The Spider 7 / 8 external antenna requires an antenna that can provide GPS and Iridium communication.
Spider Tracks Limited has tested the antenna S67-1575-109 manufactured by Sensor systems, however there are several antennas in the market that could work with the Spider, as long as these have a single input, dual channel antenna for Iridium and GPS connectivity.
Also, the antenna needs to meet the following requirements:
• Passive antenna able to receive L1 GPS signal on 1575.42 MHz; and,
• Able to transmit L-band frequencies between 1616.0 - 1624.5 MHz; and,
• Is ideally tuned as close to these frequencies as possible (bandwidth); and,
• VSWR is less than 2:1; and,
• Has 50 ohm impedance; and,
• 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.
Antenna Installation Examples
Q. My Spider 7 External is not showing up on the Spidertracks website - Why?
This could be for a number of reasons;
1. Have you checked the specifications of the antenna you are using to what we recommend?
2.- Is the external antenna installed in a recommended position?
3. Have you used the cables provided with the Spider? Please note that there should be no more than 2dB of losses 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 requires an STC in order to be installed?
A. This really depends on your Civil Aviation authorities. In the USA the installation can be done via a Technical Standard Order, using the FAA 337 form.
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. What is the recommended spacing between the external antenna of the Spider and other antennas installed in the aircraft?
A. As a general guideline, the Iridium antenna should be mounted on top of the fuselage, as close to the centerline of the aircraft as possible, 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 minimising 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.