Some LNBs tests

RimaNTSS

RimaNTSS

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My Satellite Setup
Some SAT-related hardware.
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N-E from Riga
Hi! Did not find proper place to post, decided to create new tread (can become a short one).
Installed Fibo120 last weekend. As I have 3 LNBs adopted to Fibo feedhorn, made small test to compare them. LNBs are Invacom single, Black Ultra and Octagon Twin. Tuned antenna to 7*E and scanned all frequencies using each LNB. Results put in Excel spreadsheet. By seeing data made a conclusion that BU is winner in this competition. However Invacom showed little bit better results at high frequencies.
Took total sum of percents each LNB showed 2001-2005-1935.
So, in my case BU is better will use it for future, till I get something better.
Right side of the table shows which LNB got better results.
 

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Pretty close results. Which Invacom single is this? Which Black Ultra did you test (single/twin/quad)?
 
Invacom is UniSingle SNF-031, and Black Ultra is Single.
 

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Continued today. And now I am puzzled. :eek:
Two days ago my conclusion was: BU adopted to original FIBO feedhorn (#1 on attached picture) is best solution. But something I did not like there- at frequencies starting at ~12500 performance of this LNB on Fibo120 was not so good.
I took 0,8*W today as my testing satellite and scanned all 76 frequencies with Fibo120 LNB #1 and got results in column F. Again, after 12500 results were not so good. Then I scanned same satellite with BU installed on T90 dish. Results (column H) of course not so great but at high frequencies numbers were better. I thought, maybe LNB # 1 (BU with Fibo feedhorn) is bad.
Then I replaced BU by SHARP LNB (# 4) on T90 and scanned again, and even SHARP outperformed BU on Fibo120!
Then I replaced Fibo feedhorn by holder for universal LNB and put there 2 different Black Ultras (one is quiet old and another one is only 2-3 month old). I also tested LNB #2 which is custom-made out of IBU and has opening angle of 70*.
All results are in spreadsheet. And I see that all LNBs placed on Fibo120 perform not so well on high frequencies.
BU in columns H and N is the same LNB but performs differently.
So, I am puzzled and need some explanation.
But, by now, my another conclusion: BU out of shelf (without Fibo feedhorn) works more or less same as any other LNB on original Fibo feedhorn.
 

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Very interesting. I haven't noticed poor high frequency performance on the Fibo but I haven't looked. Will take a look tomorrow to see if I experience the same phenomenon.
 
The original advertorials years ago for the Fibo did say they were flat across the band and were suitable for rebroadcast use.

It is possibly down to the centre frequency of the LNB dipole (which is always a compromise) as much as the chain of electronics inside the LNB.
 
I've measured 4,8*E spectrum of frequencies and situation is about the same: IBU attached to original Fibo feedhorn showed better results than Inverto Multiconnect (IM) Quad on T90. At very high frequencies IM outperformed IBU. Then I drunk some whisky and started to think maybe something wrong elsewhere not in Fibo! Basically I measured all signals with one receiver, but with different tuners. GB-Quad has A and B tuners. Tuner A, via some cascaded Diseqcs is connected to T90 dish, and Tuner B via positioner direcely to Fibo's LNB. So, I've measured everything with different tuners, and maybe one of them has some problem! That could be the reason! Will check this theory tomorrow.
 

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I added my results to your test from 1-may , just finished it , did not compaire yet .
Must be social on the couch downstairs (saturday evening ) , you know)
 

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Trust! Thanks for spending time and collecting your data. I see you do not have any problems at high frequencies. In that case, I hope, problem is in my receiver, namely Tuner B. Will check it tomorrow, today I am busy - watching Snooker :-Axechase
 
Morning! There is no problems with Fibo antenna. Issue of high frequencies lays in my receiver and, if be more precise, in Tuner B.
I've connected Fibo to Tuner A and scanned Astra 4 @ 4,8*E (green columns). Today weather is just great, therefore numbers overall are slightly better. On high frequencies data is OK now. Also added by hand (automatically it did not want to lock) 12697H 5627 where is Magtisat provider located. There are also several other frequencies higher than 12700, for example 12725V (screenshot attached) which are not easy lockable.
 

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RimaNTSS - can you say a little bit more about custom-made IBU that has opening angle of 70*? I've heard about that mod that should be made in Russia.

Humaxboy
 
RimaNTSS said:
Morning! There is no problems with Fibo antenna.
Click to expand...


Unless it is dented, the only problem you should have is forgetting to clean the secondary reflector. :)
 
Before installation I gave dish and sub-reflector good bath (do not tell my wife I used her expensive shampoo :oops:) Dish is in good shape, no dents. And problem was certainly in tuner B of the receiver, I swapped it to tuner A and it is fine now.
 

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Like bathing a baby. :)


That reminds me, I must clean my LNB caps at the weekend, they are always very dirty after the wind storms of winter.
 
RimaNTSS said:
I've got several of them, but did not made any serious comparison tests. Maybe some day.
Click to expand...

I would really appreciate if you took some time and do the comparison test between them :)
 
Most likely different LNBs will perform in some other manner on different antennas. For example, if my LNB #1 will work better than LNB#2 on gregorian antenna, could happen that exactly same LNBs show completely different results on your antenna. Also can happen that LNB#1 works better on lower frequencies. What I am trying to say: to make complete tests not only LNBs should be changed but also antennas.

Add: Biggest difference in system performance is coming from antenna's size (maybe 90%), rest (LNB, cable, receiver's sensitivity, connectors etc.) is not so influential.
Add#2: Will do some tests soon anyway and, of course, post results here.
 
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