The MFJ-1046 Receiver Passive Preselector 1.6 - 33 MHz. MFJ Passive Preselector has extremely high dynamic range! It improves the performance of nearly any HF or shortwave receiver/transceiver. It vastly improves the most expensive receivers. Especially helpful to those with broadband front-ends that are prone to overload. Protects your sensitive receiver input from damage (including switching diodes and attenuator resistors) caused by very strong signals from multi transmitter, multi-band operation -- contests, field day, nearby hams, CBers, TV/FM/AM stations.

It eliminates phantom signals by suppressing strong out-of-band signals that cause intermod, blocking and cross modulation. Completely eliminates second order intermod problems caused by strong out-of-band shortwave broadcast signals mixing and producing unwanted in band signals. MFJ unique Hi-Q series tunable circuit gives you superb performance. The tunable series tuned circuit works into a very low impedance formed by broadband toroidal transformers.Has narrow bandwidth, excellent stopband attenuation, very low loss, constant bandwidth and gain over each band. Excellent attenuation in adjacent contest bands. The entire 1.6 to 33 MHz HF band is covered in five overlapping bands. Fully shielded metal enclosure. Tough black finish.