SatSig topic:

universal lnb LO

(Read 11150 times)

Oct 23^rd, 2013 at 10:55am

Hello,

I want to know the LO value that can be input on satlook or other satellite tracking devices when tracking or working with a HX universal LNB PN 1501882-0002? Like the regular LNBs that uses either 10.000/11.300/5.150 for ku and c-band respectively.
please i really want to know?
regards,
edwin.

Oct 23^rd, 2013 at 9:33pm

Well, "universal" isn't really universal - unless it's switchable. Here in America, the LOF freq for Hughes Ku-band is 10.75GHz. But satellite frequency planning established by the FCC and the ITU mean different LOFs in different parts of the world. A North American TRIA for example, cannot be used with satellites covering Europe or the Middle East. Probably not Eastern Asia or the Western Pacific either. These areas may be where the 10.6 and 9.75 come in.

//greg//

Oct 24^th, 2013 at 1:07pm

thanks for the reply. but my issue is that, when working with universal lnb and set my satlook (lnb type) frequency to universal it doesn't display signal lock. unlike when working with other lnbs and set the lnb type on the satlook to either standard/user or maybe input the lnb LO i can easily get signal lock.
so if i have to work with hughes universal lnb and want to track with satlook what LO can i input on my satlook to have a display of signal lock?

Oct 24^th, 2013 at 2:22pm

Perhaps I wasn't clear the first time. When considered on a global basis, "Universal" seems to be as a bit of a misnomer. LOFs necessarily vary by geoloco.
As stated, it's a frequency management thing relative to frequency re-use and non-interference. You must first be using a LNB that has a LOF that can actually detect the baseband of satellite at which you're viewing. Then you must tell Satlook the the LOF used by the LNB. If your LNB can't "see" the satellite, then Satlook can't see either.

Your profile doesn't reveal your own geoloco either, so we don't have a clue regarding at what or where you're looking. There's not much else anybody can do short of telling you that you have to input the LOF used by the satellite you wish to view.

//greg//

Oct 24^th, 2013 at 3:57pm

At Ku band, the satellite frequency minus the LNB local oscillator frequency equals the modem/receiver tuning frequency.

Modem tuning range varies from one model to another. 950MHz is the common minimum frequency. The upper end of the tuneable range is between 1450 and 2150 MHz, depending on manufacturer and model type.

Consider the tuning range of your modem/receiver device (e.g spectrum analyser, satmeter, iDirect, Hughesnet etc) and coupled with the local oscillator frequencies of what LNBs you have you can work out what satellite frequencies you can successfully receive.

Examples:

If you want to receive at 10.701 GHz you will need a LNB LO = 9.75 and the result will be 951 MHz.

If you want say 11.723 MHz you could use either
LNB=9.75 and tune to 1973 MHz
LNB=10 and tune to 1723 MHz
LNB=10.75 and tune to 973 MHz

If your modem receiver has a narrow tuning range you are going to need more LNB LO frequencies to cover the whole range from 10.7 - 12.75 GHz.

Satellite TV uses "universal" LNBs with two alternative local oscillator frequencies, 9.75 GHz and 10.6 GHz with the higher frequency option selected using a 22 kHz tone injected into the cable. Such an LNB may be used to receive 10.7 - 11.7 GHz using the lower 9.75 GHz LO frequency or the higher band 11.7 - 12.75 GHz using the higher 10.6 GHz LO frequency. BUT you must have a wide tuning receiver that goes from 950 to 2150 MHz.

Many VSAT modems/receiver do not go up to 2150 MHz.

Read more here: https://www.satsig.net/lnb/explanation-description-lnb.htm

Best regards, Eric