This video shows how I used an SDRplay receiver and spectrum analyzer software to find the source of intermodulation problems that were interfering with my scanner radios. Then I used a filter from PAR Electronics to cure the problem.
PAR Filter: http://www.parelectronics.com/index.php
SDRplay: https://www.sdrplay.com/
Stridsberg Active Multicouplers: http://www.stridsbergeng.com/
