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

["Stefan van der Horst" <stefan@xxxxxxxxxx>]

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.

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:43c6cc5b.105778578@xxxxxxxxxxxxxxxx
> 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...
>
>     http://www.radiometrix.co.uk/apps/apnt102.htm
>
> 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 done the reverse, adding a small 310MHz transmitter to the DigiMax
> 210
> RF thermostat sold by X-10 Europe.
>
> "Stefan van der Horst" <stefan@xxxxxxxxxx> wrote:
>
>>Forgot to mention this is an X10 device
>>
>>"Stefan van der Horst" <stefan@xxxxxxxxxx> wrote in message
>>news:dq6f7k$i30$1@xxxxxxxxxxxxxxxxxxxxxxxxxx
>>> 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:
>>>
>>> http://project.actopus.nl/X10/rms18toms13/Index.html
>>>
>>> regards
>>> Stefan
>>>
>>
>