For the Norsat 9000LDF:
- RF input: 21.200–22.200 GHz
- LO: 20.250 GHz
- IF output: 950–1950 MHz
The relationship is:
IF = RF − 20.250 GHz
So in SDR# you tune to the IF frequency. Some examples:
| RF frequency | SDR# tune to |
|---|---|
| 21.200 GHz | 950 MHz |
| 22.23508 GHz (water maser) | 1985.08 MHz |
| 22.200 GHz | 1950 MHz |
For 22.23508 GHz water maser observations, set SDR# to 1985.08 MHz (or 1985.080 MHz if entering kHz precision). That is the correct centre frequency before making any small Doppler or calibration adjustments.