Second Hand Monacor FSI-40 FSI-40 SWR Power 1.5-150MHz Meter
DL4PP: Amateurfunk Messgeräte/Zubehör
Monacor FSI-5 Power SWF Meter CB Watt Power Antena - Etsy
Would anybody know what the knob in the middle of this meter does? I was given one like this by a friend but not sure how to operate it. Thanks for the