[CQ-Contest] [RFI] ATT U-verse Service RFI Issues

Jim Brown jim at audiosystemsgroup.com
Sun Jul 29 15:36:06 EDT 2007


On Sun, 29 Jul 2007 14:34:27 EDT, PaulKB8N at aol.com wrote:

>He told me  that those fittings have been very problematic for not
>maintaining a good ground  connection, 

Paul,

Thanks for recounting your experience. It's input like this that 
can save a lot of us a lot of trouble, and help others figure out 
what's going on in another system.

One important correction. It is not the GROUND connection that was 
problematic, it was the connection of the CABLE SHIELD. To be 
effective, shielding must be CONTINUOUS, but there is NO 
requirement for a connection to GROUND. Didja ever see a 747 
trailing a GROUND wire? :)

Your last problem (the lockup after you changed channels) appears 
to have been the result of nothing more than LEAKAGE TO the cable 
system due to that bad connection. I'll bet that the bad connection 
was also leaking trash TO your ham receiver! 

To understand why the DXE #31 clamp-ons were not effective (they 
are very good parts), study my tutorial on RFI. First study the 
first couple of chapters, then make sure you read the section on 
the Threshold Effect.

http://audiosystemsgroup.com/RFI-Ham.pdf

73,

Jim Brown K9YC





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