TV audio video transmitter Schematic Diagram

<div dir="ltr" style="text-align: left;" trbidi="on"><div style="text-align: justify;">This is a simple TV <strong>audio video transmitter</strong> <b>circuit </b>can be constructed using this schematic diagram . This TV audio video transmitter circuit can be used to transmit video signals from VCR ( or some other device ) to a TV without using any cable .</div><div style="text-align: justify;"><br />Video signals input at jack J1 are first terminated by resistor R6 and coupled through capacitor C1 to clamping-diode D1. Potentiometer R3 is used to set the gain of the video signal; its effect is similar to that of the contrast control on a TV set.</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b>TV audio video transmitter Schematic Diagram</b></div><div style="text-align: justify;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN6nSLalPkVF7cNsD2IYgx0pWpLQr68xCIU7FixkYKMs3FxLKG9d9LFctXaEaQADgaSbcMJmvpCeYBaqCY-8tuWcDIdmOWVnVVQWWZsQBCcUOJlOvJLiwnYXph59quriy8aopjhYwZ8Ywj/s1600/TV+audio+video+transmitter+Schematic+Diagram.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="TV audio video transmitter Schematic Diagram" border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN6nSLalPkVF7cNsD2IYgx0pWpLQr68xCIU7FixkYKMs3FxLKG9d9LFctXaEaQADgaSbcMJmvpCeYBaqCY-8tuWcDIdmOWVnVVQWWZsQBCcUOJlOvJLiwnYXph59quriy8aopjhYwZ8Ywj/s400/TV+audio+video+transmitter+Schematic+Diagram.jpg" title="TV audio video transmitter Schematic Diagram" width="372" /></a></div><div style="text-align: justify;"> </div><div style="text-align: justify;"><br />Bias-control R7 can be used to adjust the black level of the picture so that some level of signal is transmitted, even for a totally dark picture.</div><div style="text-align: justify;"><br />RF-transformer T1 and its internal capacitor form the tank circuit of a Hartley oscillator that's tuned to 4.5 megahertz. Audio signals input at J2 are coupled to the base of Q3 via C2 and R4: the audio signal modulates the base signal of Q3 to form an audio subcarrier that‚s 4.5-megahertz higher than the video-carrier frequency.</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">The FM modulated subcarrier is applied to the modulator section through C5 and R9.<br />Resistor R9 adjusts the level of the subcarrier with respect to the video signal.</div><div style="text-align: justify;"><br />Transistors Q1 and Q2 amplitude modulate the video and audio signals onto an RF-carrier signal. The operating frequency is set by coil L4, which is 3.5 turns of 24- gauge enameled wire on a form containing a standard ferrite slug.</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">The RF output from the oscillator (L4, C7 and C9 ) section is amplified by Q5 and Q6, whose supply voltage comes from the modulator . Antenna matching and low-pass filtering is performed by C12, C13, and L1.</div><div style="text-align: justify;"><br />Resistor R12 is optional; it is added to help match the output signal to any kind of antenna.<br />To align this audio video transmitter you need to tune a TV receiver to an unused channel between 2 and 6. The TV must have an indoor antenna connected directly to it; an outdoor antenna or cable won't work. Make sure both potentiometers (R3, R7) are in middle position and apply power to the transmitter. Adjust L4 with a nonmetallic tool until the TV screen goes blank ,then fine-adjust L4 for the "most-blank" picture.<br />Connect the video and audio outputs from a VCR(AV source) to jacks J1 and J2 (respectively) of the transmitter .</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">After that you should see a picture on the TV screen: if you do, readjust L4 for the best picture; if you don't, check the board for any bad connections. Next, adjust R3 for the best picture brightness and R7 for the best overall picture.</div><div style="text-align: justify;"><br />Finally, adjust T1 with a nonmetallic tool for the best sound .<br />The TV transmitter combines line level audio and video signals, and transmits the resulting signal up to 300 feet. The circuit can be powered from a 9-12V power supply circuit .</div><div style="text-align: justify;"><br /></div></div>

TV audio video transmitter Schematic Diagram

This is a simple TV audio video transmitter circuit can be constructed using this schematic diagram . This TV audio video transmitter ci...

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