The Sirio CX-4-83 is a 4m band base antenna, this one is designed to work between 83 and 88MHz.

Features:

- Base station antenna, Mono-band
- Low-gain, Omnidirectional
- Protection from static discharges DC-Ground
- Made of aluminium alloy 6063 T-832
 

 Electrical Data
- Type: 3/4λ coaxial J-pole
- Frequency range:
 CX 4-68: tunable 68...73 MHz
 CX 4-73: tunable 73...78 MHz
 CX 4-78: tunable 78...83 MHz
 CX 4-83: tunable 83...88 MHz
- Impedance: 50Ω
- Radiation (H-plane): 360° omnidirectional
- Radiation (E-plane): beamwidth @ -3 dB = 60°
- Radiation angle: 3°
- Polarization: linear vertical
- Gain: 2dBd - 4.15 dBi
- Bandwidth @ SWR ≤1.5:
 CX 4-68: ≥ 1.7 MHz @ 68 MHz
 CX 4-73: ≥ 2.0 MHz @ 73 MHz
 CX 4-78: ≥ 2.5 MHz @ 78 MHz
 CX 4-83: ≥ 2.5 MHz @ 83 MHz
- SWR. @ res. freq.: ≤ 1.2
- Max. Power (CW) @ 30°C: 500 Watts
- Grounding protection: All metal parts are DC-grounded, the inner conductor shows a DC short
- Connector: UHF-female
   
Mechanical Data
- Materials: Aluminium, Brass, Stainless Steel, Nylon
- Wind load / resistance: 97 N @ 150 Km/h / 150 Km/h
- Wind surface: 0.08 m²
- Height (approx.): from 2700 to 3360 mm
- Weight (approx.): 1900 gr
- Mounting mast: Ø 35-42 mm