Hi,
I have a review of a few RFI locating devices, and some RFI location
software, (S-Meter Lite), at:
http://nk7z.net/category/info/mitigation-of-rf-interference/
if anyone is interested...
--
Thanks,
Dave
For Amateur Radio equipment reviews and setups see:
http://www.nk7z.net
On Mon, 2013-04-22 at 21:48 -0400, Util.RFI.pro wrote:
> Just about every full feature handheld offered to the Amateur market today
> has a receiver that covers .5 to 470 MHz or 1 GHz. A 3 element yagi for 150
> MHz is easy to build (or buy). An attenuator is very helpful. Coax connects
> the yagi to the attenuator and the attenuator to the radio. This basic setup
> should be able to pinpoint a source to a pole or a house.
>
> In my opinion, the MFJ RFI searching device is only marginally useful unless
> you actually have some idea how to DF radio signals. RFI is a radio signal.
> You DF RFI much the same way you DF any signal.
>
> You need a receiver that can listen on the affected frequency in AM mode and
> has some means of showing signal strength. A directional antenna at the
> frequency of interest is very useful. A means of keeping the maximum signal
> strength indication at about midscale is required. That means the receiver
> must have an attenuator or an external attenuator must be used.
>
> Practice on known signals to develop skill. Then set out to locate the RFI.
>
> Used radios can be had for under $200. Suitable yagi antennas cost less than
> $30 in materials to build. Attenuators can be bought or made. Storebought
> attenuators can be expensive. Homemade attenuators can be cheap and
> effective. At hamfests I find all kinds of professional attenuators for $10
> and up. Coax jumpers with BNC connectors are not usually expensive.
>
> Hope this helps. Good luck.
>
> 73, Frank KB4T
>
>
> Sent from somewhere in Frank's electronic universe
>
> On Apr 21, 2013, at 10:54 PM, Gary Mayfield <gary_mayfield@hotmail.com> wrote:
>
> > Frank,
> >
> >
> > This is good to know.
> >
> >
> > Is there anything you would recommend starting with? My father is deperate
> > to find the noise in his little town. The utility has been out three
> > times, and of course each time was immediately after a rain and the noise
> > was not present. Most days it S9 or better accross the bands. The last
> > time I was down there it seemed like it was coming from all directions.
> >
> >
> > He has the MFJ handheld unit, but he hasn't had much luck with it.
> >
> >
> >
> > Thanks and 73,
> >
> > Joe
> >
> >
> >
> > > Date: Sun, 21 Apr 2013 21:18:46 -0400
> > > From: utility.rfi.pro@gmail.com
> > > To: paul@n1bug.com
> > > CC: rfi@contesting.com
> > > Subject: Re: [RFI] Ultra Sonics
> > >
> > > I have all of the Radar Engineers equipment. As a utility interference
> > > investigator I'm fortunate to have good tools. The ultrasonic unit is only
> > > useful AFTER I've already found the source pole. Even then the ultrasonic
> > > detector is able to hear the actual source only 40% of the time.
> > >
> > > The ultrasonic detector is not able to hear arcing inside a transformer or
> > > any other device where the arcing is inside a metal or plastic
> > > case/container.
> > >
> > > Frankly I could do my job just fine without the ultrasonic detector. With
> > > its low productivity and limited usefulness, my success rate would be
> > > impacted only slightly.
> > >
> > > Spend money on tools that will do the most for you. By that I mean
> > > directional indicating equipment that will pinpoint the pole, house or
> > > structure. If the source is a pole, a crew will touch everything until the
> > > source is found and corrected. If the source is in a house or other
> > > structure you will use a small receiver possibly equipped with a
> > > directional antenna to walk up to the source.
> > >
> > > Save the ultrasonic purchase for last.
> > >
> > > 73,
> > >
> > > Frank N Haas KB4T
> > > Utility RFI Investigator
> > > Florida
> > > Disclaimer: I was on the beta test team for the RX3.
> > >
> > > The RX3 is a huge improvement over the RX2. I have not tested the RX1 but
> > > looking at the schematic I suspect the RX3 would beat it by a wide margin.
> > > In tests with a controlled spark source, the stock RX2 (predecessor to the
> > > RX3) with 12 inch dish could detect the spark to a distance of 35 feet.
> > > The
> > > RX3 with the same dish could detect it at 100+ feet.
> > >
> > > I would definitely go with the larger dish. Actually I would prefer 18
> > > inch
> > > were it available. I will add that I am very disappointed in the quality
> > > of
> > > the dish, which I have communicated to the proprietor on several
> > > occasions.
> > > The detector used requires a very flat dish. Upgrading/modifying using one
> > > of the other dishes available on the market has not proven practical
> > > because they are all too deep and/or just just as poor in conforming to
> > > parabolic shape as the supplied dish. At some point when my budget allows,
> > > I plan to try a deeper/better/larger dish with a different detector (one
> > > having a wider acceptance angle or "beamwidth").
> > >
> > > Outside the scope of your question: I would NOT use ultrasonics to FIND
> > > noisy poles. You want radio receivers for that. Use the ultrasonic to
> > > verify and find specific hardware that is sparking once you have located
> > > the pole.
> > >
> > > 73
> > >
> > > --
> > > Paul Kelley, N1BUG
> > > RFI Committee chair,
> > > Piscataquis Amateur Radio Club
> > > http://www.k1pq.org
> > > ______________________________**_________________
> > > RFI mailing list
> > > RFI@contesting.com
> > > http://lists.contesting.com/**mailman/listinfo/rfi<http://lists.contesting.com/mailman/listinfo/rfi>
> > > _______________________________________________
> > > RFI mailing list
> > > RFI@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/rfi
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