We are doing some FCC testing of our Electron device, and we are failing the tests at a few frequencies that seem to be correlated to the Electron’s clock. Specifically, these frequencies are: 147 MHz, 175 MHz, 198 MHz, 240 MHz and 257 MHz.
Some background: we have a PCB the Electron mounts to that is relatively simple FCC-wise, as it has no other intentional radiators and no other noisy components other than possibly our switching regulator. Also, this is one of a few leads we are chasing down for not passing these tests – we plan to adjust a bunch of other things the next time we go in.
Next time we go in, we plan to put Electron in deep sleep, to eliminate this as a possibility, but in the meantime, we’d like to play with the Electron’s internal clock speed to see if we can adjust these peaks.
So my questions are:
- Has anyone experienced a similar issue? Anyone else gone through FCC unintentional radiator testing with Electron?
- Are there any consequences of changing clock speeds that may be unintended? Like modem communication goes haywire?
- I plan to adjust clock speeds by editing this file.
- Is this the right place to adjust clock speed?
- Is there an API, like through a STARTUP() macro that might be a better place to do this?
Thanks in advance for any input!