I have a small electronic device that I'm considering bringing to market. It doesn't have any features like wifi or bluetooth, so one of the prerequisite steps before I can sell it is to ensure it doesn't exceed FCC emissions limits for an unintentional emitter.
However, emissions testing can be expensive. I've gotten quotes from 3 different labs, and the cheapest one was $1100, and that if you fail the test, you'll need to fix your device and then pay for an additional test. So obviously, I want to do everything I can to ensure I pass the test on the first try.
I've read online that a good way to get a general sense of your device's emissions before testing is to buy an AM radio and see what effect the device has on it. So I bought a generic $8 AM/FM radio and I found that my device does indeed effect the AM channels. From 10 feet away, I tuned into the clearest channel I could find, and then I monitored the reception as I got closer. From 1 foot away, the reception is still perfectly clear. From 6" away, there's a noticeable whistle and extra static in the reception. From 3" away, the channel is completely static.
I did a similar test with the FM reception, and there was no interference at any distance.
So my question is, how do I determine if this means my device wouldn't pass verification testing? I know my description isn't terribly quantifiable, but is there a general rule-of-thumb for this kind of thing? Is complete disruption of AM reception from 3-6" away considered unacceptable by the FCC? I've been personally using my device, and have had it running continuously for over a month, and I haven't noticed any negative effects.