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Justin Crooks
Moderator
BBowar,
The USB-SA44B has higher LO feedthrough than other models we sell, and the LO is offset by only 10.7 MHz. You can minimize it by setting a reference level around -30 dBm (which will turn on the RF preamplifier), or manually turning gain to 1, preamplifier on, attenuator to 10 or 15 dB. This should reduce the LO feedthrough to around -60 dBm (typical).
Choosing a product like the BB60C will keep LO feedthrough below -80 dBm, and will keep the LO > 1.2 GHz away from the RF.
You can also add a circulator, ore even an external attenuator and/or preamp, to reduce LO feedthrough if needed.
