The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: firstname.lastname@example.org (milne_v)
Subject: Re: Why is the home voltage so high ?
Date: 3 Oct 2002 19:13:38 -0700
NNTP-Posting-Date: 4 Oct 2002 02:13:38 GMT
True enough, the point of the radio is because they are portable and
you can easily determine if the RFI is local to your home and/or
elsewhere like next door for example. If its local to your home but
not 20 feet away from your home or even at the next door neighbors
home, then there has to be a reason. Unless your running x-ray
equipment or a TIG welder at your place. If the neighbor is running
this type of equipment then the RFI should be coming from his place
not yours, right? Consequently the AM radio interferance should get
worse as you approach his place not your place. If you use your radio
with a known source of RFI like a TV set you can determine how the
radio is directional. After doing that you can easily use the portable
AM for local radio direction finding and walk right up to any local
sources of RFI. No-one is going to be using a portable x-ray machine
in their homes, are they? and microwave cell towers won't be picked up
on the AM radio. You also have to be fairly close to a TV set to get
action as well.
"News2020" wrote in message news:...
> Thanks for the detailed post.
> I believe you might be on the right track. I have been observing this over a
> 'long' period of time and have come to the same type of conclusions.
> However, I do not have access to scopes and RF meters at the moment. How
> could a radio be conclusive ? It does show chatter between stations, but
> that could be anything, not necessarily proof of power line modulations (?).
> There are lots of gizmos nowadays that are being used for video, audio,
> cellular, satellite, infrared-remotes, locally-broadcast-dvds, etc. In
> addition, due to the present climate of suspicion/alerts/etc, I believe
> there are lots of equipment being field tested. You must have heard news of
> Xray scanners and such being manufactured in large quantities, etc.
> Similarly, many others things (microwave, towers, transmitters, etc.) seem
> to be happening without much fanfare outside public reviews.
> "milne_v" wrote in message
> > "News2020" wrote in message
> > > I measured the voltage at the power outlets at home and found it to be
> > > to 140 V.
> > >
> > > This is way beyond the expected range (110-120) ?
> > Do you have access to a scope? If yes then scope the mains, use a step
> > down transformer if you don't feel comfortable working at mains
> > voltages.
> > Look for narrow spiked transients on mains sinewave. Could be at zero
> > crossing, could be elsewhere. If they are there, then these transients
> > can easily be the source of many of your problems. Make sure that
> > triac dimmers and inductive motor alliances in the home are off at the
> > time. If you find transients then move on to the homes grounding
> > system and scope a grounded metallic structure using an external
> > ground stake as a grounded referance. If transients also appear on the
> > homes grounded structures, then you have identified at least part of
> > your problem. Don't confuse the transients with power line
> > frequencies. They will produce very broad band RF. If they appear on
> > grounded structures with triacs and motors shut off then I doubt
> > whether the source is within the home. These transients can and will
> > produce nasty resonant harmonics in operating appliances. Should they
> > appear on grounded structures then you can assume that whatever is
> > producing them is not a toy. It's probably a high powered source in or
> > around your home that encorporates some type of high powered arc
> > discharge or some high powered line switching device. You can also use
> > a computer with sound card, a program such as "cool edit" and some
> > shielded cable with the appropriate plugs to record the grounded
> > structures signals with no danger and then analyze the waveform
> > looking for the same type of thing. Should these transients be present
> > then it's safe to say that they don't belong there. Should transients
> > be present then they will probably produce RFI harmonics that are
> > easily picked up on the lower end of a portable AM radio. If you get
> > as far as finding the RFI on the radio, then use the radio to check
> > for sources in and around your home such as your hydro meter and
> > neighbouring hydro meters. This can be used to determine if the
> > problem is specific to your neighbourhood or specific to your home.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup