Turksat 4A Ka Band A now active

[deeptho]

Now this is strange: suddenly today most or all of these weird peaks in the spectrum of my Ka LNB have disappeared and I
get a decent spectrum. Literally nothing has changed, except that the dish has moved a few times.


Also, the last couple of days I have been continuously using another LNB which means that two switches through which also the
Ka signal would pass and a positioner have been receiving power. However, that is unlikely to play any role as I had the bad spectrum
also on a completely different dish.

I have had many lnbs breaking down over the years, but one that repairs itself?

 

[deeptho]

I think the problem is somehow temperature related. This morning I got the following spectrum, which does not
look too bad, except that it has a strange flat region it.
I then left the LNB tuned for 10 minutes. After that, I took another spectrum scan and the flat area has gone. One or two
very high peaks are probably still not real, but the spectrum looks pretty OK

This evening I found a similar result: first a flat area in the spectrum. After warming up, a smooth spectrum.
The 2nd spectrum is more as it should be, but note that in the formerly flat area, the spectrum still has a large peak
that does not look quite right. I think the flat area is what happens in the extreme case. After warming, it turns into a less
extreme case and after warming some more it gradually goes to normal.

Either this is related to some electronic components (like electrolytic capacitors, but would there be any of that type inside)
or perhaps it is some moisture problem, e.g., some condensation that evaporates after heating.

 

[deeptho]

Since my last report, I have not managed to produce a clean spectrum. However, I performed a "wet cloth over LNB test". The attached picture shows the before (with wet cloth - blue) and after (without wet cloth -orange), confirming that all the
spurious peaks remain.

I also managed to slightly align the feed and squeeze more SNR out of the 2 muxes
I can receive. It is strange, because I thought I had optimised this already as well as I could and also now it is raining,
which should negatively affect the signals. On the other hand, the LNB is poorly attached right now, and can easily shift.
So I will need to improve this.

 

[dreamsat]

my current scan

 

[dreamsat]

18773 L is switched off

 

[dreamsat]

19931 R 1000 DVBS2/32APSK 3/4 Data

 

[dreamsat]

Data carrier now on 18961 R 1000 SVBS2/QPSK 1/4

 

[dreamsat]

only three transponders can be received

 

[dreamsat]

little update