Sennheiser A 3700 Omnidirectional Antenna with Booster - 502195

Product Overview

The Sennheiser A 3700 is an active omnidirectional UHF antenna with an integrated booster, designed specifically for use with Sennheiser EM 3731, EM 3732, and EM 3732 Command rackmount receivers. It provides up to 15 dB of selectable amplification to compensate for signal loss incurred over long BNC coaxial cable runs between the antenna and the receiver rack. The A 3700 covers 470–866 MHz and is ideal for installations where the antenna must be positioned remotely from the equipment rack — such as at the front of a stage, on a lighting truss, or in a distributed antenna system. An LED indicator confirms active status, and the unit accepts both 3/8" and 5/8" thread mounts for standard microphone stand or boom arm deployment.

Product Description

When Sennheiser EM 3731 or EM 3732 receivers are rack-mounted at a distance from the performance or speaking area, long coaxial cable runs introduce signal attenuation that can degrade RF sensitivity and increase dropout risk. The A 3700 solves this by placing an active amplifier stage at the antenna itself, boosting the signal before it travels down the cable. Gain is field-selectable at four settings: bypass (−3 dB), +5 dB, +10 dB, and +15 dB, allowing technicians to dial in the appropriate compensation for the specific cable run length and installation layout. Without remote power supply, the passive loss is −6 dB, so active operation via the 9–15 V DC remote power supply (delivered over the BNC coaxial cable from the receiver) is essential for installations exceeding short cable runs. The antenna's omnidirectional polar pattern provides 360° coverage in the horizontal plane, making antenna aiming unnecessary and simplifying placement in venues with performers moving across the stage. The wide frequency range (470–866 MHz) covers the operating bands of the entire EM 3731/3732 receiver family. At 50-ohm impedance with an OIP3 of ≥32 dBm, the A 3700 maintains linearity under high RF density conditions, minimizing intermodulation distortion in multi-channel wireless environments. The unit's flat, paddle form factor (9.84" x 6.49" x 0.90") is lightweight at 13.75 oz and mounts easily on a standard microphone stand via the included 3/8" or 5/8" thread adapter. A single BNC connector handles both RF signal and DC power delivery from the compatible receiver.

Key Features

• Integrated Booster with Selectable Gain — Four gain settings (bypass/−3 dB, +5 dB, +10 dB, +15 dB) compensate for coaxial cable run loss in remote antenna installations.
• Wide Frequency Coverage (470–866 MHz) — Spans the full operating range of Sennheiser EM 3731, EM 3732, and EM 3732 Command receivers.
• Omnidirectional Polar Pattern — 360° horizontal coverage eliminates the need for precise antenna aiming; ideal for dynamic stage environments.
• 50-Ohm Impedance, OIP3 ≥32 dBm — High linearity maintains signal integrity in dense multi-channel RF environments, minimizing intermodulation products.
• Single BNC Connection — One cable carries both RF signal and DC power from the receiver, simplifying installation and reducing cable runs.
• DC Remote Power via BNC — Powered at 9–15 V DC / 160–100 mA over the coaxial cable from the connected receiver; no separate power cable required at the antenna.
• LED Status Indicator — Visual confirmation that the antenna is receiving power and operating in active mode.
• Dual Thread Mount (3/8" and 5/8") — Compatible with standard microphone stand threads for flexible placement on any stage or stand position.
• Lightweight Paddle Design — At 13.75 oz (390 g) and 9.84" x 6.49" x 0.90", the A 3700 is unobtrusive and easy to position in sight lines or on stage infrastructure.

Typical Applications

• Remote antenna placement for Sennheiser EM 3731 / EM 3732 receivers racked at the front-of-house or in a back-of-house equipment room
• Distributed antenna systems (DAS) in large venues where antennas must be placed at multiple coverage points distant from receiver racks
• Houses of worship with receiver racks in AV closets and antennas positioned near the sanctuary floor or stage
• Theater and performing arts installations requiring remote antenna placement at the stage edge or pit position
• Conference centers and ballrooms with long cable runs from the equipment room to coverage zones
• Touring productions using EM 3731/3732 systems that require a compact, mount-anywhere antenna solution

Technical Specifications

Frequently Asked Questions

Q: Which Sennheiser receivers is the A 3700 compatible with?

The A 3700 is designed for use with the Sennheiser EM 3731, EM 3732, and EM 3732 Command receivers. It is not cross-compatible with other Sennheiser receiver families such as the EM 300-500 G4 series, which uses a different remote power specification.

Q: How is the A 3700 powered?

The A 3700 receives DC power remotely over the BNC coaxial cable from the connected receiver (9–15 V DC at 160–100 mA). No separate power supply or cable is required at the antenna location. Without remote power, the antenna operates passively at −6 dB.

Q: How much gain does the A 3700 provide?

The integrated booster offers four selectable gain settings: bypass (−3 dB), +5 dB, +10 dB, and +15 dB. The appropriate setting depends on the length of the BNC cable run and the signal level requirements of the installation.

Q: What is the maximum recommended cable run length?

The maximum usable cable length depends on the cable type and the gain setting selected. Higher gain settings compensate for longer runs. RG-8 or equivalent low-loss 50-ohm coaxial cable is recommended for longer installations. Consult Sennheiser's installation guidelines for specific run-length recommendations based on cable type and gain selection.

Q: Does the omnidirectional pattern mean I do not need to aim the antenna?

Correct. The A 3700's omnidirectional polar pattern provides 360° horizontal coverage, so precise directional aiming is not required. Simply position it in a clear line-of-sight location relative to the wireless transmitters operating in the coverage area.

Q: Can I use two A 3700 antennas in an antenna combiner setup?

The A 3700 is designed for direct connection to a single receiver or compatible antenna distribution/combining system. Verify compatibility with your specific antenna combiner or splitter before deployment in a multi-receiver distributed system.

Q: What mounting options does the A 3700 provide?

The A 3700 includes both 3/8" and 5/8" thread mount options, which are compatible with standard microphone stands and boom arms. This allows flexible placement at stage-edge positions, on lighting or rigging infrastructure, or on any standard stand in the venue.