Field strength meter
A sensitive and reliable field strength meter is an invaluable instrument in amateur radio and in radio controlled model area. A field strength meter is used to align an antenna to get the best possible gain, to determine the transmitting range of radio controllers …
Designing the field strength meter to be sensitive it is a requirement because there must be as many wavelengths as possible between the meter and the transmitter, the measurement can be done without using a stronger carrier signal and most of the radio controllers are of low power type.
Considering these factors, a dual MOSFET is used as an RF amplifier in this circuit. The amplification can be adjusted by P1 and with S1 switch we can select three frequency ranges:
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.
The field strength meter circuit schematic
Active components: 3N140, 3SK35, 3SK37
Random schematics
If you enjoyed this post, please consider to leave a comment or subscribe to the feed and get future articles delivered to your feed reader.
Comments
No comments yet.
Leave a comment