> -----Original Message-----
> From: Chuck Gooden - N9QBT
> I am having RFI problems with a Nighthawk CO2 detector when I operate on 40
> Meters. Does anyone have any Ideas on how to get rid of this problem.
>
> I am planning to try a Ferrite core on the AC Line (hot lead only) inside the
> electical box as soon as I can get some but any other ideas would be welcomed.
>
If the signal is coupled to the line in differential mode, then this
might work although in in-line coil would work better; but usually it's induced
common mode onto the line. If it's common mode, then you need to wrap the
whole power cable (hot, cold & grd) onto a ferrite. Here's a diagram (hope it
comes through OK):
Differential Mode:
induced signal path ----->
______________________
AC POWERLINE ______________________
<-----
Common Mode:
<----------
____________________
AC ____________________
<----------
> The CO2 Dector is Model KN-COPP-3, Assembly #900-0076, Manufactured 17 April
> 2000.
>
Be sure to contact the mfr to let them know about the RFI problem.
Usually, telling customer service is a waste of time. Find the people who care
about such problems (if they even exist!).
73,
de ed -K0iL
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