Forums > Specific Focus > Technical Mexico

Rolly

Jul 23, 2005, 7:11 PM

Post #1 of 12 (3173 views)

Shortcut

Satellite dropout problem

Can't Post | Private Reply

I have a new problem with my DishTV. Sun interference. Of course, there has always been the problem of a few minutes each day when the sun is behind the bird and reception gets wiped out. But my problem is something quite different.

Several channels are being wiped out by sunlight. It has been going on for a couple of months, and it has gotten worse – worse in the sense that the dropout starts earlier and last later in the day. At first it was only a couple of hours in the afternoon. Now the problem starts shortly after sun rise and goes on until shortly before sunset. At night everything works fine. It’s always the same channels that are wiped out. The good ones always work and the bad ones are always bad. The bad ones are on various transponders, so it does not seem to be transponder specific.

I have cleaned the dish of dirt and bird shit. The nearby tree is not getting in the way.

Any ideas? Paint the dish black?

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

sfmacaws

Jul 23, 2005, 9:19 PM

Post #2 of 12 (3159 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

There are charts for different times of the day and year for different sats that tell when sun spots will knock out the signal. I don't have the link and really, this is not sounding like it, I don't think they last that long. It's odd that they are on different transponders too. I wish I had something constructive to say Rolly, that is something I haven't heard of. Can you shade the dish without interfering with the feedhorn? Maybe it's getting too hot, or maybe some of the cabling is getting too hot.

Jonna - Mérida, Yucatán

johanson / Moderator

Jul 23, 2005, 9:45 PM

Post #3 of 12 (3156 views)

Shortcut

Re: [sfmacaws] Satellite dropout problem

Can't Post | Private Reply

Jonna is correct. The only time the sun creates signal problems is when it is directly behind the satellite your satellite dish is pointing at and in your area Rolly that happens for a few minutes per day for several days during both the spring and fall. That does not happen at this time of the year..

Too much heat lowers the efficiency of the LNB, but I don't think it would make too much difference, especially if you have that dish boresited in.

I guess I would experiment around trying to boresite the dish in, you know better point the dish at the satellite and see if that helps I would also see if the LNB is getting too hot. I can remember times when it was real cold at night when the LNB seemed to be stronger than normal

Let us know what happens.

taltman711

Jul 26, 2005, 4:56 PM

Post #4 of 12 (3112 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

Rolly,

Chances are you have a bad LNB or a bad switch. Either can cause the problem you are having. Both can be temp. sensitive. The LNBs', when exposed to the sun(and direct heat) will fail or partially fail. When the direct sun is gone, it very often will seem OK. Most switches are not in the sun. If yours' are, try to relocate out of the weather. They last a lot longer. They also can act as above when going bad. If you can get a new switch locally, change with the one you have. Try to make sure you can exchange for LNB if it makes no difference.

Tim

Rolly

Jul 27, 2005, 7:46 AM

Post #5 of 12 (3088 views)

Shortcut

Re: [taltman711] Satellite dropout problem

Can't Post | Private Reply

Thanks Tim.

What is the switch?

Others have suggested heat as the problem, but I wonder about that. The dropouts begin in the morning long before it gets hot, and service returns in the late afternoon while it is still hot -- the hottest time of day here is often at sunset y which time the channels have returned. Today is overcast and cool, no direct sun, and still the channels are gone.

I have also found that if I tune to a channel early in the morning before the trouble starts, that channel will remain functioning for several hours with increasing breakups on the screen until it finally drops out. But if I tune out, I cannot come back to the channel. This suggests that the receiver is capable of remaining locked on a signal that is too weak to enable an initial lock.

I will look into changing out the LNB. And the switch too after you explain what it is and where I can find it.

I might add that I'm an old broadcaster, but I was a studio guy, and I don't know shit about RF.

Thanks for your help.

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

(This post was edited by Rolly on Jul 27, 2005, 7:49 AM)

johanson / Moderator

Jul 27, 2005, 10:02 AM

Post #6 of 12 (3082 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

Hey, if you only have one dish, you wouldn't have a switch in my area of Mexico. I am assuming that you are using a single Dish pointing at 119 degrees West only, and that you are using a single LNB. (In the states you have one Dish with a double LNB at the focal point that really is pointing at two locations in space)

I use a switch because I have two satellite dishes, one pointed at 110 West and the other pointed at 119 West. You take the coax from each of these satellites and bring them together using a switch (it looks like a splitter in reverse) and then you have one coax leading to your receiver. One way to see whether it is your switch or not would be to eliminate the switch and see whether the signal comes in better on the channel or transponder that's starting to become in weak. (I think the switch is called a SW21)

You have to know though which satellite that weak channel is on and hook up directly to that satellite dish not using the switch. It would be also interesting to know if all of the weak channels are coming from the same satellite If you are pointing at two points in the sky then are the signals being lost coming from one of the two satellites? There are all kinds of things you can do to help you ID what the problem is.

To see what is on 110 W go to http://www.lyngsat.com/...ges/dish110_sid.html
To see what is on 119 W go to http://www.lyngsat.com/...ges/dish119_sid.html

I hope this helps

PS I did it again before I updated the post. Yes the stronger of the two satellites is 119 and that is the one that most point at if they are only pointing at one dish; not 110 as I originally posted

(This post was edited by johanson on Jul 27, 2005, 11:56 AM)

Rolly

Jul 27, 2005, 10:06 AM

Post #7 of 12 (3081 views)

Shortcut

Re: [johanson] Satellite dropout problem

Can't Post | Private Reply

Thanks Pete, that's what I thought about the switch. I have only one dish, and it looks at 119W. So guess it is the preamp.

Thanks

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

(This post was edited by Rolly on Jul 27, 2005, 10:18 AM)

taltman711

Jul 27, 2005, 10:50 AM

Post #8 of 12 (3077 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

Rolly,

Failing LNBs can be very temperature sensitive. Often, when the sun is shining on the LNB and its internal temp. goes up, it will fail just as you said. Increased pixillation and then failure, or, your set top box can't lock. The air temp. may even be cool. Conversely, when the sun angle changes or the LNB gets a little shade, the internal LNB temp. may go down enough to allow it to again function. The air temp. doesn't really matter enough to cause problems. Dish has recently acknowledged that they sold whole bunches of LNBs that have temp. failure problems. Do a search on www.dbstalk.com or www.satelliteguys.us regarding LNB failures. As Pete said, if you only have one dish, and the RG6 from that dish goes directly to your STB, then no switch is present.

Tim

Rolly

Jul 27, 2005, 12:28 PM

Post #9 of 12 (3066 views)

Shortcut

Re: [taltman711] Satellite dropout problem

Can't Post | Private Reply

Thanks Tim. I read some of the posts on the links you gave. No doubt about it, I have a hot one.

Since I live in Mexico and do not "officially" have Dish service, how can I get a new LNB? Radio Shack? A local satellite dealer? Are they all the same or do I need a specific replacement model?

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

(This post was edited by Rolly on Jul 27, 2005, 12:28 PM)

taltman711

Jul 27, 2005, 5:50 PM

Post #10 of 12 (3049 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

Rolly,

All Dish LNBs are NOT the same. Tell me the model # of your box, and I can tell you the correct LNB. Also, how many cables come from your dish?? I am guessing just 1 or possibly 2. You can find the model # on the system info. screen if you are not sure. The newer boxes can handle any Dish LNB, but the older boxes need a legacy LNB, or an adaptor with the newer Dishpro or Dishpro+ LNBs. By the way, have you checked all of your cable connections?? I assumed you had, but if you haven't, make sure all the inside connections are snug, and all of the outside connection are free of moisture. Even a half turn loose can make the connections hypertouchy to any signal change. Moisture in the outside connections will do the same. Yes, RadioShack sells Dish stuff as do any local DishSat. dealers--at least here they do. Just give them the right info., or take the existing LNB to them and they should hook you up with the correct part. Not too expensive--at least here in the USA!

Tim

Rolly

Aug 19, 2005, 11:49 AM

Post #11 of 12 (2985 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

Update: Problem solved...by accident.

To recap -- I was loosing about half of my DishTV channels during the daytime; they were all OK at night. The suggestion was that this was a heat problem -- the preamp was being heated by the sun. I noted that there was a nearby tree that did not seem to be in the beam pattern.

Yesterday, we took out that tree for non-satellite reasons. Wonder of wonders! the missing channels reappeared!

It seems that neither the tree nor the heat alone was enough to cause a problem, but the combination was.

I am now a happy camper again.

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

johanson / Moderator

Aug 19, 2005, 2:34 PM

Post #12 of 12 (2975 views)

Shortcut

Re: [Rolly] Satellite dropout problem

Can't Post | Private Reply

Glad you got your DISH system working.