Measurement
Radio field signal strength indicator
A radio field signal strength indicator is very usefull for determine radiation patterns of transmitters antennas. An ancillary antenna must be put close to main transmitter antenna. The received signal is applied to L1,L2 and C2, this allows the field indicator circuit to adjust to the same frequecy as the transmitter. With the coils values [...]
UHF indicator - wavemeter
UHF indicator or wavemeter is some kind of device that measures frequencies and determines LC circuit frequecy resonance . This device does not need to radiate.
The oscillator is build with T1 and T2 (2 x BF494) and can be adjusted with C1 and Lx. The Lx coil is connected outsite of the metal box and [...]
Temperature measurement circuit schematic
The multimeter is a measurement device most used by engineers and we use it in this temperature measurement circuit schematic. The temperature sensor is LM335 wich has a linear characteristic of 10mV / K . In the production process this electronic device is calibrated so can provide 2.73V at 00C. LM336 is used as a [...]
