rf tranmitter/receiver help

Discussion in 'General Electronics Chat' started by bob101, Feb 18, 2013.

  1. bob101

    Thread Starter New Member

    Feb 18, 2013

    just created a rf transmitter and receiver project using the circuit

    but i am not able to make it work here is the schematics that i have followed

    rf transmitter
    Code ( (Unknown Language)):
    1. http://www.botskool.com/images/elec/brfrc2.jpg
    rf receiver
    Code ( (Unknown Language)):
    1. http://www.botskool.com/images/elec/brfrc3_1.jpg
    i have used 850k resistor instead of 750k resistor for transmitter circuit and
    36k resistor for receiver circuit and also used 10nf capacitor ( .o1uf )
    with 9v battery supply each for transmitter and receiver. and assembled it in a bread board
    i am confused with antenna here (consider me a electronic newbie here )
    i just took an insulated copper wire and coiled it and removed the insulation of one end and inserted into breadboard attached at the end of copper wire since the copper wire was thick and it was not going inside the bread board . please help me here . do i need to remove the isulation of the copper wire completely in order for it to work . how many winding should i make and what length of the copper wire should i use . i only need a 10 ft to 20 ft transmission

  2. Meixner


    Sep 26, 2011
    You should use the proper value resistors because they set the data rate.
    The antenna wire can have insulation on it, 8 to 10 inches should be good.
  3. bob101

    Thread Starter New Member

    Feb 18, 2013
    this is the assembly that i have done in the bread board i have used 850k resistor instead of 750k and 36k instead of 33k resistor instead of .01mf i have used 10nf which is the equivalent of .01mf . Please compare it with schematic and correct me if some thing went wrong . i have added the picture of copper coil also pleas say if it is correct



  4. bob101

    Thread Starter New Member

    Feb 18, 2013
    any please
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    Can you post your images as attachments? The thumbnails aren't loading a large image for me.

    Where did you purchase the Tx/Rx Modules from, do they have a support forum or a FAQ page that addresses their use? If so, post a link.

    With the little info known, I can't really give you much advice other than the fact that solderless breadboards aren't much good for carrying signals > 2Mhz or so for any distance at all, the inductance of the tracks may be de-tuning your antenna, and it may need to be compressed or stretched to compensate.

    What test equipment do you have? What speed is the data being transferred at between module and IC?

    You may have better luck wiring the antenna straight off the antenna pin on the module rather than routing it through the breadboard.

    What are you currently seeing in operation, and what is the expected operation?
  6. lath

    New Member

    Mar 16, 2013
    Bob101, I'm just curious if you got this to work. The images look like something I have tried twice over the last 5 years and never worked. LOL...I'm thinking about trying this RF path again so I was going through posts for ideas.