OTHER Signal Strength Weaker at Night

[TheBUDGuy]

About one week ago, I replaced my old Avenger LNB with an Avenger Universal LNB with dual outputs. Ever since then, however, my signal strength has been noticeably weaker and sporadic.

I have a GEOSATpro 1.2m dish parked on 125W for the PBS feeds. Before I replaced the LNB, these were the Q readings I was getting with a MicroHD during the evening:

•11916 V: 74%
•12145 H: 72%
•12155 H: 67%-72%
•12163 H: 72%
•12169 H: 72%
•12180 V: 85%

The day I replaced the LNB, everything seemed to come in fine; later that night, however, the Q went down sharply for all transponders. Since then, during the day, the H transponders vary in Q and are very sporadic, meaning the Q is not constant: The V transponders also vary a bit, but not as much as the H transponders. The Q also decreases sharply at night. Here are the current readings:

•11916 V: 18%-30%
•12145 H: 0%-21%
•12155 H: 0%-9%
•12163 H: 0%-18%
•12169 H: 0%-23%
•12180 V: 78%-84%

What in the world has caused the Q to go down so sharply? Everything was fine before I replaced the LNB, could that be it? Maybe bad cables?

 

[etlam34]

In my experience, i find that lnbs with multiple ouputs tend to bring in less signal. Have you tried the geosatpro lnb’s?

 

[TheBUDGuy]

No, but I do plan to buy one soon. This one is a cheap Avenger LNB, like the last one, but at least the last one worked. I’ve had that one since 2016. Unless it rains, I’ll go outside and replace the LNB with the old one and see if that helps.

 

[Titanium]

Did you perform a new blind scan after installing? The LO frequency may be slightly off.

Could the LNBF be defective and have excessive thermal drift? Compare the blind scan transponder frequencies taken in the heat of the day vs cold at night.

 

[TheBUDGuy]

Did you perform a new blind scan after installing? The LO frequency may be slightly off.

Could the LNBF be defective and have excessive thermal drift? Compare the blind scan transponder frequencies taken in the heat of the day vs cold at night.

I should’ve listed both but forgot. I did a blind scan during the day yesterday and one just now. They’re below.

•11916 V: Day - 56%-67% Night - 0%-14%
•12145 H: Day - 42%-70% Night - 0%
•12155 H: Day - 14%-45% Night: 0%
•12163 H: Day -09%-56% Night: 0%
•12169 H: Day - 39%-63% Night: 0%
•12180 V: Day - 85% Night: 74%-79%

Even during the day, except for 12180 V, those are not normal readings for the rest. The H transponders used to be 70%-72% and 11916 V used to be 74%.

It’s a gradual curve. As the sun goes up, the signal increases. As the sun goes down, the signal gets weaker. I’ve been trying to figure this problem out for the last week.

 

[spongella]

Very interesting problem. Be interesting to see what the culprit is, As for dual output LNBs, I've always used them (all universal types) with no problems. Seems to point to that new LNB as being the factor. Please keep us in the loop, thanks.

Here a loony suggestion- use a hair dryer at night on the new LNB to see if signal improves. The technique of heating/cooling electronic parts is a basic technique when troubleshooting so maybe not so loony.

Remember you heard it first here on satelliteguys. Nobel prize on the horizon....

 

[TheBUDGuy]

I replaced the new LNB with the old one, but won't be able to get a good reading until after the rain stops. It seems, however, that the Q did not change when I replaced it. Shortly before the rain, 12180 V was 83%-85% Q and 12155 H was 43%-51%Q, which seemed the same as the last week. All other H transponders were 17%-38% Q.

12155 H (HD05) is uplinked from New Mexico around this time every weekday, and I could usually receive it at 74% Q. Now, the highest I've seen it is 56% Q.

Like I said before, everything was fine until later that night. The day I replaced the LNB (last Wednesday, I believe,) everything seemed to be coming in fine. All H transponders were the normal 65%-71% Q. Later that night at around 10pm, however, everything changed. All H transponders went from 65%-71% Q to 15%-30% Q. Since that night, I have not been able to get the H transponders back to those levels.

Maybe this streak of cold weather has something to do with it. It's currently 48F here and it's supposed to be in the 50s for the next few days. But if that were the case, wouldn't the signal gradually decrease instead of suddenly in one day?

Maybe the cable is part or the problem too? But if that were the case, wouldn't; all signals be affected severely? I just don't know the cause of the problem, and it's a shame because I can no longer watch the H transponders without an occasional blip in quality. Even light winds seem to make me lose signal on the H transponders.

 

[FTA4PA]

I replaced the new LNB with the old one, but won't be able to get a good reading until after the rain stops. It seems, however, that the Q did not change when I replaced it. Shortly before the rain, 12180 V was 83%-85% Q and 12155 H was 43%-51%Q, which seemed the same as the last week. All other H transponders were 17%-38% Q.

12155 H (HD05) is uplinked from New Mexico around this time every weekday, and I could usually receive it at 74% Q. Now, the highest I've seen it is 56% Q.

Like I said before, everything was fine until later that night. The day I replaced the LNB (last Wednesday, I believe,) everything seemed to be coming in fine. All H transponders were the normal 65%-71% Q. Later that night at around 10pm, however, everything changed. All H transponders went from 65%-71% Q to 15%-30% Q. Since that night, I have not been able to get the H transponders back to those levels.

Maybe this streak of cold weather has something to do with it. It's currently 48F here and it's supposed to be in the 50s for the next few days. But if that were the case, wouldn't the signal gradually decrease instead of suddenly in one day?

Any chance the dish got bumped ever so slightly out of alignment when you replaced the lnbf? You could try putting gentle pressure on the edge of the dish in different directions to see if signal improves.

 

[TheBUDGuy]

Any chance the dish got bumped ever so slightly out of alignment when you replaced the lnbf? You could try putting gentle pressure on the edge of the dish in different directions to see if signal improves.

No chance. I have adjusted the dish every day for the last week with no change in results. At first, I thought that was what happened, so I went out the next day and adjusted it, and everything came back fine, but not as strong as they used to be. Since then, I've been having trouble receiving them.

At night, the signals used to get stronger; now, it's the opposite.

 

[FTA4PA]

No chance. I have adjusted the dish every day for the last week with no change in results. At first, I thought that was what happened, so I went out the next day and adjusted it, and everything came back fine, but not as strong as they used to be. Since then, I've been having trouble receiving them.

At night, the signals used to get stronger; now, it's the opposite.

That's are real head scratcher, especially since you tried putting the old lnbf back and it didn't fix things. I hope you can figure it out.

 

[cyberham]

FWIW, I've been monitoring 125W closely over the last several days since I just installed a 1.2m fixed dish. Reception has varied greatly, I think due to strong rain storms in eastern US and locally in Atlantic Canada. I tried tweaking my dish but realized that was a mistake. It was already peaked on PBS. I put it back and decided I'm at the mercy of the weather gods. I proved to myself you can't assume that a sunny clear day locally will mean good reception of this satellite here. It seems to also depend on weather at the uplink end.

Sent from my SM-G950W using the SatelliteGuys app!

 

[Keith Brannen]

Doesn't sound like it is the LNBs, so I'd check the coax, replace the connector, or bypass the coax with another one, if possible. Take your receiver out to the dish, etc. to check signal levels at the source, if you can.

I recall having a strange problem once where the signals on three transponders were fine, but over the course of a few minutes gradually lost signal quality completely. Four other transponders did not have the loss (my notes don't say whether they were H vs V, but I believe I would have checked and noted that obvious of a problem). Detached and re-attached coax (cleaned the inside of the coax connectors with a Q-tip) both at the LNB and at the switches, and made a swap of ports on a 22KHz switch, and the problem disappeared (and didn't show up on the swapped LNB port). Might have been a stray strand of the ground, or something was slightly loose enough to cause partial degradation of signal, but definitely weird!

 

[Arion]

No chance. I have adjusted the dish every day for the last week with no change in results. At first, I thought that was what happened, so I went out the next day and adjusted it, and everything came back fine, but not as strong as they used to be. Since then, I've been having trouble receiving them.

At night, the signals used to get stronger; now, it's the opposite.

You might be catching the satellite off of a side lobe. If your really aimed at it with a decent LNB your numbers shouldn't be anything like that.

 

[TheBUDGuy]

I’ll have to check my aim the next warm day we have. Tomorrow is supposed to be 62F, so maybe I’ll check then. I did another blind scan, and as expected, all are strong as of 5:00pm ET. They won’t be like that for long. Here are my readings:

•11916 V: 35%-51%
•12145 H: 63%-70%
•12155 H: 42%-53%
•12163 H: 53%-67%
•12169 H: 53%-63%
•12180 V: 85%

Just for example, let’s say my aim is off and I am receiving these signals off a side lobe. Would I still be receiving 12180 V at 85% Q during the day if that were the case?

 

[TheBUDGuy]

UPDATE 6:28pm ET: I just finished spending about 20 minutes doing some fine adjusting. I believe that I possibly fixed the issue. I’m not sure what I did except move the dish a bit and straighten it (it was a bit lopsided). The Q readings seem to be back to how they were before last week. Here are the Q readings (5 second intervals; I’ll only focus on the H transponders and 12180 V):

12145 H:
63%-65%-67%-67%-63%-70%-65%-58%-70%-67%
12155 H:
49%-37%-46%-46%-58%-53%-49%-51%-51%-46%
12163 H:
60%-58%-60%-51%-58%-56%-58%-65%-63%-58%
12169 H:
60%-65%-63%-65%-60%-56%-58%-63%-56%-65%
12180 V:
85%… … 85%

These readings are similar to what they were before last week, so I have reason to believe whatever the problems was had been fixed. However, I’ll have to wait until tonight to find out if that’s true or not.

 

[Brct203]

my experience with AMC21 is that if I peak the dish using 12180V, I lose Montana PBS and the horizontal TPs. But I gain KBS World from 123W... and if I peak Montana PBS, I lose KBS (as expected), and i still get 12180V but not at its best. If I remember correctly, 127W also has a transponder around 12180V but 123W does not...

 

[TheBUDGuy]

my experience with AMC21 is that if I peak the dish using 12180V, I lose Montana PBS and the horizontal TPs. But I gain KBS World from 123W... and if I peak Montana PBS, I lose KBS (as expected), and i still get 12180V but not at its best. If I remember correctly, 127W also has a transponder around 12180V but 123W does not...

Before I upgraded to a 1.2m in April, I had a 32" dish that I used for multiple satellites, mainly 87W, 103W, and 125W. I’ve has it since 2016. I could easily move it since it was so small, but I can’t do that with the 1.2m, though I kept the small dish on 125W 99% of the time. I could only receive 12180 V (PBS mux) reliably with that dish, but only at 73% Q. 11916 V (Montana PBS) would come in once every few weeks, but only at 9% Q; the rest of the time I couldn’t lock it. I could not receive any of the H transponders. I, too, received interfierece from 123W and received KBS at 56% Q.

 

[spongella]

Wonder if satellite dishes can warp slightly and reform depending on temperature and sunlight?

 

[TheBUDGuy]

I did some careful examination yesterday. The problem is still persisting. I checked LNBs (I have 3 total,) cables, and the dish itself. I ruled out all 3 because: (1) I used a new LNB, (2) the cables had no kinks or breaks, and (3) the dish is not warped. I even moved the dish around because I thought it might’ve been pointed wrong. I spent a few minutes doing that with no change; I ended up back in the same spot it was originally in. I then took a tape measure and measured a straight line from the dish outward to see if anything was blocking the line of view… then I noticed something.

We have a tree here that I never paid attention to. In April, when I put this dish up, there were no leaves on the branches and the branches seemed to be shorter. Now, the tree is in full bloom. Every branch has leaves, and they’re thick.

That right there might be the reason why my signal is low on the H transponders. That line I measured with a tape measure passed right through a few of those branches. Looks like the next clear day, I’ll have to do some cutting. I’ll keep you all updated.

 

[Keith Brannen]

I would think that the tree would be a problem all the time, and not just at night. However, it might be a future problem, so best to deal with it now!

I don't think you have necessarily eliminated the coax as the problem, sometimes it is not obvious by visual inspection.

The best way to check the coax is when the signals are dying in the house at night, then take the receiver and a small TV out to the dish and with a short length of coax check the signals at the source. Or run a temporary new cable from the LNB to the house and straight into the receiver (if you have any switches in your run, bypass them).

Other than that, what is your overall set-up? Do you have other dishes and any switches? What receiver are you using? How long are your coax runs to the house? The more information we have, the better chance we have of possibly pointing to an area where the problem may lie. Photos of the dish and LNB might also help.