[Jim]

Originally Posted by J_Player

From what I have read, the Examiner is not a transmitter, but a receiver. The signal that determines the resonant frequency tuning for the Examiner is derived from the EMI emissions from a nearby calculator as well as a low frequency millivolt signal from the operator's body. But the actual power that drives the Examiner circuit is derived from atmospheric static electric field differential between the antenna altitude and the ground path in the operator's hand. From what I read, the examiner does not send a signal. It receives a signal if one is present in the air at the resonant frequency it is tuned to. In essence, if you hold a hold a non-powered circuit board with an ariel soldered to it in your hand while your feet are on the ground, you are generating a similar amount of power and RF interference as the Examiner from another passive circuit into the atmosphere, which I suspect is below level of ambient EMI/RFI interference in the air.

Now, if you are suggesting that Part 15 would require the circuit board with an ariel soldered to it must have some FCC certification because the operator is holding it outside where there is a static voltage gradient in the air, then I would think all electronic circuits that are hand-held outside in the air must also have an FCC certificate. Maybe holding a piece of wire in the air must also have an FCC certificate. Somehow, I haven't yet seen any FCC stickers on the spools of wire at the supply houses, nor do I see FCC stickers on miniature crystal radio receivers, or sticks used to rub together to make fire. Maybe this is the reason why Part 15 is not specific to what equipment requires the approval. Maybe they want to require approvals only for circuits that use enough power to generate some interference above the ambient levels found in relatively quiet EMI areas (ie: devices that show measureable radiated power that could cause interference in consumer electronics). But then, I am only speculating. Perhaps you know better.

Best wishes,
J_P

Thanks for your reply.

I read that the device has a resonant frequency amplification circuit. That's an awesome feat of engineering for a calculator!?

Maybe the Buc's will go to the Superbowl this year (adding to the maybe-feast)