Talk Over circuit schematic
A very usefull talk over circuit which you can use in your radio stations, club or anywhere you want to speak over music without any movement of potentiometers. Just talk in your microphone and the music level will drop accordingly to your voice.
Talk-over circuit schematic:
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UUS 65 - 73 MHz fm transmitter
A basic UUS 65 73 MHz fm transmitter circuit schematic which can be used as uus oscillator with no explanation …
65 - 73 MHz transmitter ( oscillator ) circuit components:
L1 = 8 t / 0.3mm / 6mm
L2 = 8-12 t / 1mm / 15mm / 1mm gap
SRF = 60t / 0.2mm / 3mm / ferrite
FM Power Amplifier BLY87A, BLY89A, KT920A, KT925B
A very simple fm power amplifier which can deliver 4W rf power with 12V power supply and BLY87A or KT920A and 20W with BLY89A or KT925B.
If you use BLY87A or KT920A the input power must be 0.5W and 4W if you use BLY89A or KT925B. This fm power amplifier is designed to work on 50 Ω antennas and a maximum power supply of 14V and in 88 108 MHz band.
Use only metallic trimmers, a good heatsink for the transistor and ceramic capacitors and keep the pins very short.
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