Many of us face poor 3G connectivity. A homemade antenna for a 3G modem is one of the ways out of the situation. And it’s not so important whether you have a connector for it in your device or not, because we will offer you a solution for such equipment where it is, as well as for one in which it is not.
The antenna for the modem is capable of amplifying a weak signal. Let's start with the easiest way to make it. The copper wire is taken, and about three to four turns are made around your device. It’s best to do them at its very tip, as there is a built-in receive antenna.
For the test, we took a modem that showed -107 decibels. When winding copper wire, the so-called “palmer” indicator increased, while the reception indicators increased to -101 decibels. This antenna for a DIY 3G modem requires clear action. After all, you yourself have to choose the length, thickness, and also the number of turns of wire. For example, an extra length or turn can both improve and degrade the quality of signal reception.
Antenna for the modem: option two. It is called a colander or pan. All lovers of experiments, which were driven to despair by the low speed of access, invent various exotic designs in the image of a pan, screens, and satellite dish. This option is slightly better than the previous one, however, such an antenna for the modem will require much more time.
It is worth noting that the extension cable is often included with the device. Its length, as a rule, is from three to five meters. At the end there is a small piece of double-sided tape, with which the modem is mounted near a window or on a wall. Instructions are also provided by the device manufacturer. In action, such an antenna for a modem is similar to the wire version, which we considered at the very beginning.
The next method is canned. At first it was often used on WI-FI networks. Thanks to this method, craftsmen were able to stretch these networks a distance of several kilometers between access points. So, we take an empty can and we make simple calculations.
Here is an example of such a calculation. The diameter of the can (D) is one hundred millimeters. The wavelength L o is equal to 143 millimeters, respectively, L o / 4 will be approximately 36 millimeters. The wavelength L g is 261 millimeters, and L g / 4 will be approximately 65 millimeters. Therefore, at a distance of 65 millimeters from the bottom of our cans, we make a hole in which we fix the standard socket. A waveguide is soldered to it, the length of which is 36 millimeters. It should be made of copper wire, the diameter of which is two millimeters.
Now we take a braided cable for television, an antenna connector is attached to it, which is inserted into the bank, and on the other hand, a modem connector.
And if it does not have a connector? In this case, you can disassemble the device and find the measuring socket on the board itself. A shielded wire of small diameter is soldered to it. Thus, you will output the adapter to connect the antenna to it. But you need to do this very carefully so as not to lose the modem’s warranty or not to disable it completely.