Simple Field Strength Meter Circuit

A simple field strength meter circuit is presented in this article, let's learn more about it's construction details.
For a radio receiver, it is often a pain to evaluate the strength of the field on which the performance of the radio is dependent.

The circuit used for this purpose is a cost effective yet useful tool to achieve performance evaluation of the radio field strength.

The extreme left of the circuit is the crystal receiver or crystal radio part of the circuit. A suitable germanium diode like the IN34 or AA119 is recommended.

A silicon diode does not achieve the performance of a germanium diode for its functions as a varactor because of its depletion layer characteristic.

The inductance can be built by 6 to 8 turns of enameled wire having a diameter of 1milimeter and a coil diameter of millimeter.

The capacitor selected is around 100picoFarrad that resonate with inductance. By adjusting the spacing of the turns, the frequency can be varied.

The second stage of the circuit employs a high impedance amplifier in the style of a JFET 2N3819 that is gated by a variable 470K resistance.

This is basically a potentiometer. By adjusting this, the sensitivity of the circuit is adjusted. This trimmer is used for achieving 0 deflection in the meter.

It is recommended to use meters of 50miliAmpere or lesser capacity.

While calibrating with different antennae, this meter is very useful. However, great performance from such a simple circuit with a cheap meter is not expected.

Comments

TDA2030 complete tone control

At this time I present a series of amplifiers that use IC TDA2030, but this series is equipped with a tone control. Tone controls include Bass, Treebel, and Volume. Power amplifier and tone control has been put together in a single PCB. As well as its power supply circuit was also used as one with the power amp, and tone control. Making it easier in the installation and will look neat. Schematics Layout PCB PCB design This amplifier is a mono amplifier type, can be modif for guitar amplifiers. If not coupled amplifier (mic preamp) then you must deactivated potensio treble and bass, why? because if not using a mic preamp and still maintain potensio treble and bass sound input (input) from the guitar will not or the maximum discharge is not tight on the speakers. So you must deactivated a way to decide which directly connected capacitor with the tone control circuit, and capacitor were connected directly to potensio volume and input jack.

PID instruction in Allen Bradley PLC Closed Loop Control

PID instruction in Allen Bradley PLC [Proportional/Integral/Derivative] Closed Loop Control For Processor SLC 5/02SLC 5/03SLC 5/04SLC 5/05 MicroLogix 1200 and MicroLogix 1500 (A special PID file replaces the old integer file control block.) Description of PID in PLC This output instruction is used to control physical properties such as temperature, pressure, liquid level, or flow rate of process loops. The PID instruction normally controls a closed loop using inputs from an analog input module and providing an output to an analog output module as a response to effectively hold a process variable at a desired set point. The PID equation controls the process by sending an output signal to the actuator. The greater the error between the setpoint and the process variable input, the greater the output signal, and vice versa. An additional value (feed forward or bias) can be added to the control output as an offset. The result of the PID calculation (control vari...

NE566 Function Generator Circuit Diagram

The NE566 Function Generator is a Voltage-Controlled Oscillator of exceptional linearity with buf fered square wave and triangle wave outputs. The frequency of oscillation is determined by an external resistor and capacitor and the voltage applied to the control terminal. The Oscillator CAN be programmed over a ten-to-one frequency range by proper selection of an external resistance and modulated over a ten-to-one range by the control voltage, with exceptional linearity. FMAX = 1 MHz WIDE 1000:1 Continuous Sweep Possible NE566 Function Generator Circuit Diagram Pdf Datasheet Sourced by : Circuitsstream

Mutchus

Search This Blog