Your lacking in the details here. But in trying to read between the missing lines, I would say that when you transmit, you have way too much RF in the room. This can be caused by a number of things. The first would be a high SWR from your antenna. You could have some poorly shielded coax cables being used. The transmitter is lacking a good, low resistance earth ground. The transmit antenna is too close to the detector. My last guess is the detector is poorly designed and is sensitive to the RF from your transmitter.Everytime I fire up my Heathkit SB 201 amp the carbon monoxide alarm goes off in my shack
Does anyone know why this happens and what can I do to prevent it!