Wireless am microphone


Posted on Nov 17, 2012

Transistor Ql and its associated components comprise a tuneable rf oscillator. The rf signal is fed to transistor Q2, the modulator. Operational amplifier ICl increases the audio signal and applies it through resistor R4 to the base of Q2. Tune an AM radio to an unused frequency between 800 to 1600 kHz. Tune Ll for a change in the audio level coming from the radio. Peak the output by adjusting L2


Wireless am microphone
Click here to download the full size of the above Circuit.

If Ll is disturbed, it may be necessary to readjust L2 for peak performance. Depending on the impedance of the microphone audio sensitivity can be increased by decreasing the value of RIO and vice versa.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Single Chip FM Transmitter
Schottky Field Strength Meter
Push-on-push-off electronic switch
Dual astable multivibrator
Light turning bike using IC LM3909
600 Watt Mosfet Power Amplifier with PCB Schematic Diagram
power supply Why is my simple boost converter giving me such a high peak output voltage
monitor splitter
Nostalgic Crystal Radios
A 30 Mtr Direct Conversion Receiver for QRSS
IF AGO network circuit diagram
DK-5A, DK-5AD AC power control circuit
A watchdog circuit diagram



Top