[RFI] RFI Digest, Vol 115, Issue 23.....identification or rfi

[Dave Cole]

Hi,

Where did you find the dish?  I have a 12 inch one, and want to go
larger...
-- 
Thanks,
Dave
http://www.nk7z.net for equipment reviews, propagation, and more...
For JT65 Discussions:
https://groups.google.com/forum/?fromgroups#!forum/jt65


On Fri, 2012-08-24 at 13:42 -0500, stbradford wrote:
> Hello Dave,
> 
> I have spent a couple of years cleaning up rfi with the local power
> company. The ARRL and the company were very helpful in resolving many
> faults.
> 
> Your noise is the product of a discharge on the power grid. It's at
> 120 cycles because both the positive and negative sides of the ac are
> arcing somewhere.
> I use an 3 element yagi tuned to 135 mhz with a 40db attenuator that
> can be inserted into the antenna line. When you get close the receiver
> can be overloaded, so the pad was needed. 
> 
> Most of the problems here in southern Indiana turned out to be loose
> hardware and a few incorrect bell insulator installations. Once the
> rfi gets on the power line you have a jim dandy antenna. But with the
> 40db pad I can stand between two poles, but not in line with them, and
> see which direction the signal is coming from. You kind of form a
> triangle with you at the top and the poles at the bottom angles.
> 
> I went of the deep end and made an 40 khz acoustic detector using a
> 19" parabolic dish to spot the actual arc location. RFI really sounds
> of at 40 khz. But you must be near to the noise. I would stand back
> from the pole and scan the hardware with the acoustic detector, it
> will get you very close to the problem area.
> 
> Dave, I have attached a few photo's of the equipment I built. Both are
> in the ARRL archives. The antenna article by Jim Hanson I think. The
> ultrasonic detector
> author has slipped my mind. I expect the reflector to strip the
> photo's so is someone else wants the photo's drop me a line.
> 
> Smith Bradford
> W9HAK
> 
> 
> 
> 
> 
> 
> 
> 
> On 8/24/2012 11:00 AM, rfi-request at contesting.com wrote:
> 
> > Send RFI mailing list submissions to
> > 	rfi at contesting.com
> > 
> > To subscribe or unsubscribe via the World Wide Web, visit
> > 	http://lists.contesting.com/mailman/listinfo/rfi
> > or, via email, send a message with subject or body 'help' to
> > 	rfi-request at contesting.com
> > 
> > You can reach the person managing the list at
> > 	rfi-owner at contesting.com
> > 
> > When replying, please edit your Subject line so it is more specific
> > than "Re: Contents of RFI digest..."
> > 
> > 
> > Today's Topics:
> > 
> >    1. Can someone ID this source of RFI? (Dave Cole)
> >    2. professional question (K1TTT)
> >    3. Waveforms of RFI... (Dave Cole)
> > 
> > 
> > _______________________________________________
> > RFI mailing list
> > RFI at contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> > 
> > 
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.2197 / Virus Database: 2437/5220 - Release Date: 08/23/12
>