Re: Frustration with X10 Powermid

[Joerg <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx>]

Hello Dave,


> The Powermids use 418MHz RF which is by and large unused except by other
> remote extender devices like the Powermid. ...


No idea how selective their RF filter is but the ham radio band of
430-440MHz is close by. If there is an active ham or a repeater in the
area it might interfere. Then there is the ISM frequency at 433.92MHz
which is used by all kinds of stuff such as remote thermometers.

On 418MHz there is some other usage as well. Wireless alarm systems,
garage door openers. While the transmissions are intermittent and
usually brief some cheaper systems might use those dreaded
"super-regenerative" receivers. Some of those are constantly spewing RF.


>                                    ... The IR receiver has a grounded
> metallic shroud. RF interference is one of the least likely explanations
> except for strong local sources near the 38kHz IR carrier frequency. A
> nearby TV (as Bobby Green suggested) is one possible source - harmonics from
> its horizontal sweep are the source.
>

Then there are the "modern" switcher supplies. Today almost anything has
these. Laptops, printers, video games, fax machines, LV halogen lights
and so on. Often they try to get away with the least amount of RFI
protection that makes them barely pass. On some of them I wonder whether
they ever passed.

Regards, Joerg

http://www.analogconsultants.com