What type of filter should be connected to a TV receiver as the first step in trying to prevent receiver overload from an amateur radio HF transmission?

To prevent an HF (High Frequency) signal from overloading a TV receiver, you need a filter that blocks the lower HF frequencies while allowing the higher TV broadcast frequencies to pass through. A high-pass filter installed at the TV receiver's antenna input perfectly achieves this. A low-pass filter would do the opposite, blocking the TV signals while letting the HF interference through, which is why a low-pass filter is used at the HF transmitter to block harmonics, not at the TV. Band-pass and AC line filters do not address the specific issue of strong RF entering the TV's antenna terminal.