View Full Version : Need help with my NBC signal (all other channels are great)
sippinhenn
18-May-2016, 11:06 PM
Here is my TV Fool report (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d513489f610e01b)
I recently installed This RCA Compact Outdoor Yagi HDTV Antenna in the attic (http://www.amazon.com/RCA-Compact-Outdoor-Yagi-Antenna/dp/B0024R4B5C?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s01) along with dropping in This COAX 50 ft coax cable down the wall to my TV. RG6 (http://www.amazon.com/Coaxial-Cable-F-Male-Connectors-Wall/dp/B003FVX8GE?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00)
All of the other major channels come in and I pick up about 35 channels. Only problem is NBC (4.1 or 48),I get the channel but it cuts in and out pretty frequently, much worse than when I had a little antenna next to the TV. Any pointers would be very helpful, thanks!
Stereocraig
19-May-2016, 8:25 AM
Attics can block more than half of the signal and reflections can cause multipath.
I would mount it outdoors and see if that improves reception.
ADTech
19-May-2016, 11:03 AM
Move the antenna and try again, the antenna happens to be in a "dead spot" for that station. Be patient and repeat as needed. It may require a movement of as little as 6 inches, 6 feet, or 6 yards or whatever it takes.
wizwor
20-May-2016, 6:51 AM
sippinhenn, there is probably not a dead spot in your attic for that one specific station given the fact that you receive others in the same direction and range. Even of your attic is contributing to multipath or attenuation, it's hard to believe that environment would single out your NBC broadcaster. 48 is the highest channel you receive. It may be that your antenna is not optimized for reception at that frequency or that you have some interference at that frequency. If the source of the interference is inside your home, moving the antenna might help. If it is a cell phone tower down the road, moving the antenna could make things worse. Maybe get a 4g/lte filter and see if that helps.
Common sources of interference include:
· Adjacent channel interference (a very strong station one channel up or down).
· Co-channel interference (two weak stations on the same channel).
· Multi-path interference (usually caused by the direct path being blocked).
· A very close transmitter (a neighborhood FM station, police station, taxi company, etc.).
· An industrial noise source (a factory, a clinic, a malfunctioning power transformer).
· Household appliances, including motors, light dimmers, and fluorescent lights.
ADTech
20-May-2016, 11:30 AM
His antenna receives that frequency just fine, there's nothing wrong with it. It's a frequency-specific "dead spot" due to an unfortunate confluence of a small signal blockage or reflection that just happens to coincide with the spot where he plopped the antenna down which just happens to coincide with the operating channel that carries his NBC affiliate. I see such issues every day, especially in attics. If you look at such an impaired signal on a spectrum analyzer as I have, the signal will have a large void somewhere in the 6 MHz bandwidth. Move the antenna and the problem moves away, or at least, somewhere else, and hopefully not into a different channel that is also occupied.
Let's not try to overthink this, go with the most logical possibility that's easy to resolve.
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