Often, the owners of Wi-Fi transmitters face the question of how to check the signal level. Since not everyone wants to buy a device specifically for these purposes, one author came up with a solution to how to make such a device yourself. The device is very simple to manufacture and use, but its accuracy is significantly lower than specialized devices.
The idea of the device is very simple, you need to make an antenna that would receive a Wi-Fi signal and then convert it to EMF, well, and then based on the current strength, you can conclude about the signal power. As an oscillating circuit, a square of wire is used, to which a tuning capacitor is connected. As for the load, a millivoltmeter acts as it.
Materials and tools:
- microwave diode in a ceramic case (suitable D405 or D603);
- ceramic capacitor (1 nF);
- tuning capacitor (5-15 pF);
- soldering iron;
- multimeter;
- Soviet plug;
- whetted;
- copper wire;
- a piece of textolite.
Manufacturing process:
Step one. Fork preparation
To conveniently connect the device to the multimeter, the author decided to use an ordinary Soviet plug. To do this, remove its casing and then grind off all protruding parts with a sharpener. Next, you need to take two pieces of copper wire and fasten to the contacts of the plug. Between the contacts of the plug, it is necessary to solder the nanofarad capacitor.
Step Two Creating and installing an antenna
Now you need to take a piece of PCB of a suitable size and drill two holes, they are drilled approximately opposite the plug contacts. Further, previously installed copper wires are inserted into these holes. To fix the wire you need to solder to the PCB, then the design will be reliable.
Now you can start creating the antenna. One of the soldered copper wires must be separated from the common contact of the entire plate. Here will be the receiving frame. To create the framework of the antenna, you need to adhere to the drawing, all you need to bend 3 squares from the wire.The height of the first square should be 30 mm, the second 33 mm (it will act as an active vibrator). The third square will play the role of a reflector, it has a height of 34.5 mm. Of course, to achieve such accuracy is difficult, but the more accurately the squares are bent, the better the device will work. To create squares on the wire, serifs are made, and then it is bent using pliers.
After the contacts are ready, they can be soldered to the board. The most extreme squares you just need to solder to the plate itself, it is important to observe the distance. As for the central square, it needs to be soldered to the contact that was previously separated from the general conductive layer of the PCB.
Next, a microwave diode is installed on the second square, and a capacitor is soldered between the square legs. Now it remains only to solder the diode to the main plate and you can begin the tests.
Step Three Device check
To check the device you will need a phone with bluetooth. The manufactured device is inserted into the multimeter and the voltage measurement mode is turned on. When you bring the phone to the antenna, numbers should appear on the multimeter. Moving the antenna, you need to achieve the greatest voltage. Then the phone is gradually taken away, if the numbers fall, then the device is working correctly, and the frequency of 2.4 GHz has been caught.
Of course, this device is not suitable for accurate measurements, but it will not be difficult to determine approximately the strength of the signal and find its source with it. In the future, it is planned to equip the device with an additional amplifier, for example, it can be a microcontroller, which will allow more thorough analysis of the signal.