"Certainly, it's just a matter of time before the FCC casts an eye toward theremins" - Thomas
About CE / FCC EMC Compliance:
Here in the UK (and Europe) one needs to go through compliance in order to sell ANY electronic product.. This compliance covers aspects such as safety and RF issues such as susceptability to EM and the instruments output (radiated emissions) and (if connected to mains) any rubbish one sends up the power line - Then there are additional things like Restriction of Hazardous Substances (RoHS).
Even for an event like the 2010 "Hands Off / Ether" Festival in London South Bank Centre, I was required to obtain independent certification of the theremins - Because they were mains powered, they required verification that the EC Low Voltage Directive was being complied with - and I had to have one checked for EMC and certify that the others would be built identically. (change the length of one wire and technically you are in breach)- Each theremin was tested for safety (at my expense) by a certified tester, and then each was again tested by an inspector hired by the client...
EMC which could affect things like security systems or personal appliances like 'phones are seen as an insurance risk. - Fortunately I didnt need to comply with immunity directives (as in, it wasnt critical if someones mobile phone screwed up the thyeremin) - Not because this would have been a problem, but because this is the most expensive test, by far.
I nearly bombed-out of HO-2010 because I was advised (after I had ordered the PCB's and components) that I must insure the instruments against public liability (or rather, insure the public againstb the instruments), for the duration of the show - £2M insurance was required - and insurance was not available without certification.. After a lot of argument the client payed the cost of the insurance (I told them I would bill them for my expenses and back out if they didnt) - but I was left bearing the certification costs... One reason I made a big loss on the project.
But - Provided the theremins frequency is low (probably below 1MHz, mine were below 500kHz) and the waveform on the antenna is reasonably pure, getting through the compliance testing for EC requirements was no big deal - My theremins were radiating about 30% of permitted levels for this catagory of appliance.. I understand that FCC regulations are more-or-less unified with CE regulations.
If one doesnt need outside certification for insurance purposes, one can self-certify equipment within certain classes* (at least for CE .. This is what I usually do - not sure if one can self-certify for FCC) - You need to produce a technical reference file detailing the design, calculations, measurements and factors which you believe justify the certification - and this must be available for inspection... But unless a serious complaint is raised against your product, nobody investigates... Sadly, this is the reason that so many awful non-compliant noisy products get onto the market with a CE mark.. Made (mostly) in China, If detected, the only action taken is prevention of sale and perhaps a fine on the importer.
Fred.
*Anything safety-critical requires external or approved certification, and some products like vehicle or aircraft parts, fuel systems and the like require full compliance testing by a certified test lab.
