THE BIRO TECHNICAL BULLETINS 
SEPTEMBER 2009

"FREE" ON-LINE DTV RECEPTION STUDIES

A free on-line service is like romance.  When every little detail clicks, you feel like you are on top of the world.  Now and then, as your hard drive crashes, or that recently purchased remarkable iPhone works only on AT&T, the romance can easily change to a deep depression.

Getting free DTV reception information on the Internet?  It’s not all sunshine and bunnies.  Prepare yourself for a little letdown when try to use  “free” on-line DTV reception listings, such as:

ANTENNA POINT
TV FOOL
DTV.GOV

The fact is they can become criminally expensive due to missing or outdated information like RF output power and transmit antenna heights.  A faulty antenna-array/antenna-tower height recommendation may cause freezing pictures or total loss of audio.

We evaluated the above three (3) on-line DTV reception programs for the Deer Park, Alabama test site, identified by the following coordinates:

31° 10’ 02” NORTH
88° 22’ 11” WEST

ANTENNA POINT
SEARCH RESULTS

Sign Affiliate Analog Digital Band Power City Distance Heading
Total results: 25
WEIQ PBS 42 41 UHF 199.0 kW Mobile 46.09 mi 147.13°
WKRG-TV CBS 5 27 UHF 1000.0 kW Mobile 46.45 mi 142.04°
WALA-TV FOX 10 9 VHF 29.0 kW Mobile 47.56 mi 140.34°
WMAH-TV PBS 19 16 UHF 150.0 kW Biloxi 49.52 mi 230.16°
WXXV-TV FOX 25 48 UHF 300.0 kW Gulfport 55.09 mi 234.00°
WHLT CBS 22 22 UHF 140.0 kW Hattiesburg 56.48 mi 283.67°
WHBR IND 33 34 UHF 1000.0 kW Pensacola 56.59 mi 136.01°
      23   337.0 kW Mobile 57.60 mi 136.96°
WEAR-TV ABC 3 17 UHF 1000.0 kW Pensacola 57.60 mi 136.96°
WLOX ABC 13 13 UHF 14.1 kW Biloxi 57.76 mi 233.39°
WPMI-TV NBC 15 15 UHF 510.0 kW Mobile 59.24 mi 135.27°
WBPG CW 55 25 VHF 64.5 kW Gulf Shores 59.24 mi 135.27°
WSRE PBS 23 31 UHF 1000.0 kW Pensacola 59.24 mi 135.27°
WDAM-TV NBC 7 28 UHF 79.0 kW Laurel 59.45 mi 285.75°
WJTC UPN 44 45 UHF 1000.0 kW Pensacola 62.75 mi 133.82°
WMPV-TV   21 20   500.0 kW Mobile 62.75 mi 133.82°
WMAW-TV PBS 14 44 UHF 880.0 kW Meridian 78.44 mi 324.40°
WMDN CBS 24 24 UHF 956.0 kW Meridian 79.94 mi 343.88°
WGBC NBC 30 31 UHF 1000.0 kW Meridian 79.94 mi 343.88°
WTOK-TV ABC 11 11 UHF 6.15 kW Meridian 79.94 mi 343.88°
WIIQ PBS 41 19 UHF 1000.0 kW Demopolis 82.98 mi 18.06°
WFBD     48   1000.0 kW Destin 95.41 mi 98.78°
WRBJ   34 34   98.7 kW Magee 95.46 mi 311.01°
WPAN IND 53 40 UHF 33.5 kW Fort Walton Beach 96.81 mi 125.54°
WFGX   35 50   1000.0 kW Fort Walton Beach 96.81 mi 125.54°

Evaluation Results of ANTENNA POINT

  1. The program does not accept coordinates. Calculated Distances and Headings are only approximate values, not
    acceptable for a professional interference elimination analysis.
  2. With no transmit antenna height information signal levels cannot be projected.
  3. Outdated RF output power information. Channel 22, Hattiesburg and Channel 23, Mobile are authorized for much higher RF output than listed on ANTENNA POINT.
  4. Showing analog channel allocations? As of June 12, 2009, there are no more full power analog TV stations in the US.

Compare the ANTENNA POINT readout with Biro Engineering’s Computer Run, prepared for the same location. Enjoy a complete, up-to-date, well organized listing of all received DTV stations in a 70 mile radius, presented in increasing distance orde, including all essential technical parameters.

*** COMPUTER AIDED TV RECEPTION STUDY ***

BIRO ENGINEERING
PRINCETON, NEW JERSEY

SITE: Deer Park, Al.
COORDINATES: 31/10/02 88/22/11
DIST
CHAN
CALL
LOCATION
STATE
NETWK
DTV
POWER
OFST
HAAT
AZIMUTH
LEVEL
POLAR
MILES
            
kW
  
FT
DEGS
dBmV
  
44.41
16
WMAH
BILOXI
MS.
ED
X
150.0
0
1565.
230.3
-2.5
H
45.05
41
WEIQ
MOBILE
AL.
ED
X
199.0
0
607.
141.0
-5.9
H
46.30
27
WKRG
MOBILE
AL.
CBS
X
1000.0
0
1637.
136.2
4.5
H
47.33
9
WALA
MOBILE
AL.
FOX
X
29.0
0
1250.
134.2
-4.0
H
47.34
25
WBPG
GULF SHORES
AL.
WBN
X
1000.0
0
1158.
134.2
4.5
H
50.06
48
WXXV
GULFPORT
MS.
FOX
X
300.0
0
1496.
234.7
-2.7
H
52.59
13
WLOX
BILOXI
MS.
ABC
X
11.0
0
1301.
234.5
-9.8
H
53.75
22
WHLT
HATTIESBURG
MS.
CBS
X
1000.0
0
800.
288.1
-2.6
H
57.48
28
WDAM
LAUREL
MS.
NBC
X
79.0
0
420.
290.3
-28.9
H
57.51
34
WHBR
PENSACOLA
FL.
REL
X
1000.0
0
1362.
131.6
2.2
H
57.53
17
WEAR
PENSACOLA
FL.
ABC
X
1000.0
0
1900.
131.6
3.4
H
57.53
50
WFGX
FT. WALTON BCH.
FL.
IND
X
1000.0
0
1910.
131.6
1.2
H
59.28
31
WSRE
PENSACOLA
FL.
ED
X
1000.0
0
1739.
130.2
2.1
H
59.28
15
WPMI
MOBILE
AL.
NBC
X
1000.0
0
1847.
130.2
3.3
H
59.41
23
WDPM
MOBILE
AL.
REL
X
435.0
0
1751.
130.1
-0.9
H
62.71
20
WMPV
MOBILE
AL.
TBN
X
500.0
0
1736.
129.4
-06
H
62.77
45
WJTC
PENSACOLA
FL.
UPN
X
1000.0
0
1499.
129.4
-1.0
H

The  next evaluated “free” service, DTV.GOV was found practically useless for the CATV head-end engineer.

Evaluation Results for DTV.Gov

  1. The program does not accept site coordinates.
  2. The stations are identified by their old, analog channel allocations.
  3. Signal legends characterize signal levels only as “Strong”, “Moderate”, or “Weak”.  That may satisfy a rooftop antenna installater, but is unacceptable for quality CATV engineering purposes.
  4. No RF output power or transmit antenna height information is included.

TV Fool was the third “free” program, evaluated by Biro Engineering.  The results are presented below:

TV FOOL
TV SIGNAL ANALYSIS RESULTS
DEER PARK, AL

The listing is better quality, but still has many shortcomings.

  1. The test location cannot be identified by coordinates.
  2. RF output power and transmit antenna height data are missing.
  3. Directions (Azimuth Angles) are incorrect.
  4. Signal level projections in dBm may please the microwave engineer, but in
    the CATV industry we use dBmV.

CATV ENGINEERS NEED MORE INFORMATION

True, DTV Reception Studies are all about information.  However, CATV head-end engineers need more technical assistance.  They have to prepare the system for:

The FCC sold off the top 100 MHz of the UHF band for $20 billion, forcing Channel 52 to Channel 68 stations to relocate into the 470 to 700 MHz frequency range.  When you squeeze a lot of TV stations into a limited frequency range, you are looking for trouble.  The net result: an increasing number of co-channel and adjacent channel interference conflicts.

The Biro DTV Reception Studies probe for co-channel interference possibilities channel by channel, and when required, develop precise and complete co-channel interference information, composed of a Signal Direction Sheet and tabulation of co-channel offenders in a 250 mile radius.

CHAN CALL LOCATION
STATE
NTWK
DTV
POL
POWER
OFST
HAAT
DIST
AZIMUTH
kw
FEET
DEGS
DESIRED STATION                   
31 WSRE PENSACOLA
FL.
ED
X
H
1000.0
0
1739.
 59.28 MI 130.2
CO-CHANNEL CALCULATION                  Rel Ang CC Space
31 WGBC MERIDIAN
MS.
NBC
X
H
828.0
0
542.
 82.33 MI 143.4 H =17.3
31 WLAE NEW ORLEANS
LA.
ED
X
H
200.0
0
899.
 124.67 MI 327.1 3H = 31.3
31 WLGA OPELKA
AL.
UPN
X
H
4.0
0
482.
 161.23 MI 159.5 3H = 31.4

Experiencing co-channel interference? When searching for the co-channel offender with the aid of a search antenna there is no reason to work blind. With the Biro Co-Channel Signal Direction Sheet you have all essential information at your fingertips, reducing testing (search) time and achieving positive interference source identifications.

And, an Antenna Bill of Materials and Computer Aided Tower Design are an integral part of every Biro DTV Reception Study.

If you don’t mind the broken heart the “free” studies will give you in the form of incomplete, poorly organized and selective information, by all means, take the plunge. However, if you are in the market for more than a fling, and are looking for a comprehensive, better organized interference elimination information, including a phased antenna-array design – choose your partner carefully.

For emergency engineering services:
Call: (609) 883-9866
E-mail: steven@biroengineering.com
Web site: www.biroengineering.com

Biro Engineering
P.O.BOX 2175
PRINCETON, N.J. 08543