SatSig topic:

Satfinder tuning: ku-band and c-band

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Nov 24^th, 2009 at 10:06am

hello, is it possible to use the one frequency to lock both ku and c-band on the same satellite using a sat finder? for example using a frequency like 10986 MHz on ku-band and the same for c-band. i have sat finder i normally used. now i want lock a C-band on nss7, can i use the same frequency that i used on ku-band for this C-band?

Nov 24^th, 2009 at 10:58am

The satmeter is an L band measuring device, with an input, via the LNB cable, in the range 950 - 2150 MHz.

If you set a frequency like 10986 MHz, the meter must also have a LNB local oscillator frequency set, say 10 GHz. In this case the meter will actually tune to 986 MHz.

With the meter so configured it will continue to measure at 986 MHz, regardless of what LNB you connect, low band Ku or high band Ku LNB or C band LNB. If you use a C band LNB with LO=5150 MHz you will actually be listening for a carrier at 4164 MHz. (986 = 5150 - 4164). It is unlikely that your wanted C band carrier is at this frequency. The symbol rate is also likely to be different from your previous Ku band service.

You will be confused if the LNB local oscillator frequency set in the meter is not the same as the actual local oscillator frequency of the the LNB connected.

To find a C band carrier, set the meter LNB local oscillator frequency to 5150 MHz and enter the C band satellite frequency e.g. 3950 MHz. The meter will tune to 1200 MHz. ( Most C band LNBs have 5150 MHz as their local oscillator frequency, a few have 5750 or 5950 MHz )

I, personally, prefer to use meters in simple L band mode 950-2150 MHz, and do the calculation on paper. Cable frequency = difference between satellite frequency and LNB LO frequency.

Before it finds, or fails to find, a carrier, the meter will act as a wide band power meter and detect any noise source in the range 950-2150 MHz, e.g. any satellite or the sun.

Best regards, Eric.

Nov 24^th, 2009 at 11:27am

thank you sir for the reply. i want to lock a c-band on nss7 (west africa beam) and from this site https://www.lyngsat.com/nss7.html, what frequency can i use or how do i calculate for the c-band frequency.i have my sat finder lnb LO set to 5150.

Nov 24^th, 2009 at 12:21pm

What polarisation do you want ?

South East Zone beam ?

East hemi beam ?

I would pick some large DVB carrier, but not DVB-S2.

Best regards, Eric.

Nov 24^th, 2009 at 12:49pm

thank you so much. now i understand. am new to c-band so one told that i could use the frequency that i do use to lock ku-band to lock c-band. i did it but it didn't work.but with the picture u have given me now i will go back to site and use either frequencies on SE or East Hemi. the footprints covers the area am working.thank you so much.
stay blessed