Installing Iridium External Antenna

Some Spider installations require an external antenna that can provide GPS and Iridium communication.

Spidertracks have tested Sensor system's S67-1575-109 antenna.

The S67-1575-109 is a low-profile, wide-band Iridium antenna providing continuous coverage from 1565 MHz to 1626.5 MHz for excellent Iridium coverage as well as GPS L1 applications. Spherical-radius molded radome features enhanced protection against rain, ice and lightning strikes. The antenna is hermetically-sealed and DC-grounded. 

Antenna Installation Information

The Iridium antenna must be mounted on top of the aircraft for the greatest satellite visibility. For best performance, select a location with an unobstructed view of the sky, above the aircraft when in level flight and as close to the centerline of the aircraft as possible, and not to exceed an offset ± 5° max.

The antenna should be mounted in a location that would provide at least 8° horizontal view of the horizon and minimise blockage from the vertical stabiliser or other obstructions. Typically, antenna manufacturers recommend a minimum separation of 24" or greater from any other antenna regardless of system type.

The recommended spacing between the external antenna of the Spider and other antennas is a minimum separation of 24".

Using an External Antenna With Spider X Model

When connecting the external antenna to the Spider X, please make sure you are using correct antenna port for the antenna type. 

1. External Cell Antenna

2. External Iridium Antenna

Also see this article on how to enable the external antennas for the Spider X.

Using an External Antenna With Spider 7 & 8 Models

The following diagram shows how to connect the Iridium antenna. 

 

Other Antennas:

If you are not using the S67-1575-109 antenna, other antennas need to meet the following specification requirements:

• Passive antenna able to receive L1 GPS signal on 1575.42 MHz
• Able to transmit L-band frequencies between 1616.0 - 1624.5 MHz
• Is ideally tuned as close to these frequencies as possible (bandwidth)
• VSWR is less than 2:1
• Has 50-ohm impedance
• A radiation pattern that is hemispherical (i.e. it points to the sky in all directions)
• Polarisation is right-hand for both Iridium and GPS.

FAQ

Q. I want to use a simple Coaxial Cable for the antenna, will this work?

A. There should be no more than 2dB of loss between the two components, including insertions. Antenna cable should be RG-178 or similar. 

In the case where a cable of significant length is required, it may be necessary to use a higher grade.

Q. Does the antenna require an STC in order to be installed?

A. This depends on your Civil Aviation authorities. In the USA the installation can be done via a Technical Standard Order, using the FAA 337 form.

If you are having problems updating please contact [e-mail]