The amplification can be adjusted by p1 and with s1 switch we can select three frequency ranges. Adjust c1 for peak reading.
The circuit use only one transistor mpsa18 as the active component.
Field strength meter schematic. Here is the schematic diagram of this rf strength meter circuit. This field strength meter uses an 1ma fsd ammeter dc and indicates the radio magnetic field strength between 0 to 1ma scale range. To use turn on transmitter and meter.
C1 c3 0 01 µf capacitors rs 272 1051 or equiv. This project answers that age old question is anything radiating from this antenna. Rf field strength meter the field strength meter is simple effective and easy to construct.
7056 railway ave courtenay bc v9j 1n4 canada. This circuit can be used to detect magnetic field strength of radio signal and common radio transmitting signal through antenna. This circuit is another radio frequency rf field strength meter similar with our previous field strength meter circuit but with lower supply voltage only a single cell 1 5v battery.
Here is the schematic diagram of this rf meter circuit. This circuit help us to. L1 480 khz to 2 4 mhz l2 2 4 mhz to 12 mhz l3 12 mhz to 40 mhz the antenna is made of 30 cm long metal rod.
This rf field strength meter has no absolute scale if we don t calibrate the scale using a standard instrument but the important thing for this. The capacitor c3 and inductor l1 forms a tuned circuit to receive a particular frequency the frequency of your transmitter the diode d1 detects the signal and applies to the base of transistor q1 mpsa 18 the collector current of the q1 will be proportional to the strength of this signal and will be shown in the meter m1 in result the meter. Simple field strength meter circuit diagram.
The rf field strength meter circuit schematic. Considering these factors a dual mosfet is used as an rf amplifier in this circuit. Here is a very useful project schematic of a sensitive field strength meter circuit.
Set the meter to zero by adjusting p1 before you turn on the transmitter. Field strength meter this portable 90 db dynamic range rf field strength meter is simple to build. A field strength meter is an instrument that measures the electric field strength emanating from a transmitter.
A field strength meter is actually a simple receiver. The signal strength meter display uses analog meter 1 ma full scale. Simple field strength meter circuit is designed by using single transistor and few easily available components.
With the bridge out of balance currents flows to the meter through r3 the meter and the emitter collector junction of the transistor. The circuit shown here can be used as a wide band field strength meter and can. Figure 1 schematic diagram of the signal strength meter.
A field strength meter fsm is a very useful circuit to detect and measure the rf signals and their strength. After a tuner circuit the signal is detected and fed to a micro ammeter or in this circuit a digital voltmeter dvm.