To set the center frequency in rtlamr, use the -centerfreq flag followed by the desired frequency in hertz. For example, to set the center frequency to 451.050 MHz, you would execute:

This command configures rtlamr to monitor signals centered at 451.050 MHz. Ensure that the frequency is specified in hertz (Hz) without any separators or decimal points.

It’s important to note that rtlamr is primarily designed to decode signals from Itron ERT-compatible smart meters operating in the 900 MHz ISM band. While you can set the center frequency to other values, such as those in the 400 MHz range, rtlamr may not decode signals outside its supported protocols.

If you’re attempting to monitor devices operating at 451.050 MHz, ensure they use a protocol compatible with rtlamr. Otherwise, you might need to use other tools like rtl_433, which supports a broader range of protocols and frequencies.

For more detailed information on configuring rtlamr, refer to the Configuration section of the rtlamr Wiki.

Additionally, if you’re interested in monitoring devices operating at 433 MHz, you might find this discussion helpful: Meter Reading – Hardware – The Things Network.

Always ensure that your monitoring activities comply with local regulations and respect privacy considerations.