FT8 sets off my Kiddie Smoke Detectors

[KD2TZD]

Hello, all. I recently got my ticket and just set up my first HF home shack. 100W ICOM 7300, Super Antenna set for 20m, and MFJ RF Isolator (near transceiver). SSB has been working. I tried FT8 twice and both times after less than a minute it has triggered all the Kiddie PI2010 smoke detectors in my two story home to alarm. When I stop the FT8, they stop too. These smoke detectors have a feature where when one goes off, it’s sound triggers the rest within ear shot to go off too. My super antenna is in the attic, and is less than 7 feet away from the closest detector in a bedroom. My current best guess is that SSB duty cycle is not full 100W but FT8 is, and the antenna is too close to one of the smoke detectors. But, I thought I’d ask the smart people here before I start down rabbit holes. Not a lot of options for the antenna placement in my attic. I’m in an HOA, so I tried to defer the outdoor antenna, and get on the air asap. I’d like to do the digital modes.

[VK3RX]

Before trying ferrites on your smoke detector wiring, try cranking down your output power and use the minimum extent necessary

The data modes like FT8 etc. work well with minimum power, which is why they are popular for those in restricted housing environments like you, retirement villages etc.

[KD2TZD]

Yes, when I keep FT8 below 20W, it does not trigger the smoke detectors.