[RFI] CATV Upstream Interference

[Jim Brown]

On Thu, 27 Aug 2009 04:15:10 -0700 (PDT), Luciano Nachif wrote:

>Am I right when I say those few places where I hear the 29.207 
>signals are the strongest ones so they actually are the leaking 
>spots?

Yes. And the most likely cause is a bad connection of the coaxial 
cable shield. These connectors are crimped onto the cable, and 
it's easy to have a bad connection if the worker is careless, or 
if the wrong crimp tool is used, or if the crimp connector does 
not match the cable (each cable type requires a slightly different 
connector based on small differences in cable diameters and shield 
type). 

BUT -- another common cause of leakage is an illegal connection 
made in homes by someone who doesn't want to pay the cable 
company. 

Another tip for locating the leakage points -- take a VHF talkie 
and look for the trash next to the cable. Before you start 
walking, listen to the cable on the talkie and tune in some 
signals that you know are coming from the cable. Then put the 
cable back together and listen for that signal next to a cable 
splice that you suspect may be bad. 

In general, the higher in frequency that you are able to chase a 
broadband radiated source, the closer you will be able to "home 
in" on it. 

There are a few guys on email lists that I read (maybe this one) 
who have recent experience with CATV, and may have more advice for 
you.

73,

Jim Brown K9YC