Intermittent Signal Lock - Is there a transmission problem with ABS-2? (Solved- Obscure Line of Sight)

#1

Since 3 days I’m getting intermittent signal lock for ORxPi. First I checked the connector at the tuner end and thought it is because of the loose connection. To verify that I connectd it with the Lighthouse. Lighthouse also reported the same intermittent signal lock issue. Also both ORxPi and LH repoted very low bit rate, sometimes 3kbps and never reached to more than 80kbps. Probably it should be about 90kbps.

Then I checked the connector end at LNB and found no issue with it. Also checked the alignments and everything was fine. Also I cut more banana leaves to clear the line of sight.

But still I’m getting the locking issue. The LED in HDStar tuner blinks about 15-30 times per minute from green to red to green.

So, is there a transmission problem with ABS-2 satellite?.

Pasted image1366×728 64.7 KB

Pasted image1366×728 72.6 KB

Before

WP_20160110_002[1].jpg1456×2592 1.26 MB

After

WP_20160110_004[1].jpg1456×2592 1.22 MB

#2

Is it just me or are those plants in the dish footprint?

#3

I was receiving signal without any issue for the past 3-4 months even with these plants covering the line of sight.

#4

Ah, sounds like that’s not the problem then. Is anybody else experiencing issues, or are you able to test reception of other transponders on the satellite?

I don’t know much about satellite dish pointing, just shooting in the dark.

#5

Thanks Ben, I have a FTA receiver. Tomorrow I will connect it with the dish and see.
Sometimes the LNB is not functioning correctly.

#6

@Ben More than likely, the plants are not in the line of sight. The placement of the LNB out in front of the dish sometimes causes the eye to believe that the field of view is lower from what it actually is. This image probably does a better job of describing what I’m talking about:

#7

I connected the dish with a FTA receiver and test the reception for some other transponders of the satellite both horizontal and vertical. All reported intermittent signal loss.

For all transponders the signal was about 90 but the quality was 0.

I think my LNB is not functioning correctly. I will replace the LNB with a new one and see.

This the siganl/quality for Outernet.

WP_20160111_001[1].jpg2592×1456 940 KB

#8

It could also just be misaligned.

#9

Agreed, that it could just be misaligned.

“Signal” means RF is coming in. “Quality” means digital data is capable of coming in (though the bits can still be empty or all zeroes even with a high quality reading).

Is the skew on your LNB correct? If it’s not, the polarity would be off, and you could be gettting RF but no bits, hence the symptom you’re seeing.

I would recommend double checking the skew on the LNB before replacing it with a new one. (You have to get the skew right when you install the new one anyway, so it’s not even extra work.)

#10

For my location the skew should be -35.1. I adjusted the skew for every degree between the ranges of +10 to -10 but the issue didn’t get solved. I checked the azimuth and elevation also. Everything was correct. Also, I have marked all positions of LNB and elevation with a permanent marker pen at the time it was installed correctly.

EDIT: http://freesatsupport.co.uk/advice-3.html

#11

@Syed, @branko and @barleyguy: Today I brought a new LNB (same brand and model) and replaced with the existing one. Unfortunately I got same intermittent signal lock. TV pictures were coming and going. HDStar signal lock LED was blinking red to green to red.

Actually now the issue should be probably with one of the banana leaf or the coconut tree and breadfruit tree marked with the blue circle. So this weekend I’m going to mount the dish in a new location. I think that will probably solve the issue.

However I can use the new LNB with a separate dish and connect it with my LH. :smile:

EDIT: I just figured out that during the wind condition the loosing frequency of the signal lock is high.

#12

Is the dish mount secure? If it’s not, you’ll get such behavior.

#13

Yes, secured with concrete.

#14

Hey, my ORxPi receiver is back to normal. Now I can get the signal lock. I cut some banana leaves and now the dish antenna has clear line of sight.