CB transmitter

quantum1

Jun 24, 2004
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Jun 24, 2004
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This project here, I have multiple questions.
http://www.electronics-lab.com/projects/rf/018/index.html
First off, the microphone on the left of the schematic. The V+ I'm assuming, is where the positive terminal of the battery is to be connected indirectly. The ground smbol is for the negative terminal of the battery to connect to the mic. also. My question for you is what are you suppose to do with the input lead of the microphone. Is it just me, or are there some microphones with three leads coming out of them? I am pretty there are not ones like that, of course. I've seen that the input is just the V+. Is that true, or is that pish posh?
Another question, what does CB in CB transmitter represents.

 
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AVRFreakMan1

Aug 1, 2003
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Aug 1, 2003
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This circuit is a CB transmitter, not "reciever"(the correct spelling is "receiver").

CB means Citizen's Band.

There are microphones that need a small supply voltage(and limited current which is done by the help of the resistor R5) to be able to work(because they have embedded preamplifier). This is why the circuit has this option.
For microphones that do not need this, you can just leave it unconnected.

Kyriakos

 

quantum1

Jun 24, 2004
153
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153
AVRFreakMan, I modifyed it to the correct spelling. Thank you for your knowledge on a limited supply of curent for the mic., thus to put a resistor in series. However, you didn't answer my question on why there is a input lead.

 
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AVRFreakMan1

Aug 1, 2003
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Some microphones have three leads, othes have two leads.
One of those leads is surely the ground(or -V or 0V or GND or Common).
Both of these two categories might need supply that take from the third lead, if they have three, or from the second(which additionally serves as MIC_OUT), if they have only two.
For those with 3 leads, the one that is not the VCC nor the GND, it is the MIC_OUT.

 
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