The CGC Communicator Newsletter Web Posting

From the SBE Chapter 104 List Server as Forwarded
to the CGC Communicator on September 29, 2006

Here is something Bill Ryan and Dan Neidzwicki over at WGTE encountered and shared with me.

The station receives NPR programming from Galaxy 16.  They began receiving interference from something in the 4 GHz range that would wipe out their desired feeds.  A spectrum analyzer showed the interfereing signal was 10 dB hotter than the satellite signal, and it wandered about 6 MHz up and down the band.

Some field work with a small horn antenna, LNA, and mobile analyzer led them to a condo about 1/8 mile from the studio plant, in a direction in line with the dish feed horn.  Inside the condo they found a set-top amplified TV antenna, an RCA/Thompson ANT 525, that was radiating on 4 GHz.  They convinced the owner to let them take the antenna with them for more testing.

Back at the bench, they confirmed the thing radiated on 4 GHz and drifted in the same pattern as they had already observed.  They decided to be a good neighbor and replaced the antenna with the exact same model.  Before returning to the condo, they tested it and found it radiated exactly like the first one.  In fact, they bought 3 and all 3 had radiation problems. They then purchased the next model up and it was clean.

If you encounter C Band interference, look into set-top antennas made by RCA.  That could be your problem.

Shared with Bill's permission.


Bill Rossini,CSRE
Clear Channel Toledo
419-244-8321 Voice
419-244-7631 Fax

Posted by Steve Blodgett
Earthsignals.com