Hi all!

I want to design a schematic for an AM transceiver, starting from the transmitter...I am keeping in mind that the transmitter consists of 5 parts (correct me if I'm wrong!):

1) Mic/Line Input (should I include a mic-preamplifier?)
2) Oscillator (what kind should I use for this application?)
3) Mixer (can anyone advise me on something more specific?)
4) RF amplifier
5) Antenna

How would I go about starting the design process? How should I pick the circuits that are good for this application? Is there any help you could give me on this, any good resources to read?

Thanks for taking the time!

 

1) You have several options, an op-amp is probably best.

2) LC oscillator is the simplist but if you want more accuracy then go for PLL and a crystal oscillator.

3) Can be incorperated into the oscillator.

4) This will need to be a linear amplifier so don't expect it to be very efficient. Another more efficient option is to build a class C amplifier and modulate the switched mode power supply (which is powering it) with the audio.

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.

 

Of course the very small signal from a microphone needs a preamp.
A transmitter has a modulator, not a mixer.

__________________
Uncle $crooge

 

Since you are talking about a tranceiver, you should add an IF amplifier, a modulator, and TR switching just to name some more blocks.

__________________
The great thing about electronics is unlimited ways to do the job. The only limit is one\'s imagination. I generally think my way is best.
Show me a different way. I have an open mind.

 

The receiver has not been mentioned.
It might be a crystal 'radio", a super-regen, a tuned RF or a super-heterodyne.

__________________
Uncle $crooge

 

hey, I would like to ask a question: what's the difference between a single and a double balanced mixer?

excuse me for my ignorance :S

 

also, i found these designs on the net:

http://www.radio-electronics.com/inf...nced_mixer.php

will that do the job??

 

Amateur radio publications, 1960s vintage, might be a good place to look as AM was still quite popular.

__________________
stevez