[VHFcontesting] CATV RFI from 2m SSB (UPDATE)

Lee Scott - AA1YN aa1yn at aa1yn.com
Tue Feb 15 23:53:20 EST 2005

At 10:22 PM 2/15/2005 -0600, DUGAS, JASON A. (JSC-EP) (NASA) wrote:
>Well this afternoon, I did some more investigating.  Here are the results...
>I called my neighbor to verify exactly what type of interference he was
>getting.  He said that ONLY THE AUDIO was being affected.  Said he had a
>perfect video signal.
>However, in the process of investigating further, on the way home from work,
>I tuned my FT-100D in the truck to 145.25MHz and as soon as I got with in
>spitting distance of my neighborhood, I heard the carrier on FM along with a
>nice little hum.   Tune up to 145.35MHz or so and the noise is all but gone.
>Got home and powered up my weak signal setup and the TS-850 w/ DEMI
>transverter says the noise (on SSB) is right around 145.249Mhz.


The frequency 145.25 is the video carrier frequency for channel 18. ALL 
cable providers (and I did capatilize "ALL") must maintain their cables to 
the point of NO LEAKAGE.  This requirement is not due to ham frequencies 
nor our interference to the cable but due to cable using aircraft 
frequencies.  They are very diligent about leakage.  If you give them a 
call and let them know you found cable leakage in your area, they will be 
out usually within 24 hours.  By the way, I would give them a call this 
evening as they maintain 7X24 support hotlines and the sooner the leakage 
can be investigated, the better off you are.

Interesting to note, if a large leakage is found, they are required by law 
to report the incedent to the FCC. Also, annually, they are required to do 
a complete survey of their network for leakage.  The frequency they rely on 
is 139.25MHz for their survey.  If you can report to them that you are 
detecting leakage on this frequency, you might even get faster response.

Lee Scott - AA1YN http://www.aa1yn.com
Home of the VHF & Up Register http://www.aa1yn.com/vhf
Home of the VHF Talk chatroom http://vhftalk.aa1yn.com
Hooksett, NH

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