📡 STB DATV Calculator

When feeding a DATV signal directly into a set-top box (bypassing the LNB), the STB still applies the LNB local oscillator offset internally. Enter your transmit frequency and the STB's LNB LO frequency to find the transponder frequency you need to tune the STB to.

Transmit Frequency (MHz)

STB LNB LO Frequency (MHz)

Common LOs:

Tune STB Transponder To

11000 MHz

9750 + 1250 = 11000 MHz

How it works: A set-top box expects to receive a signal that has already been downconverted by an LNB. The LNB subtracts its local oscillator (LO) frequency from the incoming satellite frequency. When bypassing the LNB and feeding a signal directly, you need to tell the STB a frequency that, after it internally subtracts the LO, matches your actual transmit frequency.

Formula: Transponder Frequency = LNB LO + TX Frequency

Example: Transmitting at 1250 MHz with a 9750 MHz LO → tune STB to 11000 MHz.