RF Interference
03-25-00, 07:16 AM
#1
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Location: Wichita, KS, USA
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RF Interference.
For about four years I have been trying to track down what might be causing
interference in my home entertainment and phone system and ever so often I
get so frustrated that I post in a newsgroup to see if I might get a lead on
how to track down {with proof if outside of my home!} what might be causing
this interference.
THE EFFECTS:
I have this 'BUZZ' that is in 'BOTH' of my phone lines 'IF' the phones
are corded phones (can not be heard on the cordless phones!). Some days can
almost hear voices in the phone in the southwest corner of my home.
[b] Can be seen as large white specks on VHF channels 3 & 12 and as a 'white
and black' line moving slowly from the bottom to the top of the screen on
UHF channels 27 & 29 that I create in my home with a consumer grade home
modulator. (Sony MRDD1 made by ChannelPlus)
<C> Some days I can pick-up a local FM station that broadcasts in the 80's
on VHF channel 4.
<D> There are some areas of the home where you can not use a 900mhz cordless
phone that is no where near home electronics. Like at the front door.
<E> I get a 'HUM' from two different power strips in two different rooms on
two different breakers.(changed strips <brand and style>, and devices
plugged in) the power LED would at times 'FLASH' with no device plugged in!
<F> I have this little 'Soothing Sounds' electronic sleep aid [work 3rd
shift, helps mask traffic noise] that 'HUMS' when no sound is chosen... the
worse the 'EFFECTS' on the other devices are the louder the 'HUM'.
<1> When it snows the interference goes away!!
<2> The interference goes away sometime when it rains very heavy!!
<3> The interference seems to be least between the hours of 7am till noon.
<4> The interference seems to be the worse between the hours of 6pm till
6am. peaking around 10pm.
I have had both KG&E and SWB out, but wouldn't you know it when the service
techs show up the interference goes away!! [only during the day time]
Using the 'soothing sounds' box found that the 'HUM' is in the power line
ONLY goes two house to the west and one house to the east and the houses to
the north and south are on different transformers and do not have the 'HUM'
KG&E did scope some 'strange' sine wave in my power line one day, but when
they moved to the pole the wave was gone. And a hand held RF signal tracker
did not pick up anything?!?
Any ideas or know of any devices that I might be able to rent (cheaply) that
can help me track this interference down?!?
I have tried a number of different consumer grade traps, both RF and AC, to
try to trap out the interference with no luck.
David E. Carmichael
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For about four years I have been trying to track down what might be causing
interference in my home entertainment and phone system and ever so often I
get so frustrated that I post in a newsgroup to see if I might get a lead on
how to track down {with proof if outside of my home!} what might be causing
this interference.
THE EFFECTS:
I have this 'BUZZ' that is in 'BOTH' of my phone lines 'IF' the phones
are corded phones (can not be heard on the cordless phones!). Some days can
almost hear voices in the phone in the southwest corner of my home.
[b] Can be seen as large white specks on VHF channels 3 & 12 and as a 'white
and black' line moving slowly from the bottom to the top of the screen on
UHF channels 27 & 29 that I create in my home with a consumer grade home
modulator. (Sony MRDD1 made by ChannelPlus)
<C> Some days I can pick-up a local FM station that broadcasts in the 80's
on VHF channel 4.
<D> There are some areas of the home where you can not use a 900mhz cordless
phone that is no where near home electronics. Like at the front door.
<E> I get a 'HUM' from two different power strips in two different rooms on
two different breakers.(changed strips <brand and style>, and devices
plugged in) the power LED would at times 'FLASH' with no device plugged in!
<F> I have this little 'Soothing Sounds' electronic sleep aid [work 3rd
shift, helps mask traffic noise] that 'HUMS' when no sound is chosen... the
worse the 'EFFECTS' on the other devices are the louder the 'HUM'.
<1> When it snows the interference goes away!!
<2> The interference goes away sometime when it rains very heavy!!
<3> The interference seems to be least between the hours of 7am till noon.
<4> The interference seems to be the worse between the hours of 6pm till
6am. peaking around 10pm.
I have had both KG&E and SWB out, but wouldn't you know it when the service
techs show up the interference goes away!! [only during the day time]
Using the 'soothing sounds' box found that the 'HUM' is in the power line
ONLY goes two house to the west and one house to the east and the houses to
the north and south are on different transformers and do not have the 'HUM'
KG&E did scope some 'strange' sine wave in my power line one day, but when
they moved to the pole the wave was gone. And a hand held RF signal tracker
did not pick up anything?!?
Any ideas or know of any devices that I might be able to rent (cheaply) that
can help me track this interference down?!?
I have tried a number of different consumer grade traps, both RF and AC, to
try to trap out the interference with no luck.
David E. Carmichael
================================================
National 'Onebox.Com' Internet Services: (Dallas, TX, USA)
mailto: [email protected]
Voicemail / Fax to Internet: (512) 682-6997 ext. 1096
================================================
V3 URL Redirect Services [ for more info: http://www.go.to ]
home page: http://welcome.to/1608alta
================================================
Southwestern Bell Internet Services:
mailto: [email protected] Home Page: http://home.swbell.net/dec2955/index.html
================================================
Southwestern Bell Telephone (Services Wichita, KS, USA)
Local Voice: (316) 524-0246 Local Voicemail / Fax: (316) 524-9731
================================================
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03-25-00, 11:10 AM
#2
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Join Date: Mar 2000
Location: Stevens Point, Wi, USA
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I had a similiar problem a whiel back and
it turned out to be my line doubler power
supply leaking and causing RF interference.
Have you tried disconnecting the equipment
1 at a time? Also, don't count out bad power
cords or flourescant light fixtures. In
extreme case you may need an isolated ground
circuit for power. I am not sure what the
exact term is but they use an orange outlet.
They are highly recommended to protect high
end equipment. I do not have this but was
told by installers that I should. I have had
technicians from power companies and phone
companies in my house over the years looking
for leaks and am not impressed with their
knowledge. If there is a reputable A/V installer in your area they could probable
isolate the problem for you. It their area
of expertese. I mean from a high end store-
not Best But, etc.
it turned out to be my line doubler power
supply leaking and causing RF interference.
Have you tried disconnecting the equipment
1 at a time? Also, don't count out bad power
cords or flourescant light fixtures. In
extreme case you may need an isolated ground
circuit for power. I am not sure what the
exact term is but they use an orange outlet.
They are highly recommended to protect high
end equipment. I do not have this but was
told by installers that I should. I have had
technicians from power companies and phone
companies in my house over the years looking
for leaks and am not impressed with their
knowledge. If there is a reputable A/V installer in your area they could probable
isolate the problem for you. It their area
of expertese. I mean from a high end store-
not Best But, etc.
