Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: CrashOverron on November 16, 2008, 04:25:20 PM
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this doesnt actually have to do with robotics but i want to make an AM transmitter and receiver and i found these schematics transmitter (http://www.electronics-lab.com/projects/rf/011/index.html) and receiver (http://www.electronics-lab.com/projects/rf/006/index.html) but i was wondering if i had to use the variable capacitors or if i could use a regular capacitor and if so what would be a good value to use?
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Yes, you can use fixed value capacitor, but your receiver/transmitter will work on a fixed frequency. You will have to take some trial and error to get it to work (most of cheap capacitors could have capacitance differ up to 50% with the same nominal value, pretty much same for inductors).
Actual value of capacitor and inductance define your frequency. For LC circuit resonant frequency is defined as
w = 1/sqrt(L*C)
So, take frequency you want and calculate the value of capacitor for it.
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very much appreciated =]] thank you very much