Sensitive-field-strength-meter


Posted on Jun 16, 2012

The two-pole, five-position switch, coils and 365-pF variable capacitor cover a range from 1.5 to 30 MHz. The amplifier uses Darlington npn transistors whose high beta, 5000, provides high sensitivity with Sl used as the amplifier on/off switch. Switch S2 in the left position allows the output of the 1N34 diode to be fed directly into the 50-,u meter (M) for direct reading. When S2 is in the right position, the amplifier is switched into the circuit.


Sensitive-field-strength-meter
Click here to download the full size of the above Circuit.

Switch S3 is for local or remote monitoring. At full gain setting, the input signal is adjusted to give a full-scale reading of 50 mA on the meter. Then with the amplifier switched out of the circuit, the meter reading drops down to about 0.5 mA. A 2.5-mH rf choke and capacitors C3, C4, and C5 effectively keep rf out of the amplifier circuit.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    LED Voltage indicator
    Three-channel tone control
    arduino How can I display a scoreboard on stage for a play
    ESR-Meter
    btr200
    Dtmf Generator At90s4414
    Spunky Tube Amplifier
    LM386 voice audio power amplifier circuit design project
    Light Dark switch activated relay circuits
    Joulethief SEC exciter and variants 64
    Current Limiting for Redundant Power Systems
    ISO122P / 124 power supply has a three-port isolation amplifier circuit diagram
    Solid state relay circuit controls the motor-way operation



    Top