Published description of the device that would indicidual the presence of microwave radiation range. It can be used to check the efficiency of the transmitter cell phone, etc.
Unlike previously described in the magazine "Radio" similar device (Radiation detector cell phone), the proposed indicator has a significantly longer range (up to 10 m.
Diagram of the device shown in Fig. 1. Reception is conducted on a broadband half-wave antenna consisting of two vibrators W1 and W2.
The device is made according to the scheme of the receiver of direct amplification and contains a radio frequency amplifier (RF amplifier), a detector and an audio indicator. The signal induced in the receiving antenna, amplified UHF and arrives at the detector. Proyektirovanii signal opens the electronic key, assembled on the transistor VT2, and he, in turn, includes an audible signaling device HA1 - the bell will ring..
With the help of indicator we can determine the modes of operation of the cellular phone. When the cell phone enters the network, the indicator starts beeping, and when you call someone and in conversation with him, the alarm will sound continuously.
Most parts are placed on a circuit Board from a two-sided foil fiberglass, a sketch of which is shown in Fig. 2.
View of the assembled indicator without housing shown in Fig. 3.
The finished Board is placed in a plastic housing, which is pre-set variable resistor R4 (Fig. 4).
Adjust the indicator by connecting a fresh battery according to the standard technique. Then check the performance indicator and the detection range of the signal, activating a cell phone.
Literature
Author: I. Nechaev (UA3WIA), Kursk; Publication: www.cxem.net