Actually, that's where I get this circuit diagram and the 1W Power Transmitter there comes with 2 variations just replacing the capacitor it will have 902MHz and 1300MHz, I'm confused if I will do the same to have the frequency to Channel 40 or I will modify the Inductor as well?The schematic of the transmitter that you posted is from the book in the link below:
Build Your Own Low-Power Transmitters: Projects for the Electronics Experimenter: Rudolf F. Graf, William Sheets: 9780750672443: Amazon.com: Books
Build Your Own Low-Power Transmitters: Projects for the Electronics Experimenter [Rudolf F. Graf, William Sheets] on Amazon.com. *FREE* shipping on qualifying offers. Build Your Own Low-Power Transmitters: Projects for the Electronics Experimenterwww.amazon.com
Try to get the book, because there is plenty of information how to build or to modify this transmitter.
Thank you, Sir! I'll re-read the book again and study it. Last question is this circuit can receive to digital TV?Both is possible. Presume you are aware of elementary LC circuit relations. 902 MHz caps need to be roughly doubled to arrive at 629 MHz resonance. The schematic seems to indicate capacitively loaded micro strip resonators in some places, resonance frequency is slightly different from lumped LC. I expect the book discusses the topic.
Can you guide me with that? Thank you in advance.This circuit is too complicated and it will create so much trouble for a newbie.
If I were you, I'd use a TV Modulator IC and then a Power Amplifier. But the target is to learn RF discrete circuits, OK, you can change the oscillator circuit and abandon the double and tripler stages.
For instance I'd use a single transistor Collpits ( Clapp too ) varicap driven oscillator with a simple PLL ( MC145151)
The rest of the circuit can be used some modifications.
What type of TV Baseband Signal do you intend ?? Analog or Digital ? You can use this IC to modulate the Analog Video Baseband Signal. It accomplishes all necessary functions for that purpose.Can you guide me with that? Thank you in advance.
Digital Signal, should I replace the IC with that one?What type of TV Baseband Signal do you intend ?? Analog or Digital ? You can use this IC to modulate the Analog Video Baseband Signal. It accomplishes all necessary functions for that purpose.
Thank you, Sir! Is it possible if I use digital to analog converter? Can't find a basic low power circuit for audio and video digital tv transmitter on google. Do you have suggestions or recommendations in the circuit?The IC is only suitable for analog TV. Digital TV is far more complicated, you have to generate baseband signals using mathematical functions and then mix them with a high frequency oscillator to shift them to your final frequency. It needs fast digital devices to generate the baseband and linear mixers and amplifiers to make the result usable.
Brian.
I think its ISDB-T standard here in the Philippines.Please review the comment about digital TV in post #6. Which digital TV source are you intending to transmit? You may want to google for Divital TV standards and QAM.
If it's so, forget about it. You can not make this system because it's too complex to build.I think its ISDB-T standard here in the Philippines.
If it's so, forget about it. You can not make this system because it's too complex to build.
Thank you, Sir. How 'bout this one? I found on google it says that it is a DTT TV Transmitter do you think its working and need a programming/code to make it functionable? And also, what is the equivalent or replacement for TR391AV can't find on google. Thanks.It is very similar to my own analog TV transmitter although mine works at 1.3GHz. For ANALOG television it is fine but it will not work for digital TV. Sending digital TV is far more complicated. It isn't as simple as making a digital signal then feeding it to an analog transmitter. The extra information in a digital transmission cannot be sent on a single carrier like analog uses, you need a complex mix of AM, FM and PM called QAM or an even more complex system called OFDM. These signals are produced by mathematical algorithms, then have error correction bits added to them and finally sent to quadrature modulators, it is completely different to the method used in the schematic you posted.
Brian.
I found it here Sir, this link.I'm not sure what that is except it has four AV input channels. It may be an SDI generator.
Where did you find the schematic? Even if it can produce a digital signal it would need up-mixing to final frequency.
Brian.
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