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I've been spending a lot of time looking at 47 CRF 15, and specifically .231, and I don't understand how these limits are possible for many products. I'm designing a remote control for a product that needs to work from 150-200 feet away. It has 6 buttons and is addressable with DIP switches, so the amount of data being sent is tiny. It's basically a glorified garage door opener.

I have a product that is similar to the one I'm designing, and it has the range I need, but the specs say it outputs 10mW or 10dBm, and if I'm reading the FCC guidelines right, that's 1000 times the limit.

A couple more specs in case it matters: the transmitter is based on the PT2262 chip, and is operating at 315mHz using a 12V battery with an antenna on the circuit board traces.

My question is 1) How can I build something that has 150-200 ft. range and still be within FCC specs? 2) Am I reading something wrong or is there some exception that will let me pass FCC or avoid it? 3) How do other devices, like garage door openers, get away with it?

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1)place to look eqn 9 is what you'll need.

2) no exceptions, unless you get a registered device and go through that hassle -> or move to ISM band

3) they get away with it but not being able to connect at those distances. The power limits are there to limit the locality.

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  • \$\begingroup\$ The formatting you are using here could use some work, his answer seems readable to me but a little effort on formatting could go a long way. A bit of clarity as to why you have numbered things would be useful also. \$\endgroup\$ – Kortuk Sep 28 '12 at 2:42
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{{Not a lawyer}} I think you need to take a look at Part 95, http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=630ae6c5c880913bde8361f9e084518c&rgn=div6&view=text&node=47:5.0.1.1.5.3&idno=47 Re: radio controlled devices. In short it appears you may use the 72-76 Mhz bands at a maximum of 0.75 Watts (Rule 95.210). You may use a non-FCC certificated R/C transmitter on Channels 26.995–27.255 MHz if it complies with the technical standards (see part 95, subpart E).

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