It Happens Every Year....

[Jack Brindle]

Jerry;

You can pretty much rule out solar conditions - things are very quiet  
on the sun right now. The ham bands are rather quiet as far as noise  
is concerned, especially as you go up in frequency. I believe the X10  
stuff runs around 300 MHz, which tends to be somewhat low in noise  
anyway. I would suggest that you are not seeing anything that is  
common to other folks.

However, there is a LOT of man-made RF noise these days. The RF noise  
floor is dramatically higher these days due to all the electronic  
toys we folks have, from plasma TVs (especially bad) to noisy  
computer supplies (the PC users know about these) to lots of other  
things. I am troubled by power line noise from the old pole  
transformer in my back yard - it usually gets better after it starts  
raining hear this time of year, but it is getting worse as the  
transformer ages. There are lots of potential causes - you get the idea.

I would suggest you try to look around to see what changes just after  
Christmas - perhaps people start turning off their Christmas lights  
and thus change things in the power grid? Could there be a street  
light that is operated by a light sensor that has gone bad? That  can  
be especially bad for RF interference (RFI). These usually show the  
most trouble around sunset or sunrise, but it the sensor is bad all  
bets are off. But they usually don't fix themselves as soon as  
February comes around. In short, look at the environment to see what  
is different during this period. It probably is not something that is  
weather-related, unless it gets dramatically warmer where you are  
after the "bad" period.

Solving RFI problems is an endeavor that drives people crazy - kind  
of like figuring out why important connectors fail when dropped to  
-275 degrees or so... ;-)



On Jan 14, 2008, at 3:42 PM, Jerry — MacSolutions wrote:

> I've brought this up in the past but I'm still looking for an  
> answer...
>
> Each year, right around the end of the year... Starting from just  
> after the Christmas break to perhaps the second week in January, my  
> wireless signal are semi covered by what I guess is just RF "noise."
>
> What happens is that normally bulletproof sensor/light/script  
> combinations start missing each other.  It might take two triggers  
> of a motion sensor to get through to trigger a light. There's no  
> record in the log of the first trigger but usually, the second  
> wireless signal gets through and triggers the script.
>
> Does anyone else notice this, around this time of year?  I guess my  
> mind is drifting towards some type of atmospheric condition that  
> only appears during this time and fades in and out slowly.  I'd  
> start it right on the Winter Solstice which is why I credit it to  
> something natural.
>
> By next weekend, it's faded to the point that I don't notice it any  
> more until the following year.
>
> Or, am I losing my mind? hehe  It's been happening for at least 5 +  
> years now like clockwork....
>
> Jp
>

- Jack Brindle, W6FB
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