SatSig topic:

C band LNB local oscillator frequency & stability

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Apr 24^th, 2007 at 10:56am

Hello with all
I come to acquire information compared to the Viasat equipment which we use in C band. The stations who are running have an LNB whose characteristics are: Freq: 3.625 - 4.2 GHz, LO: 5.15 GHz. Actually we have an LNB whose characteristics are: Freq: 3.625 - 4.2GHZ LO: +ou- 25kHz.
My question is as follows; can these LNB be compatible. Thank you

Apr 24^th, 2007 at 12:03pm

Yes, it is most likely they are compatible. If you read the manufacturer and model number you will be able to find the local oscillator (LO) frequency of the LNB for certain.

The output frequency into the cable is the difference between the satellite downlink frequency like 4000 MHz and the LO frequency 5150 MHz, in this case 1150 MHz, which is in the L band tuning range of the LinkStar receiver. Note that the signals into the LinkStar are inverted.

An LNB with a LO frequency stability of a little as +/- 25 kHz is a very good one.

Typical C band LNB will have a local oscillator (LO)frequency of 5.15 GHz and a stability of +/- 100 kHz or more. This does not matter if you are receiving a big carrier, like 20 MHz wide, but is not suitable if you are trying to receive a narrow 64kbit/s carrier as you might not find it.

Go here for explanation description of C and Ku band LNB
wxw
Best regards, Eric.

Apr 24^th, 2007 at 12:41pm

Hello and thank you for your answer.
I does not able to logger on the sat with my second LNB.The led sat makes only clignonter, then it may be that J have another problem. Which are according to you the elements which I can blame. Once again moreover all my considerations has you for the fact of your explanations which are useful so much.
Thank you

Jun 3^rd, 2007 at 1:07am

i need help to point my antenas at atlantic bird 3 at 5 deg
my position is LAT N18.28 and LONG E 1.24
if someone can help me please

Jun 3^rd, 2007 at 9:50am

Using this page: https://www.satsig.net/maps/satellite-dish-pointing-west-africa.htm
I get the following satellite dish pointing results:

wxw
Best regards, Eric.