It is a nifty piece of technology, this is the best way to describe GPS antenna and how it operates. The first GPS technology requirement so they will work properly is to have a clear view of the sky. This is crucial because it is a qualified satellite-based technology, and this implies that if there are too many atmospheric obstructions present in your area, it may get in the way of the satellite signal and a thick volume of clouds are among the possible and most complained about obstructions here.
Therefore, the odds that your handheld unit will not work in case your car roof is blocking signal reception is high. If you are among those hundreds of people who are unfortunately experiencing this kind or similar issues, the best course of action you have here is to add up an external antenna instead.
By crack open your GPS, you’d be able to extend the wire between the internal and its dedicated antenna. However, the signal’s tendency here is to degrade a little due to the use of the extra wire.
To get past this signal loss brought about by extra wiring, active antennas can be put into good use to amplify the signal. With some smart hacking skills, you can make use of an external active antenna to almost every kind of GPS unit.
To carry out this project, you will need for the following:
- GPS receiver
- 26 gauge wire, or about 0.4mm level of thickness
- 47pf or 100pF ceramic capacitor
- The active GPS antenna, external kind
- BNC mounting panel connector
- Minijacks, about 1/8 inch size or similar for serial output and power (optional)
- Tools to have: Pliers, wire strippers, soldering iron, and drill
What we are trying to have here is no less than a low cost GPS receiver that you can mount anywhere in the guts of our vehicle.
How Does It Work?
Satellites are made to orbit the earth so they can transmit radio signals back to us. The purpose of GPS antennas is to receive that signal, which active antennas would amplify a little bit, and then send it down the receiver line.
The power injector performs what it is supposed to carry out, and that transmits power to the cable antenna then up to the antenna itself. The signal will be transmitted to the GPS receiver. With regard to the time and the satellites, the receiver is being to “see” its position on the earth calculated.
Building the Coil
A piece of 26 gauge wire is needed to make a coil. To give you an idea, that is about 0.400 thick. You can pull apart an 18 gauge stranded wire, this should be of help to you in getting to the right size. The digital caliper will oscillate between 0.39 to 0.40.
Make the coil by wounding your 26 gauge wire around your 3.32-inch drill, about 6 complete turns. It’s pretty easy to just wind it, squash and then finally you will try to separate them evenly with the use of your fingernails only.
Case Modding
You can mount the hardware to the inner linings of a, say, penguin mint tin. Start by drilling a large hole, and this will be intended for the BNC connector. Begin with a small drill bit, then you can eventually work your way up in size.
Building
It is pretty easy to finish up the job. With the help of a few lines of hot glue will provide for you a simple insulator that will help prevent shorting of your board on the bottom part of the tin. The coil will have to be linked to your GPS board power pin. As for the capacitor, it should run to the coax signal line to the board. The shielding should be soldered to the BNC connector’s outer tab. There is an ample amount of space for this in the BNC connector. If you are not so keen on cracking open your shiny GPS, the alternative option you have here is re-radiating antenna.