In Canada, the 433 MHz frequency band is shared by many consumer and commercial devices.  Devices can interfere with each other, especially in dense environments.

Common Devices Using 433 MHz in Canada:

1. Wireless Weather Stations – e.g., outdoor temperature/humidity sensors.

2. Garage Door Openers – some models (though many use 315 MHz or 390 MHz instead).

3. Remote Keyless Entry Systems – especially older car fobs and aftermarket systems.

4. Alarm Sensors – door/window contacts, motion detectors, ooften used with DSC

5. Wireless Thermometers / Barometers

6. Home Automation Devices – RF plugs, switches, or RF remotes

7. Amateur Radio Transmitters – in some cases, though hams generally use nearby licensed bands.

8. Tire Pressure Monitoring Systems (TPMS) – older or aftermarket systems.

9. Wireless Doorbells – especially from non-major brands.

10. RFID Systems – some long-range RFID readers and tags.

What can cause poor performance or connection with 433 MHz devices:

Devices in this band are often uncoordinated and low power, but interference can occur if:

• Multiple devices operate simultaneously nearby (e.g., weather station sensor + alarm + car remote).

• Devices use similar protocols or overlapping timing (causing signal collisions).

• A noisy RF environment (e.g., condo buildings, commercial zones).

How to Identify, Manage or Reduce Interference:

• Use devices with frequency hopping or rolling codes (e.g., Zigbee, Z-Wave, or newer alarm systems).

• Keep antennas separated if using multiple 433 MHz systems.

• Move to more other wireless protocols (e.g., Wi-Fi, Zigbee, or Z-Wave).

• If you're seeing interference with a known device (e.g., alarm sensors), try identifying other nearby 433 MHz transmitters with a software-defined radio (SDR).