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View Full Version : Benchmarking various LNBs on Channel Master 1.2 with/without feed horn



Franky_D
26-05-2013, 09:59 PM
I decided to perform this test to mainly answer the question if matching feed horn provides any added value on a 1.2 Channel Master dish. Location: Copenhagen, Denmark.

For this matter I compared:
- Invacom SNH-031 (LNBf) vs SNF-031 (flange C120); and
- Inverto Black Pro LNBf 0.2 dB vs Inverto Black flange C120.

Although SNH-031 and SNF-031 should be in principle the same LNB with the exception of the wave guide part, the tested SNH-031 happened to be a bit more successful one – overall approx 5 dB higher gain and lower noise. See attached certificates with test results for these specific LNBs (came in the boxes with them).

In addition few more LNBs were put to test, including few professional ones.

I used two different satellites for benchmarking to have more objective results:
- 36E (Eutelsat 4W and Eutelsat 7W);
- 28.2E (Astra 2F and 1N).

Just to make it more interesting I was testing both linear and circular signal reception.

As a result of the test:
- Matching feed horn proved to provide improvement in the signal quality on the 1.2 Channel Master dish.
- Difference in signal quality between SNH-031 and SNF-031 was less on stronger transponders, but was more pronounced on weaker transponders.
- Do***ented here test was performed on a sunny day. Few smaller tests were performed on cloudy days and difference in signal quality with feed horn was getting only bigger.
- Invacom SNF-031 with feed horn outperformed others in the range 11.7-12.7 both linear and circular polarization signals (even though the tested one was not one of the best batches)
- Moded Smart and Octagon performed best of all in 10.7-11.7 GHz linear polarization. Octagon remained also generally strong in 11.7-12.7 GHz (considering it’s price – not bad at all! );
- NJR and SMW LNBs were not impressive performers. Either they are meant for other purposes (data transmission purposes, etc), or their noise of 1dB is too high compared to others (others than do not cheat by putting 0.3 dB on their LNBs?)


Special thanks to cosworth4x4 for providing moded Smart Titanium and Octagon LNBs for the test! :)

nico
13-07-2013, 09:17 AM
Thanks for this mate i have a invacom was looking at the inverto black pro or the inverto ultra as i have a long run of over 25m some say the inverto black pro is better than invacom over a long run.

Franky_D
14-07-2013, 10:39 PM
Thanks for this mate i have a invacom was looking at the inverto black pro or the inverto ultra as i have a long run of over 25m some say the inverto black pro is better than invacom over a long run.

Hi Nico,

I am not a pro, was just interested to fine-tune my system (my first expereince) and get most out of it. Therefore played with few LNBs and feed horns, which evolved into a big project. :)

I measured signal strenth on the dish (1m cable) and in the house (50 meters cable), siganl loss (attenuation) was around 12 dBuV. However, signal strength remains constant, it is something that does not change with weather, it depends on the characteristicts of the cable and LNB (LNB built-in amplifier, if i am not mistaken). Each Sat receiver has a margin of the signal strenth on the input it can decode (sensitivity), thefore of course cable length is important, but you can see straigh away if it works or not with you cable and LNB (it either works or not). 25 metres should not be a probelm at all. As i said, I am ok with 50 metre cable with both inverso and invacom.

You need to consider that Inverto might have a more powerful amplifier, but if would amplify both the good signal and the noise. So i would rather suggest to pay attention on the quality of the signal itself or "Signal to noise ratio" (called CN or SN or SNR). I took measurments of the SN on the dish and after 50 meters of cable - it was the same (with the same LNB of course). After that i was not so much concerend about cable lenth anemore. The higher SN you have, the more reserve for bad whether you get. For that matter Invacom (i tested single and quad) provided better SN than Inverto (i tested C120 single and 40mm LNBf). Therefore Invacom was overal better for me! :)

Cheers

Rizwan
10-08-2013, 06:42 PM
@Franky

I am new to forum, Please tell em, which type of Dish you have, Prime or off set ?

Franky_D
10-08-2013, 06:58 PM
@Franky

I am new to forum, Please tell em, which type of Dish you have, Prime or off set ?

It is Channel Master 1.2m offset dish

Rizwan
14-08-2013, 09:53 AM
I have prime focus Dish but quite big, about 3.5 meter, just guide me about its feed horn to pick weakest signals. Its not a branded dish and I am unable to find any type of feed horns in my Country

Franky_D
14-08-2013, 10:44 AM
I have prime focus Dish but quite big, about 3.5 meter, just guide me about its feed horn to pick weakest signals. Its not a branded dish and I am unable to find any type of feed horns in my Country

Try starting a new thread with pictures and more info about your dish. Someone might be helpful.