Converting a US 300MHz RMS18/MS12A motion sensor to transmit at 433.92 MHz

For those who are interested in modifying a US RMS18/MS12A to transmit at

433.92 MHz into I have written an tech doc for the modification. It is located at:

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regards Stefan

Reply to
Stefan van der Horst
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Forgot to mention this is an X10 device

Reply to
Stefan van der Horst

One correction: The US frequency is 310MHz.

You also should be aware that the FCC severely restricts the power that can be used by these devices. CE power limits are much higher. So while you might save a bit (assuming your time has no value) this way you'll end up with much less range than with the European versions. See...

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A simpler approach might be to merely disable the 310MHz circuitry and add a

433.92MHz RF transmitter module. There's a small 4-pin transmitter widely available (Velleman, CrownHill, etc.) that will work quite well and has a higher power output than the US X-10 devices.

I've d>Forgot to mention this is an X10 device

Reply to
Dave Houston

Hi Dave

Thx for the 310 notice. I changed the article.

The RF transmitter I build is 100% the same as the RF transmitter installed in the european MS13E motion detectors. The current and voltage provided to the RF module are the same as the european models. I don't have the equipement to test the power but I was able to span app 30 meters in open field and 20 meters in house through brick walls.

I'll add your link to the article as well.

For my purpose the rf power is high enough.

Reply to
Stefan van der Horst

Dave

One more thing, the purpose was to be able to use the US versions in Europe main land. Not vice verse.

Reply to
Stefan van der Horst

Reply to
Dave Houston

I should have read your article before commenting. ;)

I now see you are changing the components that control the output power.

S>Hi Dave

Reply to
Dave Houston

Actually, the changes you make *reduce* the power. It's the added antenna that gives you extra range.

Here, solder>I should have read your article before commenting. ;)

Reply to
Dave Houston

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