tony's statement of hurricane I'm guessing he's in FL. When I've been to FL, the dishes point almost straight up a the sky. Here near NY, they have a much shallower angle to the southern sky. The earth's curvature is putting a many, many more miles of atmosphere between my dish and the sat. That means when there's a storm coming from the south, I'm looking sideways and upward through it; while he's looking nearly straight-up. In general, the southern US gets a much stronger and more robust signal than northern states.

 

[damaged]

Water can find its way into the darndest places, I doubt a 'rectangular tube' guarantees a water-tight seal.

 

[jpn]

Water can find its way into the darndest places, I doubt a 'rectangular tube' guarantees a water-tight seal.

I never said 'watertight'. I said it's a tight fit. I didn't state my speculation: (a) I think it would take a pressurized flow to make more than droplets penetrate into the gap between the LNB housing and mounting tube; and (b) if a small amount of water is enough to disrupt my signal, then my signal should not return until that water dries; (c) my signal returns immediately after storms pass -- too quickly for water to dry (if that's the cause).

Regarding the part you edited-out: I'm not arguing the science and I understand that the cover should not help. But I'm prone to occasionally throwing money at snake-oil remedies, and figured $30 wasn't going to break the bank if it didn't work. I can't explain it, but the signal has improved during rain and the cover does not mask the gap between LNB housing and mounting tube.

 

[inwo]

A cover can make a modest improvement. I'll explain it this way:

The essentially parallel radiation coming into a dish is reflected in such a way as to cause gain. This gain can be pictured as concentrating the radiation as it approaches the lnb.

Picture one drop of rain and the amount of signal it can block on its way to the dish. This same drop will block the signal twice inside the dish. The signal blocked between the dish and lnb also represents a multiple of the signal coming in, as related to the gain of the dish.

Test it this way. Hold a quarter in front of the dish. Now hold a quarter in front of the lnb.

I'm no proponent of dish covers. They are a waste of money!

 

[4408]

I will say...the triple dishes are slightly worse for signal because they compromise.

if you REALLY want to minimize rain fade, get 3 large aftermarket dishes (at least 20 inches, if not 40, 2 with regular dtv lnb's and 1 with a sat C kit. Rig them all to a multiswitch, and individualy peak all three.

but then, most consumers are more worried about the dish matching their decor than about signal...why else would they want the thing in the center of their roof instead of by the ground source?

 

[jpn]

I will say...the triple dishes are slightly worse for signal because they compromise.

if you REALLY want to minimize rain fade, get 3 large aftermarket dishes (at least 20 inches, if not 40, 2 with regular dtv lnb's and 1 with a sat C kit. Rig them all to a multiswitch, and individualy peak all three.

but then, most consumers are more worried about the dish matching their decor than about signal...why else would they want the thing in the center of their roof instead of by the ground source?

I've considered the multi-dish solution... don't forget: (3) dishes is about to become (5). Starting to get expensive and complex.

As for position, there can be more to it than being close to ground. Trees would block my LOS if my dish was close to the ground source. It's also not close to either end b/c I don't want to be at the edge of the roof if I ever have to do any maintenance (check connections, re-aim, add another cable).

As for aesthetics, you must admit: 5 dishes on the roof looks more like you're afraid of alien invasion (or a military base) than a comfortable home.

 

[damaged]

I figured the 50 bucks for the 3 lnb was worth it, mainly because the installer of the round dish put the multiswitch on the wall, about 12 inches off the ground (here it floods like crazy) so once i found out the multiswitch for the 3lnb was built-in with the dish, it was worth 50 bucks to me NOW rather than paying 30+ bucks for a new switch when it died from exposure, and the icing was my avg signal strengths went up from 84-86 to 94-100, rain fade has been reduced alot. (yes I know it is possible the 1st installer did not peak it well, if that is the case, it was still worth the 50 bucks for a repeak, something which can run 150+ (without the service plan)).