kodiak
Newbie level 4
Hello. I'm very inexperient with eletronics, but as a class project I've been working on a low power and low range AM transmitter. Unfortunately, I could not finish this project because I could not find the necessary material in the country I live (even in the internet). I could basically modulate an audio signal using a signal gerator as a carrier, but, my oscilator module can't achieve more than 400kHz. I've already tried to use a Wien's Bridge, and other Opamp based circuits, but they all have similar limits. I'm using a TL072CP, and I see that people can achieve the desired results using an TL072BC, but the second one is not sold here. I've discussed this with my professor, and he told me to do a Morse transmitter and receiver in the frequency I can achieve. But I'm afraid there won't be enough time to do it from the begining (I can't make the transmitter by my own, i would not be able to finish both of them in one week). So I'm in a position in which I really need your help.
I can still make a normal AM radio frequencies, but I wont be able to amplify nothing but the Audio signal with my opamps. What would you suggest me to use as a guaranteed functional oscilator? (I couldn't find 1MHz crystal oscilators here). I'm a little bit afraid of working with indutors (because of the need of coiling the wires and it's lack of precision), and that's why I was searching for opamp based oscilatiors.
Or do you think I should make the morse transmitter and receiver?
This were some of the circuits I've been testing:
(modulator)
(wien's bridge)
And this was my most recent hope (the oscilator I saw in an internet video)
The project is not meant to be an comercially acceptable transmitter (or/and receiver), it just have to transmit anything that can be understood as a signal transmitted in very short ranges (some centimeters are enough).
So thank you guys, you have no idea how worried I am because of this project, I really need your opinion and suggestions.
I can still make a normal AM radio frequencies, but I wont be able to amplify nothing but the Audio signal with my opamps. What would you suggest me to use as a guaranteed functional oscilator? (I couldn't find 1MHz crystal oscilators here). I'm a little bit afraid of working with indutors (because of the need of coiling the wires and it's lack of precision), and that's why I was searching for opamp based oscilatiors.
Or do you think I should make the morse transmitter and receiver?
This were some of the circuits I've been testing:
(modulator)
(wien's bridge)
And this was my most recent hope (the oscilator I saw in an internet video)
The project is not meant to be an comercially acceptable transmitter (or/and receiver), it just have to transmit anything that can be understood as a signal transmitted in very short ranges (some centimeters are enough).
So thank you guys, you have no idea how worried I am because of this project, I really need your opinion and suggestions.