On 10/7/2010 8:24 AM, Michael Coslo wrote:
> Good morning, all.
>
> I do a little contesting mobile. For this use, I have a laptop that I run off
> an inverter. It's the typical 800 watt not-quite-sine wave inverter that
> unfortunately puts out a fair amount of RFI. I'm pretty certain that the
> interference is on the power line, there may be some radiated too, but I can
> hear it with no antenna connected. Has anyone found any sort of solution for
> this sort of thing?
Two suggestions.
First, wind multiple turns of the AC cable through a #31 or #43
Fair-Rite toroid or big clamp-on. See the Choke Cookbook and the
measured curves in Appendix One, and use a number of turns that puts the
resonant peak where it will cover the frequencies of interest.
http://audiosystemsgroup.com/RFI-Ham.pdf
Second, if you still have noise, add a commercial line filter, like one
of those shown in
http://audiosystemsgroup.com/PowerFilters.pdf
My educated guess is that the choke will be more effective than the
commercial filter, but you never know. FWIW, these inverters are well
known to put out a lot of trash.
73, Jim Brown K9YC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|