DTV Reception and Consumer Antennas 2005 PBS Technology Conference Kerry W. Cozad Dielectric Communications Raymond, Maine USA

Purpose for Study Document measured performance of typical receive antennas Provide information to update “planning factors” Assist station engineers in discussions with viewers

ATSC PS/WP3 Receiver Planning Factors

Testing Methods CEA Guidelines Outdoor Range Computer Modeling

Antenna Parameters Principal plane patterns Polarization Response Azimuth Elevation Polarization Response Horizontal Vertical

Antenna Parameters Frequency Response Directivity Gain Variations within design band Response out of design band Directivity Gain

Antenna Products Tested “Set Top” Zenith Silver Sensor  Megawave Radio Shack 15-1864 loop  Terk Antenna Pro

Antenna Products Tested Attic or Outdoor RCA ANT3002 VHF/UHF Winegard PR-8800 Channel Master 4228  Winegard SS-1000 SquareShooter 

Test Range Source Antenna Antenna Under Test

Sample Test Results Typical Receive Antennas

Remember: Choose your standard carefully.

Coat Hanger UHF Patterns Azimuth Elevation

Radio Shack 1864

Radio Shack 1864 UHF Patterns Azimuth Elevation

Radio Shack 1864 VSWR 3:1 2:1

Zenith Silver Sensor

Zenith Silver Sensor UHF Patterns Azimuth Elevation

Zenith Silver Sensor VSWR 3:1 2:1

NEC Model of Zenith Silver Sensor

NEC Model of Zenith Silver Sensor AZ Pattern

NEC Model of Zenith Silver Sensor AZ Pattern

Channel Master 4228

Channel Master 4228 UHF Patterns Azimuth Elevation

Comparison of Measured to Calculated

Channel Master 4228 VSWR 3:1 2:1

Winegard Square Shooter

Spec Sheet Data Beamwidth 61° Avg. VSWR across band 1.3:1 Avg. Front to Back 13db Avg. gain across band 470-806 4.5db Max. Width Housing 16" x 16" x 4" © 2003 Winegard Company. All Rights Reserved

Winegard Square Shooter UHF Patterns Elevation Azimuth

Winegard Square Shooter VSWR 3:1

Planning Factor Review

Planning Factor for UHF: 10 dBd Gain Comparisons Planning Factor for UHF: 10 dBd

Front to Back Ratio Planning Factor: -14 dB Loop: N/A Indoor LP: -10 dB to -15 dB Outdoor Dipole Array: -17 dB to -25 dB Custom Array: -12 dB to -15 dB

What About Using Vertical Polarization? Average V-Pol/H-Pol Ratios Zenith: -20 dB Channel Master: -19 dB Radio Shack 1864: - 5 dB

Summary Indoor Antennas typically have lower gain than planning factor Use of vertical polarization is questionable when using linear array, higher gain receive antennas Reduction of multipath reception dependent on antenna design