[RFI] TV RFI better info

Hardy Landskov n7rt at cox.net
Mon Jan 28 22:36:23 EST 2008


With an Inv Vee at 40 ft, all of your other electronics are in the near
field of your antenna.
Let me share a couple of experiences:

 I was in a 2nd story apartment once with an antenna on the (flat) roof and
I got into
every Hi Fi system in the building. There was so much RF close to the
affected equipment that moving was the solution.

Later, I had a VCR that caused TVI problems when it was turned on or OFF.
Seems there was some circuit that was resonant in the 80 meter band and fed
into the TV. I site paragraph two of your email. No amount of bypassing,
ferrite chokes, etc would get rid of the problem. You either watched TV or
did the radio.

Since TV sound is FM, it sound like RF is getting into the audio section of
the TV (regardless of channel) and getting rectified. There again, no
shielding of the TV (plastic case) allows RF to enter.

I finally got a 100 ft tower 50 ft away from the house. End of problems.


At 07:37 PM 1/28/2008 -0800, rrath at charter.net wrote:
>Several of you have asked me to give more info. Here it is.
>I have the Yaesu FT 100, coax (not flat line) and the apex of the inverted V 
>is about 40' and both ends are at about 9'. All radio equipment is gounded
>a 12" long pc of copper pipe under my desk top. I am using 12 gauge 
>stranded wire to the copper pipe. I am using 8 gauge solid copper to one 8' 
>ground rod about 7' away, then the same pc of 8 gauge wire continues on 
>about 5' more to a 4' ground. 
>I have some TVI with out the amp on. The type of TVI is nothing to the 
>picture and blaring distortion on the sound. This is with or with out the
>turned on. The radio output is at 70 watts out.
>Now with the amp turned on and running between 300 to 400 watts SSB, the 
>sound is just as bad and the picture had very bad horizontal lines.
>I have cable TV, no Digital, the TV is about 5 years old, has two built in 
>speakers (but I think it is only mono sound - have no control for left or
>on the speakers) and the VCR is less than 1 year old. I am using 75 ohm 
>coax for all connections. I use no cable box. 
>Need more info?
>ps - K9YC, I am reading your web site. Thank you.
>RFI mailing list
>RFI at contesting.com

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