TV tx

[SM2GXN]

As I told you if range is not an big issue  ;D
Just connect a short piece of wire to the center pin of the output connector of the RF-modulator and a short piece of wire into the antenna connector of the Tv-set, if the distance between your tv and video player isn't to far you will se the video sent by the video player on the tv screen. You'll have to put your tv on same channel as the RF-Modulator otherwise you wont see anything.
Forgot to mention, the two wires act as antennas.

 

[MNA]

Of course Sir, I said in my previous posts that range is not a big issue..... But I said that  for remote switch (i.e. for switching ON or OFF my tv tx through a remote or u can say some another tx........That was only a design idea .....I'm not an expert.... )..... TV tx should have a good range but I'm ineterested in better quality than range....but range will be a bonus....
The simplicity of RF Modulator gives me an idea that it's range will be very short....I don't know how much....
The web-ee modulator contains only 1 input for video..... ?

 

[gogo2520]

Hello MNA
        take a look at this  http://home.att.net/~wzmicro/avsender.htm
  I think this what your trying to do
                                    have fun
                                      gogo

 

[SM2GXN]

You are right MNA that circuit is only for video.
The link gogo2520 posted show how a RF-Modulator is built, as you see there is input for video and audio.
To boost the signal from a RF-Modulator which is usually in the range 60-80dBmV a antenna preamplifier can be used or build an small RF-amplifier that cover a bandwidth of at least 8 Mhz for the UHF channel in use, it has to be broadbanded.
The quality you get is same as you get from your video, when it comes to remote do you mean those units you can buy that both transmit video/audio and let you switch channel on another tv-set?

 

[MNA]

Thanx Gogo,SM2GXN.
Remote,,,, just to switch on or off my tv tx placed somewhere at a distance......
Well,I think it is better for me to concentrate on the tv tx than remote b/c without tv tx  what's the purpose of remote  ;D ;D  .....
You said,"Well. the poptronix circuit... just forget it."
ok I will forget it but only one last question about that.....ISn't the poptronix crkt and this avsender posted by Gogo doing the same thing ? .......why r u sayng me to forget it? ..... Is there anything wrong in the circuit ? .... I became curious with yr advice of forgetting it......
Thanx.

View attachment 39015

 

[SM2GXN]

Hi MNA!

No there is nothing wrong with poptronix wireless link my friend  it's just that it is very high frequency 1250Mhz, firstly there is no PCB (printed circuit board) layout which is very critical at high frequencies, it's a matter of less than mm accuracy, well maybe not that much in this circuit but some RF experience is needed, for the 2nd you have to make an antenna which is not that hard but if you want to go by the book it is.
For the third you have to make a receiver for 24cm/1250Mhz and either down convert to the UHF band or demodulate the signal in order to get your audio and video out.
That's why I say forget it  ;D
Hope this satisfy your curiosity MNA

 

[SM2GXN]

Forgot to comment on gogo2520 circuit the av-sender has much lower frequency about 1/5 which makes things a "little" easier, you can ofcourse build that one if you like but the easiest way is to use a RF-Modulator.

 

[MNA]

Thanx SM2GXN,
As u know I'm new to electronics,I want to study about these transmitters..... so, if you could suggest me any article or book available online,then it will be of great help to me......
May be in the resources section.......but I'm using dialup and unable to download those books due to connection problems now-a-days.....If anyone can filter those books list and specify me which one is the best for studying these transmitters,then I'll arrange from somewhere to get the book on cd.....I know your time is precious but it will be of great help to me.
Thanx.

 

[SM2GXN]

Hi MNA!

For couple of years ago I had dialup so I know what you are talking about
There is lots of good books and web pages about transmitters, to understand those books you will have to read some fundamental electronics, there is really no shortcut you have to struggle through all of it but please don't give up even though some pages in a book seem to be the most boring you have ever read 
I'll do my best to find something and hopefully there is other people on this forum that can contribute too.

 

[MNA]

Hi,
If there is no shortcut, I will go through anything which will lead me to understanding these......
My subject is electronics but I'm only a beginner and wants to go fast.....that's why I'm always try to understand everything...... I've joined this forum for the same reason and I hope u all will help me.....
Will be waiting for any replies for suggestion of articles or books....
Thanx.

 

[MNA]

Want to know about MC1374 IC.....saw a schematic based on it......

 

[audioguru2]

Want to know about MC1374 IC.....saw a schematic based on it......

Try searching on Google. This is on Google's 2nd link to an MC1374:
http://www.epanorama.net/counter.php?url=http://www.spelektroniikka.fi/kuvat/mc1374.pdf

 

[MNA]

Thanx Audio,I've seen that before posting ..... Actually,I wanted to know about the benefits and demerits of this IC.......Is it better than those crkts available on the net with discrete parts transistors........ As in my previous posts u said about one or two crkt that they can't be received by normal TV...... One thing more ,here tv system is PAL...... Also I'm not a very practical person,Is this ic commonly available?

 

[MNA]

I think the crkt I've is received by a normal TV..... Below I've attached it.....

av_modulator.pdf

 

[MNA]

:-[ :-[  Is it not for PAL(5.5 MHz) ?I forgot to check that before...

 

[audioguru2]

I have an MC1374 in a TV convergence generator that I made about 30 years ago.
Digikey is a huge electronics parts supplier and they don't list it, so it is probably not made anymore.
The circuit you attached is not designed for your TV system.