Hello ;

I got a circuit design which is already done someone else however in that circuit the rf transmitter is not good enough for the application and i have to replace that another RF transmitter.

The problem is that i have no idea how do that replacement for now because i did not this circuit before and i can not match the desing on board and the paper..

Could you help me how can handle that problem and give me some advices?

Thanks a lot have a nice day

 

You have not given us enough information for us to be able to help you.
What are you trying to do?
Show us some photos and schematics.
Provide specifications.

 

these are the circuits i need the change the rf components

 

Now we're getting somewhere.
The existing Tx is not good enough, right? Why?
Do you need to increase the transmitting range?
How much power is the exisiting Tx? What is the range?
What range do you need?
What is your Tx frequency and power?
What is your baud?
What are you transmitting?

We can't read your mind over the internet, at least not yet!

 

all the things ok except the comminication distance and i choose a suitable rf component for that comminication.
the problem i have already a circuit which is done before but i can not understand the design what i mean that when i look the picture that i send you before it is ok clear after that when i look the circuit design which is done before by someone it looks like too complicated

 

In short i decide the transmitter and receiver the problem how can replaced them on the circuit which is done before

 

I give up. I don't know. Not enough info. Someone else can have a go.

 

thanks anyway what do u need i try to explain more but my question is simple i have to change a component but i can not understand the design before can u give me some advice to understand that design. i dont have any problem about choosing any component i guess u understand something like that

 

Both the Transmitter & Receiver are modular units,& if the Transmitter antenna is a 1/4 wavelength type,I calculate that they both operate at around 440MHz.

The Transmitter is probably what is called a Low Interference Potential Device (LIPID) in my country.

If your regulations are similar to ours it will be restricted in radiated power,so increasing the Transmitter power output,or fitting a high gain antenna to it, may not be available options.

Two options which are probably available,are fitting a high gain antenna to the Receiver,or building a RF preamplifier for it.

If you find the existing circuit complicated,I would not advise you try the preamplifier,but you may be able to buy a suitable high gain antenna & connect it to the Receiver.

 

ok i see that is a good info 4 me thanks a lot. could u give me some advice how can i understand the paths because the person who designed before the circuit made the design a little bit complicated