Electronics > Beginners
How do i reduce the drivelevel of the crystal to 100 uW?
Scarlett133:
How do i reduce the drivelevel of the crystal to 100 uW? Possibly with an Resistor?
Circlotron:
Reduce the supply voltage probably. My guess is half supply voltage will reduce power output down to one quarter.
Scarlett133:
No i meant the crystal oscillator, it needs 100 uW typically to much and it will break, i would try to use some resistors but i dont know which yk
Marco:
There is no voltage amplification, the output power is set by the output voltage swing, the crystal power is also set by the output voltage swing (and crystal resistance at resonance). There is no knob to turn to lower voltage/power across the crystal without lowering the supply voltage.
If you want to use some tiny crystal with a lower voltage swing, but have the same output power to the antenna, you'll need a different circuit.
CaptDon:
First off, that is a horrible circuit, probably need an RF bypass capacitor on the key side of the RFC, second, it is a horrible circuit. Why reduce crystal drive to 100 microwatts and how do you know the crystal can't endure substantially more? 100 microwatts is .1 milliwatt. I don't know of any crystal that physically couldn't handle at least 1 milliwatt and 10 milliwatts being far more typical, a factor of 10X or 100X your spec. Is power conservation an issue here? Supposed to run on a AA cell for a year? B.T.W., F.C.C. part 95 regulations specify 100 milliwatts D.C. input power so if you are making a little unlicensed QRP transmitter you have lot's of room to increase the power. What is the goal of this project?
Navigation
[0] Message Index
[#] Next page
Go to full version