X10 - PIRs - MS13 and MS14

[Robin]

'afternoon.

I'm in the UK, and I'd like to connect some external wireless PIRs into
my home network. Unfortunately, there is a dearth of X10 compatible
devices because the frequency of the MS14 (external PIR) is restricted
to military use (!).

Given that the MS13 (which is available and legal in the UK, but is
really for indoor use) looks very similar to the MS14, is it possible to
dismantle the innards of the MS13 and put them in an MS14 case?

Thanks & regards
Robin

[vincentb]

There is one 'hacky' way you could do it. Open up an MS13 and cut the light-dependent-resistor off. Then connect those two wires to your other motion sensor's contacts. When that motion sensor triggers, it will short out the MS13's light-sensor. Programme the MS13 so that its motion doesn't work but it's sunset detection does. That way it only sends an X10 signal when the other motion sensor triggers.

but remember, the sunset-detection is one unit code above the motion's unit code. so if you programme the MS13 to B4, for example, it will actually transmit B5 when the sunset-detection wires (that are connected to your other motion sensor) are shorted.

Or you could wire up your motion sensor to a device that injects an X10 signal directly in the mains when its contacts are shorted. Have a look at the AIX12 product, made by a company called Xanura. It works on A10 (which is compatible with X10, but with 10 times stronger signals, to alleviate inteferences).

Here's an example:
www.futuretouch.com.au/productsinfo.asp?productcode=AIX12

That is, if you have the ability to connect such a device to your mains, where the motion sensor is located.