The circuit diagram of the decibel meter in figure 1 stands out by its simplicity which is due to the type ad8307 monolithic demodulating logarithmic amplifier ic1 from analog devices.
Rf power meter schematic.
The circuit uses a dual op amp as a simple peak detector with the capacitor c1 holding the peak voltage between pulses.
Rf power meter components forward reflected sensor meter rf in rf out x x directional coupler.
Pictures of a homebrew 2 4 ghz rf power meter swr meter.
50 mhz frequency counter voltage meter swr pwr indicator circuit schematic schema wiring diagram diy project schaltbild shema.
Swr bridge covering hf to vhf circuit schematic schema wiring diagram diy project schaltbild shema.
A tap circuit supplements the power meter extending the upper limit by 40 db allowing measurement of up to 100 w 50 dbm.
Adjust c1 for peak reading.
The rf power in dbm can be read directly with a multimeter and i ve found it particularly useful for measuring rf filter response when combined with a sweep generator and an oscilloscope.
To use turn on transmitter and meter.
Qrp circuits for measuring rf voltage rf current rf power swr circuit schematic schema wiring diagram diy project schaltbild shema.
The power meter the cornerstone of the power meter circuit shown in figure 1 is an analog devices ad8307an logarithmic amplifier ic u1.
These take a small amount of power which is rectified and passed to a meter to provide a reading.
The measurand quantity to be measured is applied to pin 8 inp of ic1 via input socket k1 and capacitor c1.
It is possible to make high frequency rf power swr standing wave ratio meters using homebrew directional couplers and other easily available parts.
It has two directional coupler lines running parallel to the main through rf power line.
Here is yet another ad8307 based rf power meter which adds an opamp to produce a dc output voltage of 1mv dbm e g 0mv 0dbm 10mv 10dbm etc.
The schematic diagram of the peak detector circuit connected between the rf power detector board and the display board is shown below.
Here is the schematic diagram of this rf strength meter circuit.
Rf decibel power meter description.
Turd rf wattmeter schematic.
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.
Rf programmable attenuators digital step attenuators from mini circuits provide precise level control from 0 to 120 db for applications up to 40 ghz with easy connection via usb ethernet rs232 and spi interfaces.
The diagram shows a simple swr bridge or swr reflectometer circuit.
Mini circuits is a global leader in the design and manufacturing of rf if and microwave components from dc to 86ghz.
Swr protection circuit 1 3 2 1 11 4 2 reflected reflected power 5 6 7 4 1k 12 13 14 1 1k 13 5 vdc 8 vdc 1 uf to 4 vdc foldback treshold 7808 390 w swr led radio shack 276 0017 100k forward 100k 10k 3 1 21m 10 9 8.
