Beads over antenna cables and line cords only blocks common mode signals. RF
can still flow thru line cords and into the house wiring or thru the coax
into other equipment.
Many years ago Doug DeMaw had a QST article on a brute force line filter
that actually works well. Ive built several inside outlet strips and plug
all sorts of offending equipment into them.
I also use ferrite beads but not the snap on type which are 43 mix and
fairly useless at low frequencies. A mixture of 77 and 43 mix beads that
just slip over RG-6 work best for me followed by a good HPF on TV's, VCR's,
DVD's etc.
Line cords get wrapped on a 33 mix ferrite rod or you can use a 77 mix
FT-240 size toroid.
If the TV is radiating through a plastic cabinet you can line the inside
with aluminum foil or spray on a conductive coating.
Since I operate from 1.8 MHz thru 10 GHz I sorta got obsessive about RFI in
both directions. It takes some time, effort and money to do it all.
Carl
KM1H
----- Original Message -----
From: "Jim Wilhite" <[EMAIL PROTECTED]>
To: "Discussion of AM Radio in the Amateur Service"
<[email protected]>
Sent: Sunday, December 02, 2007 4:12 PM
Subject: Re: [AMRadio] Part 15 Devices
Yea I have read it Bob. And given the attitude of the FCC I really don't
think they would take any action. The first answer is always, "Move
something". I sure would like the FCC to get back into non-interference
and enforcement.
Jim/W5JO
I have haerd that the new flat screen TVs are the worst offeners. The
FCC's
solution is to have the owner of the device stop using it.
Have you tried reading Part 15?
Bob Macklin
K5MYJ
Seattle, Wa,
"Real Radios Glow in the Dark"
----- Original Message -----
From: "Jim Wilhite" <[EMAIL PROTECTED]>
To: "Discussion of AM Radio in the Amateur Service"
<[email protected]>
Sent: Sunday, December 02, 2007 12:35 PM
Subject: Re: [AMRadio] Part 15 Devices
Well guys I put snap beads around the power cord (about 6 of them as I
recall) and still hear it on several frequencies in the 75 meter band.
It radiates as much as 50 ft. away and I don't think they should have
that much.
On top of that, the frequencies move when the state changes from off to
on. Like all of you my house if full of these devices. My HP computer
doesn't do this, my Canon multi-purpose printer doesn't do this, none of
the kitchen appliances do it, the DVD player doesn't and neither does my
electronic thermostat. All of which I can take a portable receiver and
go near and hear them on the same frequencies with the TV unplugged.
One leg of my 75 meter antenna is about 50 ft. away and the TV causes
spurs that can be heard that far away. I know it isn't the satellite
box and not the answering machine adjacent to it. Everything clears
when I unplug the TV. It is the first TV I have ever had that radiates
this much.
Jim/W5JO
> How do you know it is out of compliance? There are measured radiation
> limits. Every one of the new entertainment devises that has a remote
> controller have a microprocessor that runs all the time unless the
> device is
> unpluged. You can get radiation off the cables. unplug all the cables
> and
> see what you get.
______________________________________________________________
Our Main Website: http://www.amfone.net
AMRadio mailing list
List Rules (must read!): http://w5ami.net/amradiofaq.html
List Home: http://mailman.qth.net/mailman/listinfo/amradio
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:[email protected]
To unsubscribe, send an email to [EMAIL PROTECTED] with
the word unsubscribe in the message body.
______________________________________________________________
Our Main Website: http://www.amfone.net
AMRadio mailing list
List Rules (must read!): http://w5ami.net/amradiofaq.html
List Home: http://mailman.qth.net/mailman/listinfo/amradio
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:[email protected]
To unsubscribe, send an email to [EMAIL PROTECTED] with
the word unsubscribe in the message body.
______________________________________________________________
Our Main Website: http://www.amfone.net
AMRadio mailing list
List Rules (must read!): http://w5ami.net/amradiofaq.html
List Home: http://mailman.qth.net/mailman/listinfo/amradio
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:[email protected]
To unsubscribe, send an email to [EMAIL PROTECTED] with
the word unsubscribe in the message body.
______________________________________________________________
Our Main Website: http://www.amfone.net
AMRadio mailing list
List Rules (must read!): http://w5ami.net/amradiofaq.html
List Home: http://mailman.qth.net/mailman/listinfo/amradio
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:[email protected]
To unsubscribe, send an email to [EMAIL PROTECTED] with
the word unsubscribe in the message body.
