The basic frequency response of the switched low-pass filter bank of an HF Packer Amp V4 is shown. This amplifier is designed to deliver about 35W output with about 2.5W drive power. It covers the HF bands from 160m up to 10m. The low pass filtering for the amp is implemented as a set of multiple filters which are selected using a rotary switch. Relays are used to switch the selected filter in-line. I made a set adapter cables to connect the filter to a spectrum analyzer and tracking generator to make the measurements.