Mike,
I am wondering if using a type 73 material would improve things for HF
operations? Looking at a chart for various ferrite materials I note that
type 43 (which you used) peak impedance is around150 MHz while type 73
shows a peak around 25 MHz.
Comments?
73
Danny, K6MHE
At 09:54 PM 3/22/2005, Mike wrote:
>Hi Clay,
>
>We use a Honda ES6500 at our Field Day site without any special
>line filtering and don't have any problems with noise. That is not
>to say that it doesn't generate any RFI. My experience has been
>that the degree of RFI you get from a noise source like a generator
>can be very site specific. If the antennas feedlines are adequately
>decoupled from the antennas (e.g. horizontal antennas with proper
>baluns), then the amount of pick-up may be minimal. In contrast a
>vertical antenna with an inadequately decoupled feedline may
>pick-up a lot of noise from the same source. I had this experience
>with my Honda EU2000i generator. When I checked
>at home with my horizontal antenna, I didn't hear any noise at all.
>When I went portable with the generator using the exact same
>radio, but using an R7000 vertical mounted to my trailer hitch of
>my pickup truck instead of the horizontal antenna, the switching
>noise pickup from the inverter in the Honda was S7 to S9 on 15
>and 10 meters. I used a common mode filter to get rid of this:
>
>http://www.dellroy.com/W4EF's-Ham-Radio-Page/Portable_Operation/EU2000i_Filt
>er.htm
>
>The Honda EU2000i also generates ignition noise on 160 meters.
>It was quite strong when I was using this generator in conjunction
>with my short top-loaded vertical in a portable setup. NL7Y suggested
>that I shield the spark-plug wire with copper braid between the ignition
>coil and the engine block to get rid of it. This knocked the ignition
>noise from the Honda engine down to below my local noise floor.
>
>73 de Mike, W4EF............................................
>
>
>
>----- Original Message -----
>From: "Clay Curtiss W7CE" <w7ce@curtiss.net>
>To: <rfi@contesting.com>
>Sent: Tuesday, March 22, 2005 4:29 PM
>Subject: [RFI] Honda Generator RFI
>
>
> > Does anyone have any experience with Honda generators and RFI? I just
> > purchased a Honda EM6000GP propane powered 6KW generator for use at a
>cabin
> > that is off the power grid. Unfortunately, the generator is creating a
>lot
> > of RFI. At some frequencies the noise is as high as S9+10 and at other
> > frequencies it is virtually non-existant. I don't think it is ignition
> > noise but I won't know for sure until I do some more testing. For the
>test,
> > I'll run the receiver from a 12V battery and disconnect the AC power
> > connection at the generator. If the noise disappears when I disconnect
>the
> > AC then I think I can safely assume that the noise is on the 120/240 line
> > itself.
> >
> > The cabin is wired for 240V with a standard breaker panel. I'm supplying
> > 240V from the generator to the panel. I suspect that line filters mounted
> > at the generator will probably do the trick, but I'm not sure. Any
> > recommendations? I've looked at the Corcom line filters or I could build
> > one from toroids. For the latter, I'm not sure which cores would be best.
> > I need to filter 30A at 240V.
> >
> > On a similar topic, I plan on adding batteries and an inverter so that the
> > generator doesn't need to run all the time. I've looked at the Trace
>SW4024
> > and SW5548. I like these units because they can automatically fire up the
> > generator when needed. However, they generate stepped sine wave output
>and
> > I'm concerned that I'll have the same kind of RFI that the generator is
> > producing. Would line filters help smooth out the waveforms here?
> >
> > One other option I've considered is a 6KW isolation transfomer. Would
>that
> > provide enough RF isolation at 1.8MHz and up?
> >
> > Any and all suggestions are welcome.
> >
> > Clay W7CE
> >
> >
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
>
>
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