FM: TV6 Interference Study
The FM/TV6 Interference study is designed to calculate the predicted
area of interference to the reception of TV channel 6 caused by an FM
station operating in the reserved band (channels 201-220). Calculations
are based on FCC Rules section 73.525 (e). The section below, Report
Details, details how the report is run.View
Study Sample
The customer must provide the following information to run this study:
- Job
title
- Metric
or English
- Channel
- Coordinates
- c/r
AMSL (center of radiation above mean sea level)
- ERP
- Directional
antenna (make, model, orientation)
- Polarization
(vertical=no to 6 dB television receiving antenna directivity per
Section 73.525 (e)(iii) of the FCC
Rules)
- Maximized
ERP (study calculates maximum ERP for population compliance
Price: $150.00. (Maximizer
option - $250.00, Interference Popcount - $100.00,
Plot - $100.00.
To purchase, please call
800.331.5086 or
email
info@bia.com
Report Details
First, if necessary, interpolation of ERP values is done to fill in
any portions of the pattern not supplied by the user.
Next, FM HAAT figures are generated for the eight (8) cardinal
radials. Linear interpolation is used for HAAT figures between the
cardinal radials.
Relative HAAT figures are then generated for the TV channel 6 station
selected. Since the official HAAT figure for the TV station was probably
not generated using computerized topographic data, the eight computed
HAAT figures are adjusted so that their average agrees with the HAAT
figure in the database.
The extent of the TV 6 grade B (47 dBu) is then calculated using the
FCC F(50,50) curves. If the FM transmitter site is within the TV grade B
contour, an interference area is assumed to exist and the boundaries of
the interference area will be referenced to the FM transmitter site. The
interference site will be the FM transmitter site.
If the proposed FM site is outside the TV 6 grade B contour, other
tactics are used. First, an FM interfering F950,10) contour, the value
of which is 47 + 6 plus the appropriate U/D ratio from the charts, is
computed in the direction of the TV 6 station. If this contour does not
overlap the TV grade B contour, it is assumed that no interference area
exists. If it does overlap, an interference site is selected from
which the boundaries of the interference area will be referenced.
Once it is determined that interference exists and an interference
site has been determined, the program computes the boundaries of the
interference area. Radials are computed every degree of azimuth from the
interference site to the point at which interference stops occurring.
These calculations are based on the appropriate F(50,50), F(50,10) and
FM/TV6 protection ratio curves. If enabled the field strength for
distances less than one mile, free space calculations are used. Where
appropriate, the FM/TV 6 protection ratio (U/D) figures are adjusted by
6 dB to account for receiving antenna directivity. These radials are
denoted by * on the detailed printout.
The customer must provide the following information to run this study:
- Job
title
- Metric
or English
- Channel
- Coordinates
- c/r
AMSL (center of radiation above mean sea level)
- ERP
- Directional
antenna (make, model, orientation)
- Polarization
(vertical=no to 6 dB television receiving antenna directivity per
Section 73.525 (e)(iii) of the FCC
Rules)
- Maximized
ERP (study calculates maximum ERP for population compliance
Price: $150.00. (Maximizer
option - $250.00, Interference Popcount - $100.00,
Plot - $100.00.
To purchase, please call
800.331.5086 or
email
info@bia.com
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