The correct BUC Local Oscillator (LO) frequency is essential if you want to transmit on the correct frequency. Acquiring in to a TDMA network or closing a SCPC link with the wrong BUC LO will be impossible and cause interference to other users in the network. Typically from the indoor modem to the BUC is L band frequency and sometimes 70MHx Intermediate Frequency (IF) due to the high losses when higher frequencies are transmitted over coax. The BUC will then convert this frequency with the Local Oscillator (LO) frequency to output the C, Ku or Ka band for transmission to the satellite.
Common BUC LO Frequencies
The LO can be found on the manufacturers specs sheet or printed on the label on the BUC.
Typical LO’s for Satellite Communications:
You have to select the correct BUC LO for the modem/network (i.e modem L band).
But what if you cant read it or don’t have access to the spec sheet? It can be easily calculated by using the BUC frequency range.
BUC LO Frequency Calculation
Using the example above you can simply use the lower or upper RF frequency range(output or input).
5850 – 950 = 4900 MHz LO
6425 – 1525 = 4900 MHz LO
The LO for this C band BUC is 4900MHz.