It isn't unusual for amateur stations to benefit from additional filtering to eliminate strong AM broadcast stations. It isn't unusual for a 160 meter to pick up as much as a watt of signal--more than enough to light a flashlight! In some cases, the receiver has minimal bandpass filtering, relying on low pass filtering and the absence of strong MF/LF signals.
- Reducing Broadcast Station Interference (502,608 bytes, PDF file)
Build a BCI filter as shown in this 1976 ARRL Handbook article
- Bandstop Filters for Attenuating High-Level Broadcast-Band Signals
- Dealing With AM Broadcast Band Interference To Your Receiver (35,599 bytes, PDF file)
Joe Carr's Radio Tech Notes
- FAQ about Radio Frequency Interference (RFI)
From station KOA at 850 AM in Denver, CO.
- Morgan Manufacturing BCB Interference Filters
- DLW Associates AM Broadcast Band (BCB) Reject Brick-Wall High Pass Filter