BSN NAL Portable Magnetic Mount Antenna (SYN7391-A (w/SMA))

BSN NAL Portable Magnetic Mount Antenna (SYN7391-A (w/SMA))

In reseller catalogs, the part number is typically presented as SYN7391-A (w/SMA) and described as a black magnetic mount antenna with an SMA connector variant. The antenna family is also widely sold under NAL Research accessory listings (SYN7391-A), reflecting its use across multiple Iridium handset and modem ecosystems.

Design and Features

Magnetic-mount base for rapid deployment

SYN7391-A is built around a magnetic mounting base intended for fast placement on ferromagnetic surfaces. This approach allows users to reposition the antenna for best sky view or to move it between vehicles without tools. Some product descriptions explicitly highlight its suitability for quick installation “on or inside automobiles.”

Low-profile patch antenna construction

The antenna is commonly described as a pocket-sized passive L-band antenna with a low profile suitable for unobtrusive placement. Published dimensions for SYN7391-A are approximately 1.81 in (L) × 1.71 in (W) × 0.45 in (H).

SMA connector variant with integrated cable

The (w/SMA) designation indicates the SMA connector variant. A common published configuration specifies an SMA male connector with an integrated 36-inch (≈0.9 m) cable.
(Some related “portable auxiliary antenna” variants in the broader SYN7391 family are sold with TNC connectors and longer leads; those are typically separate SKUs and should not be assumed interchangeable without adapters.)

Materials intended for field use

One published specification set lists plastic construction with a hard-anodized base, consistent with rugged portable accessories designed to be repeatedly mounted and removed.

Technology and Specifications

Frequency band (Iridium L-band)

SYN7391-A is specified for Iridium’s L-band uplink/downlink window, commonly listed as 1616 to 1626.5 MHz.
This is the operational range used by Iridium voice and data services, making the antenna relevant for Iridium handsets, SBD modems, and compact tracking terminals that use SMA RF ports (with appropriate adapters where required).

Electrical characteristics

Published specifications for SYN7391-A include:

• VSWR: less than 1.5:1

• Axial ratio: 2 dB
  These parameters are commonly used to indicate impedance match quality (VSWR) and polarization quality (axial ratio), both of which influence real-world satellite link performance—especially in marginal signal environments.

Environmental and mechanical durability

A published specification set lists:

• Operating temperature: –40°F to +185°F (≈ –40°C to +85°C)

• Operating altitude: 20,000 ft

• Vibration tolerance: > 30 G’s
  These figures position the antenna for vehicle, outdoor, and industrial deployments, where temperature swings and vibration can be significant.

Ground-plane guidance

Because the antenna is typically used on a metal surface, placement is often described in terms of a “ground plane.” One published spec lists a minimum ground plane of 2 inches from all edges, which in practice means placing the antenna on a sufficiently large metal surface (or using a dedicated metal plate) to achieve stable radiation characteristics.

Applications and Use Cases

Vehicle-based Iridium use (temporary or multi-vehicle)

A core use case is improving Iridium connectivity while driving or operating from a vehicle, especially when the handset or modem is inside the cabin. The magnetic mount makes it practical to move the antenna between vehicles or to deploy it only when needed.

Portable “go kits” and emergency communications

Emergency response kits and field “go bags” sometimes include a magnetic mount antenna as a lightweight way to improve signal acquisition at a staging site, command post, or remote location—particularly when users can place it on a vehicle roof, metal case, or temporary plate.

Temporary fixed-site setups

For temporary site offices, remote projects, and short-term installations, a passive magnetic antenna can be used as a quick alternative to a permanently mounted antenna and cabling run—useful for short deployments or evaluation/testing.

Advantages / Benefits

Fast installation without drilling

The magnetic mount supports rapid deployment and repositioning without tools, a key advantage over fixed brackets when installations are temporary or frequently moved.

Better sky view and reduced indoor attenuation

Placing the antenna outside (or near a window on a suitable metal surface) can significantly reduce signal loss caused by building materials, vehicle roofs, or equipment enclosures.

Compact, passive design

As a passive antenna with an integrated cable, SYN7391-A avoids external power injectors and simplifies field logistics—particularly for short cable runs typical of portable use.

FAQ Section 

What is the BSN NAL Portable Magnetic Mount Antenna (SYN7391-A (w/SMA))?

It is a compact Iridium L-band passive external antenna with a magnetic mount and an SMA connector variant, used to improve satellite connectivity by placing the antenna on a suitable metal surface.

How does SYN7391-A (w/SMA) work?

The antenna receives and transmits Iridium L-band signals (around 1616–1626.5 MHz) and is positioned externally (often on a vehicle roof) to improve sky visibility and reduce signal loss compared with using an indoor or obstructed antenna.

Why is SYN7391-A (w/SMA) important?

In many real deployments, Iridium performance is limited by poor antenna placement (indoors, under metal roofs, or inside equipment enclosures). A portable magnetic antenna provides a fast way to improve placement and link reliability without permanent installation.

What are the benefits of SYN7391-A (w/SMA)?

Common benefits include tool-free magnetic mounting, compact size, passive (no-power) operation, and published electrical characteristics such as low VSWR and 2 dB axial ratio in one specification set.

What surface do I need for the magnetic mount antenna?

The antenna is typically intended to be placed on a sufficiently large metal surface (“ground plane”). One published spec recommends a minimum ground plane of 2 inches from all edges, which can be satisfied by many vehicle roofs or a dedicated metal plate.

Summary

The BSN NAL SYN7391-A (w/SMA) is a portable, passive Iridium L-band magnetic mount antenna designed for quick deployment and improved satellite signal reliability in vehicles and temporary field setups. With published specifications covering compact dimensions, Iridium-band coverage, low VSWR, and wide operating temperature range, it is commonly used as a practical accessory when users need better antenna placement without committing to permanent mounts or long cable runs.