jb_ky said:
Always thought there would be some type of interference with the channels being so close and on the same tower. 39/40 and one with more power than the other. I assume because one antenna is on top of the tower and the other is on the side.
Seemed to think WLEX and WTVQ used the same antenna.
The main reasons to think such are:
The FCC lists the heights:
WLEX:
Antenna Height Above Average Terrain: 286. meters HAAT
Antenna Height Above Mean Sea Level: 578.3 meters AMSL
Antenna Height Above Ground Level: 273.3 meters AGL
WTVQ:
Antenna Height Above Average Terrain: 284. meters HAAT
Antenna Height Above Mean Sea Level: 578.3 meters AMSL
Antenna Height Above Ground Level: 273.3 meters AGL
The antenna model is the same for both:
Antenna Make: DIE Antenna Model: TFU-30DSC-R 3S180DC
and, the directional patterns are the same (shown at FCC site).
Puzzled about the 2 meters difference in HAAT?
A WTVQ technical exhibit states that the number was corrected to 284 meters, maybe the WLEX version did not get the correction?
WTVQ doc shows a side mounted antenna for DTV, this would agree with the directional pattern.
A top mounted antenna is shown on the same tower drawing.
Looking at earlier FCC doc, shows a top mounted antenna was used for NTSC.
Maybe the top-mounted antenna is no longer in use?
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Digital TV (8VSB) seems to cause much less of adjacent channel interference that did NTSC. Here in Dallas there are a number of stations located adjacent channel.
If one adjacent channel has several dB more signal strength than another (not sure of the exact number, but more than 10dB difference) then the weaker channel can be disrupted in the receiver.
There are some FCC requirements that adjacent channel towers(serving the same area) be located near each other and to have some power output constraints relative to each other.