Sensitive RF Voltmeter Probe Circuit
This Circuit measures RF voltages beyond 200MHz and up to about 5V.
| PARTS LIST | |
| R1 | 4.7MΩ |
| R2 | 1MΩ |
| R3 | 1MΩ |
| R4 | 100kΩ |
| R5 | 330Ω |
| R6 | 10kΩ |
| R7 | 10kΩ |
| VR1 | 2kΩ |
| VR2 | 2kΩ |
| C1 | 0.001µF (Disc Ceramic) |
| C2 | 0.001µF(Disc Ceramic) |
| C3 | 0.01µF |
| D1 | 1N914 |
| Q1 | 2N3819, 2N5459, MPF102 |
| M1 | 100µA |
| S1 | Switch |
| BT1 | 9V Battery |
The Diode should be mounted in a remote probe, close to the probe tip. Sensitivity is excellent and voltage less than 1V peak can be easily measured. The unit can be calibrated by connecting the input to a known level of RF voltage, such as a calibrated signal generator, and setting the calibrate control.
VR1 =For Calibrate
VR2 = For Zero set
MPF102 N-Channel JFET VHF Amplifier Pin Configuration
Please send your ideas, which are very important for our success…
Leave a Reply