How to Filter the RF Output for GPS L1 & L2 Receivers

An RF filter antenna can help to prevent interference from local radio transmissions.

Global positioning system (GPS) receivers come in a wide variety of formats, from those that are mounted and integrated into cars and phones to dedicated handheld devices. A problem faced by every variety of GPS receiver, however, is reception problems due to interference from radio signals operating around the same frequency as the L1 and L2 GPS frequencies in a user's particular vicinity. Fortunately, there are special antennas that are manufactured for the purpose of filtering out radio frequencies, and installing them is a fairly straightforward process.

Things You'll Need

• Screwdriver
• RF filter antenna compatible with your GPS unit

Instructions

1. Open your GPS device to expose the wiring and receiver.

2. Mount your RF filter antenna, using the supplied screws. Most handheld and car-mounted GPS devices will have a filter box adjacent to the receiver where you can mount a compatible antenna.

3. Connect the exposed wiring of the antenna to the indicated terminals on the filter box.

4. Reassemble your GPS device and turn it on to ensure that it is working properly.

Tips & Warnings

• Modifying your GPS device may void its warranty. Consult your individual model's documentation for more information.

• Do not touch the receiver with your screwdriver when you are mounting your antenna. You may damage it and render it inaccurate or inoperable.

References

• Antennas.us; UFL-1575-338, GPS Antenna Filter