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.
Rf field strength meter circuit diagram.
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.
Start your measurements by using low transmitter power and a near minimum sensitivity on the field strength meter.
Utilize a germanium locator diode like 1n34 yet aa119 is substantially more normal in europe a silicon one won t do.
The signal strength meter display uses analog meter 1 ma full scale.
You re measuring field strength from a transmitting vhf antenna use a vhf an tenna on the field strength meter.
Adjust c1 for peak reading.
This is an exceptionally simple rf field strength meter circuit.
The variable resistor on the field strength meter figure 3 the case circuit board and antennas for the field.
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.
The circuit shown here can be used as a wide band field strength meter and can.
The frequency is controlled by l and c.
Here is the schematic diagram of this rf meter circuit.
The amplification can be adjusted by p1 and with s1 switch we can select three frequency ranges.
Considering these factors a dual mosfet is used as an rf amplifier in this circuit.
To use turn on transmitter and meter.
The main stage acts as a crystal recipient.
A field strength meter fsm is a very useful circuit to detect and measure the rf signals and their strength.
How the circuit works.
The rf field strength meter circuit schematic.