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NGS-C170-SBL Series
UHF Broadband Slot Antennas with Enhanced Front to Back Ratio for NextGen Single Frequency Networks. Low Wind-load, Elliptically or Circularly Polarized.


The NGS-SBL (Suppressed Back Lobe) series antennas are ideal for multi-channel Next Generation TV networks. These antennas are designed to reduce radiation in the rear direction to minimize interference to adjacent services. For difficult network planning scenarios, these antennas will enable the network designer to meet the FCC requirements without resorting to large reductions in radiated power.
The high-power rating and broadband performance allow multiple channels to be transmitted from an SFN site, thus reducing capital costs and providing consistent coverage across channels. Elliptical or circular polarization is available for improved transmission to portable and indoor devices. 
The NGS-SBL family of antennas provide both top-mounted and side-mounted solutions in a low wind load format. 
A wide range of radiation patterns are available. The RFS Antenna Selection Tool contains pattern data for all NGS antenna models and works alongside modern SFN planning tools to help you choose the right NextGen antenna for each SFN site.  To download, click Here


  • Reduced rear radiation (suppressed back-lobe design) simplifies network planning for difficult sites reducing the need for large ERP reductions to mitigate interference.
  • Broadband performance for multi-channel SFN networks allows SFN infrastructure sharing and reduces overall CAPEX.
  • Low wind-load reduces tower loads thus simplifying SFN site acquisition.
  • Large range of azimuth radiation patterns – simplifies the SFN planning process to provide optimum network coverage. 
  • Broadband elliptical or circular polarization performance – improves signal penetration and network performance.
  • Supplied with brackets for side mounting to a wide range of tower leg sizes.



Product Type   NextGen-TV Broadcast Antenna

Electrical Specifications 

Antenna Type   Broadband Slot Antenna with Enhanced Front/Back Ratio
Operating Frequency Range MHz 470-608
Polarization   Elliptical
Azimuth Radiation Pattern   Cardioid C170-SBL
VSWR   <1.1:1
Impedance Ohms  50 (for 1-5/8" to 6-1/8" Inputs)
 75 (for 7-3/16" Input)

Mechanical Specifications 

Radome Diameter mm (in) 381 (15)
Pressurization Operational kPa (psi) 10 to 25 (1.4-3.6)
Pressurization Test kPa (psi) 100 (15)


Material - Radome   UV Resistant Fibre Glass
Material - Insulators   Virgin PTFE
Material - Support Pole / Mounting   Hot Dipped Galvanized Steel
Material - Feedline & Radiators   Copper
Material - Reflecting System   Aluminum
Color   White, others on request

Model Number Specifications 

Antenna Model   NGS08-C170-SBL NGS12-C170-SBL NGS16-C170-SBL NGS20-C170-SBL NGS24-C170-SBL
Number of Bays   8 12 16 20 24
Elevation Gain at 539 MHz Numerical 8.4 12.1 16.0 20.1 24.0
Azimuth Pattern Directivity Numerical 2.0
Peak Gain at 539 MHz Numerical 16.7 24.2 31.9 40.2 48.0
Peak Gain at 539 MHz dBd 12.2 13.8 15.0 16.0 16.8
Standard Beam-Tilt [note 1] 1.0 1.0 0.75 0.75 0.75
Power Rating: High Power Model kW 34 50 60 70 80
Connector: High Power Model   4-1/16" 6-1/8" EIA 6-1/8" EIA 6-1/8" EIA 7-3/16"
Power Rating: Low power Model kW 10 15 20 25 30
Connector: Low Power Model   3-1/8" EIA 3-1/8" EIA 3-1/8" EIA 4-1/16"  4-1/16" 
Mounting Type   Top or Side Top or Side Side Side Side
Height m (ft) [note2] 4.30 (14.1) 6.49 (21.3) 8.69 (28.5) 10.91 (35.8) 13.11 (43.0)
Weight kg (lb) [note2] 238 (525) 445 (981) 621 (1370) 804 (1773) 1050 (2315)
Effective Area Front (No Ice)

m2 (ft2)
[note 2,3,4]

1.00 (10.8) 1.51 (16.2) 2.01 (21.7) 2.52 (27.1) 3.02 (32.5)

External Document Links

Antenna Selection Tool: Download


Note 1: Other Beam-tilts available on request

Note 2: Data shown is for side mounted antennas 

Note 3: Design Parameters in accordance with TIA-222-G are:

  • 160 kmh (100 mph) Basic Wind Speed with no ice
  • Structure Class II
  • Topographic category 1, Exposure category C
  • Interface steelwork to tower not included in calculations.

Note 4: Moment of arm from mounting pole to centre of antenna = 0.65m (2.1ft).