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Re: Re: QRM ON 2.4 GIG

Rick Fletcher wrote:

> Good chance it's one of the 2.4GHz wireless phone systems.  I have one in
> house (had it for a while before I got onto AO-40) and I have to power it
> down to work AO-40.  It puts out strong pulses approximately once a second
> which is an announcement message to any handsets within it's operating
> perimeter.  I also have an 802.11b wireless LAN system at home, but it has
> never been a problem.

Wayne replies:

What's the frequency range of the 2.4 GHz cordless phones?  It may not be
very practical to build a bandpass or notch filter if the frequency is very
close to 2401 MHz.

In my case, the offending pulses are to my southwest.  The nearest structure
in that direction is about 1/4 mile away.  But I'm sure a dish could hear a
2.4 GHz cordless phone much further away than that.

My immediate area has a relatively low population density (a combination of
empty fields and acre lots).  2.4 GHz interference must be much worse in
more densely populated areas.  I only hear one pulse (one phone, I suppose),
and it only degrades AO40 reception when the dish is pointed to the
southwest.  With the noise blanker on the pulse is barely audible when the
antenna is pointed in other directions.  I suppose that over time more
neighbors will start using these phones and I will get much more

Wayne Estes W9AE
Mundelein, IL, USA

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