ARDCKM-A-7177 Omnidirectional Dipole Antenna 71-77 MHz - Protel Antennas - Professional Antennas for Telecomunications

The ARDCKM-A-7177 is an omnidirectional broadband dipole antenna for the 71–77 MHz VHF band with 6 MHz bandwidth and typical gain of about 4.1 dBi. It is suitable for professional VHF networks, public-safety and emergency communications (fire brigades, police, ambulance and civil defence radio), as well as utility, energy and industrial radio systems that require a 360° azimuth pattern and linear V/H ±45° polarisation.

According to the technical data, the ARDCKM-A-7177 operates from 71 to 77 MHz with 6 MHz bandwidth, typical gain of about 4.1 dBi (slightly variable with distance from the pole), return loss ≥ -14 dB, VSWR ≤ 1.5:1 and 50 ohm nominal impedance. The antenna supports V/H ±45° linear polarisation and provides typical -3 dB beamwidths of about 190° in the H-plane and 90° in the E-plane. Maximum RF power is 500 W with N-female connector and 1 kW with 7/16-female connector. All metal parts are DC grounded for lightning protection.

The datasheet specifies the broadcast band reaction in the 87.5–108 MHz FM band: approximately -3 dB at 87.5 MHz, -10 dB at 100 MHz and -12 dB at 108 MHz. These values help system designers evaluate how the antenna behaves with nearby FM broadcast signals when the main service uses the 71–77 MHz band, for example in shared sites or multi-service installations.

The ARDCKM-A-7177 has approximate dimensions of 1900 x 1000 x 40 mm and a weight of about 5 kg including clamp. The wind surface is around 0.05 m² front and 0.08 m² side, with wind loads of about 5.3 kg (front) and 8.1 kg (side) at 180 km/h. Mounting is suitable for masts with Ø 40–114 mm. Materials include stainless steel 316 for radiator and support, Teflon, brass, aluminium and stainless-steel nuts and bolts, with a hot-dip galvanised clamp. Accessories include the RAD5087 polyvinyl chloride radome; packaging is approximately 2000 x 180 x 180 mm with a total weight of about 6 kg including clamp.