I spent some time at www.fair-rite.com looking at their catalog. The larger
toroids seem to only be available in type 43, 77, and 78 material. Type 31
material looks like it would be a good candidate for 160 to 6M but I only
found it used for clamp on applications on round cable (like the one on our
CRT monitor cables).
Has Fair-Rite changed their part numbering system? Their catalog doesn't
have part numbers like FT-240-43. The largest toroid I could find was
5943011101 which appears to made of type 43 material.
Clay W7CE
----- Original Message -----
From: "Dan Richardson" <k6mhe@adelphia.net>
To: <RFI@contesting.com>
Sent: Wednesday, March 23, 2005 7:39 AM
Subject: Re: [RFI] Honda Generator RFI
> 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_Fil
t
> >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
> > >
> >
> >
> >_______________________________________________
> >RFI mailing list
> >RFI@contesting.com
> >http://lists.contesting.com/mailman/listinfo/rfi
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|