Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
North America uses 75us and Europe, Australia and Asia use 50us.
In my FM transmitter the 470 ohm emitter resistor for the preamp transistor is bypassed with 150nF for North America (470 x 150nF=) 70.5us. Pretty close to 75us.
The 470 ohm resistor is bypassed with 100nF for Australia and Asia (470 x 100nF=) 47us. Very close to 50us.
It is simply a first-order highpass filter.
The transistor will not work properly with its emitter resistor much too high at 10k ohms. It is almost cutoff.-Then...in normal situation, may i use 10k with 5nf to get exact 50uS pre-emphasis?
- But in your Mod 4, i think i can't use this 10k at emitter of pre amp becaues of biasing factor, can i?
The 100pF capacitor from base to emitter prevents the audio preamp transistor from amplifying the very strong radio signal which would cause it to have severe distortion.I think in your pre-emphasis, 100pf is also very important. Without this capacitor, the audio is not clear. What is this actually?