I want to do some bench testing on a new to me radio before installing into my panel. If the radio stays in receive mode only do I still need an antenna or dummy load on the antenna input? Can anyone recommend an appropriate dummy device that can be used on an aircraft radio or a circuit that can be fabricated without too much trouble? How about something like the Diamond DL30A https://www.hamcity.com/store/pc/DL30A-p1874.htm. Thanks.