Mark: I would refer you to title 47,part 15 of the code of federal regulations. 15.103 lists exempted devices and 15.103h shows that 'digital devices in which both the highest frequency generated and the highest frequency used are both less than 1.705 MHz and which do not operate from the AC power lines or contain provisions for operation while connected to the power lines' are exempt. My from the hip reaction to your blinker would be that if you used a low frequency external RC to generate timing (so that no harmonics approaching 1.705 were existant for all practical purposes) you would have no problem whatsoever. Note that a digital device is by definition an unintentional radiator so you can't cheat and have a battery powered 1 MHz transmitter under this exemption. Of course under this exemption you are required to shut the device down if it is found to cause interference. I would assume the security system operates or at least can operate off of AC so you start to have to pay more attention. To wander a bit, this reminds me of a story I heard about the early pple ][ days. The RF modulator which allowed the machine to be hooked up to an ordinary TV of course violated some of the intents and letters of the FCC regulations which allowed for relatively easy certification of the computer itself. If Apple sold the RF modulator, it would cause the entire system to fall under the stricter rules. So instead, they inserted some verbage in the documentation to the effect of: 'hey, sorry we can't help you with the RF modulator, but we have heard of this guy that makes one and you might want to call him.' He had originally, as I understand it, agreed to build and sell these devices just to help his friends along with their new business but as history unfolded, he ended up making quite a pretty little penny with this product. Brian Disclaimer: for all legal intents and purposes, a squirrel broke into my office and typed this note. Neither me nor my employer bear any responsibility. -----Original Message----- From: Mark Winters To: PICLIST@MITVMA.MIT.EDU Date: Wednesday, February 18, 1998 1:35 AM Subject: Any PIC-based Product NOT require FCC Approval? >Hello All, > >My apologies for the "newbie" question -- I was hoping someone on this list >might know or could point me to information on how to find out if a product >requires FCC approval before selling it commercially. >