VHF-Tr-100-150MHz-100m

Hi dear members.
Is it possible access to a good simple VHF transmitter schematic without any error?
I really need one with 100-150 MHz band and at least 100 meters distance spreading.
Your help will really be appreciated.

Hi again.
It seems that nobody wants to help me or can't help for this.
One another thing;
Is here any knowledgeable or resourceful man in electronics who can help find errors in one VHF circuit which doesn't give any output wave? If yes, let me know, so put the schematic here.

Post the schematic and we'll take a look. As for your first post, it begs for questions more than answers. What's the modulation type and channel bandwidth for the transmitter. CW, SSB, FM (and deviation amount), AM, Spread Spectrum? How are the channels selected; analog continuous, digitally? Much better to post a schematic for review than to ask broad open ended question. Distance is more a matter of output power stage and antenna. It's the modulation type and the channel bandwidth and selection method that drive the design.

ccurtis said:

Post the schematic and we'll take a look. As for your first post, it begs for questions more than answers. What's the modulation type and channel bandwidth for the transmitter. CW, SSB, FM (and deviation amount), AM, Spread Spectrum? How are the channels selected; analog continuous, digitally? Much better to post a schematic for review than to ask broad open ended question. Distance is more a matter of output power stage and antenna. It's the modulation type and the channel bandwidth and selection method that drive the design.

Click to expand...

Hi, thank you for your regard.
What I want is an Analogue TV transmitters.
First of all; I should make a correction: I need one Analogue TV transmitters with 170 – 210 MHz.
The man who’s given this Schematic claimed it can give 150 – 300 MHz, but after making, it gives no output wave. There should be an error in schematic. Any help to fix it will be really appreciated.
Thanks in advance.
View attachment 65520

a couple of things i see wrong with that schematic. first of all there's no sideband suppression. second, both the AM and FM modulation for the video (AM) and audio (FM) are being applied to the transistor that is also the oscillator that generates the carrier. you will end up with sync and video noise in the audio, and the audio will bleed over into the picture. there should be a frequency modulated oscillator for the audio, separated by a few Mhz (4.5Mhz in the US) from the video carrier which is amplitude modulated and then most of the lower sideband filtered out as is shown here: http://ntsc-tv.com/ntsc-index-09.htm

Simple circuit designs such as that are too finicky in the adjustment and not stable enough even if there are no errors in them. In addition, such as the quirks that unclejed pointed out, there are too many compromises made for the sake of simplicity to arrive at a decent outcome. I don't have a schematic for you, but you might be interested in an assembled product such as this:

https://www.electro-tech-online.com/custompdfs/2012/07/41164.pdf

I can't vouch for the quality of that device either, but trying to help here. Maybe good, maybe not. To get the range you want, you may need to add a low power, linear RF amplifier to boost the output if a high gain external antenna doesn't do it. Not that I am advocating that idea, mind you. The FCC doesn't take too kindly to such things, not to mention the neighbors.