audioguru2
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low distortion, low noise, wide bandwidth.MNA said:
Yes. Use an FM transmitter and an FM receiver. The receiver can simply detect any modulation or can detect a certain tone frequency that has modulated the FM carrier frequency.
audioguru2
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A video transmitter block diagram is shown in Google, in Howstuffworks and in many other websites.
For TV, a video transmitter is an AM transmitter with a mixer to mix the sync pulses with the wideband analog video. Colour TV is a little more complicated since there are a few completely different ways that are used around the world.
For TV, a video transmitter is an AM transmitter with a mixer to mix the sync pulses with the wideband analog video. Colour TV is a little more complicated since there are a few completely different ways that are used around the world.
Receiver?? how?? how can i use it to operate as a switch(for eg. to switch on a transmitter(video tx for suppose) placed somewhere at a distance where my transmitting pulses(for switching purpose) can reach that can switch the second transmitter(video tx or ....) )
audioguru2
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Maybe you are not allowed to transmit RF without a permit in your country.
Maybe you are allowed to use a 433MHz certified transmitter module that has a short range and can be used by anybody who could also accidently activate your receiver unless you use a secure code.
Maybe you are allowed to use a 433MHz certified transmitter module that has a short range and can be used by anybody who could also accidently activate your receiver unless you use a secure code.
Range is not a big issue....it can be small to remain in the limits...... but what i want is to operate my tx (for suppose if I make a video tx..and it is put somewhere not far from my house or can be in my house...if range is realy serious!! I will want to switch on that tx by sitting in front of my tv....just what I am trying to do is to combine a remote switch and a video or audio tx......Can u guide me on this....
audioguru2
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The transmitter FM modulates a silent carrier since without the carrier there is a lot of noise and when receiving the unmodulated carrier there is silence.
The audio circuit works and activates the beeper when there is or is not any noise. The radio receiver circuit isn't shown so we don't know all the details.
The audio circuit works and activates the beeper when there is or is not any noise. The radio receiver circuit isn't shown so we don't know all the details.
Audioguru what do you think?
As I see it the transmitter has several faults, Q1 wrong way should work as a switch and key the transmitter, Q2 should be a NPN and for the final amplifier why it shouldn't work in class C :
As I see it the transmitter has several faults, Q1 wrong way should work as a switch and key the transmitter, Q2 should be a NPN and for the final amplifier why it shouldn't work in class C :
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audioguru2
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I searched for video tx and found many.... But I'm unable to decide which one is better and why.... I've attached one of them....... I really don't know how to judge... Perhaps, you can help me.... Please give me some tips .......
How can I combine my audio and video outputs from VCR to connect to this crkt(my guess ...from poptronix???)
Is this crkt not better than poptronix?.....this crkt uses crystal accuracy ...Isn't it?
View attachment 39010
How can I combine my audio and video outputs from VCR to connect to this crkt(my guess ...from poptronix???)
Is this crkt not better than poptronix?.....this crkt uses crystal accuracy ...Isn't it?
View attachment 39010
audioguru2
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This circuit can't be received by a normal TV. It is for the amateur radio microwave band.
It dosn't have an input for sound.
Its video seems to be FM modulated instead of AM modulated like broadcast TV.
Good luck trying to find its weird ICs.
It dosn't have an input for sound.
Its video seems to be FM modulated instead of AM modulated like broadcast TV.
Good luck trying to find its weird ICs.
audioguru2
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I don't know which TV system that transmitter works with.
Hi MNA!
These schematics you uploaded are not the easiest to build I would say, to build them you need some "extra" skills in RF technique.
Since the range is not an big issue why not use a RF-modulator from a scrap video then you have both audio and video transmitter or build your own:
http://www.web-ee.com/Schematics/RF_Modulator/rf_modulator.htm
These schematics you uploaded are not the easiest to build I would say, to build them you need some "extra" skills in RF technique.
Since the range is not an big issue why not use a RF-modulator from a scrap video then you have both audio and video transmitter or build your own:
http://www.web-ee.com/Schematics/RF_Modulator/rf_modulator.htm
Well. the poptronix circuit... just forget it.
You can find an RF-modulator in almost every video player, it's a small box with 4-6 pins, there is inputs for both composite video and audio and a pin for supply voltage.
If you look at the rear of a video you'll see it, it's where the antenna connector is.
You can find an RF-modulator in almost every video player, it's a small box with 4-6 pins, there is inputs for both composite video and audio and a pin for supply voltage.
If you look at the rear of a video you'll see it, it's where the antenna connector is.