Passive antenna systems

What is a passive antenna?

  1. It consists of two (or three) aerials connected with a low-loss co-axial cable.

  1. This passive repeater is positioned at a point where the reception is optimum from the extreme ends.

  2. Antennas do not amplify the signal; but only relay it to cover a blind spot.

  3. Position can be determined using the three-person reception test.

  4. The maximum cable length we recommend is 50m for UHF and 100m for VHF communication.

What is a three-person reception test?

  1. This is done by placing two people with hand portables at extreme ends of the location while a third person acts as a repeater.

  1. The third person tries to position himself in the middle at the most appropriate location where reception is good from both ends.

  2. Once this position is determined you can consider placing the passive antennas at that point.

Part numbers (please ask your Dealer or Entel Account Manager for prices):

  1. CAT2004 – VHF Folded Dipole Antenna complete with N sockets

  1. CAT2006  – UHF Folded Dipole Antenna complete with N sockets

  2. LD-103 – Westflex 103 Cable

  3. PlugNWF – N Type Plug for Westflex 103 Cable

  4. NT3WFMF – 3 way splitter

  5. SOCKETNWF – Socket for 3-way splitter

Diagram of passive antenna systems:

Specifications:

MECHANICAL SPECIFICATION

Connection

RG213/U Coaxial Cable c/w N socket

Construction

Aluminium Alloy Tube 6063T6 to BS 1474

Fasteners

Stainless Steel Grade A2-70 to BS6105

Saddle Clamp

Diecast Zinc Alloy

Protection

Direct Grounded

Insulator

Epoxy Resin Encapsulant

Mounting Clamp

Crossover Clamp (not included)

Down Lead

3 m

Elements

12.7 mm X 1.6 mm Wall

Support Boom

31.7 mm X 2.6 mm Wall

Weight

80 MHz

160 MHz

450 MHz

2.6 kg

2.3 kg

1.9 kg

Boom Length

80 MHz

160 MHz

450 MHz

1.3 m

1.0 m

1.0 m

Wind Loading @ 45 m/s

80 MHz

160 MHz

450 MHz

134N        
101N              
66N

 

ELECTRICAL SPECIFICATION

Frequency Range

68 - 470 MHz

Impedance

50 Ohms

Bandwidth

22%

Polarisation

Vertical

Typical Gain

1.5 dBd

Front To Back Ratio

4 dB

H Plane Beamwidth

200

E Plane Beamwidth

85

VSWR

<1.5:1

Maximum Power

150W