20Mhz ASK Receiver won't work without earthing

Discussion in 'Wireless & RF Design' started by Havoc, Feb 6, 2009.

  1. Havoc

    Thread Starter New Member

    Feb 6, 2009
    Hello folks,

    I am a long time reader but just a recent member on this forum. As the title suggests I have designed and built a 20Mhz ASK transmitter and Receiver. Whilst my transmitter works perfectly fine without earthing and transmits throughout my whole house, my receiver however only works that same distance if I have a proper earth connected to it's neutral (-) path.

    The moment I disconnect the earth from the neutral my receiving distance is reduced to about 5cm. At first I thought it was some kind of RFI or EMI that was picked up by my breadboard due to the large content of metal, but now that I have built a PCB and am still experiencing the same problem, I am kind of stuck.

    I was hoping that there could be someone here who has a little bit more experience wit RF transmitters/receivers and the effect of earthing.


    here is my receiver schematics.

    Last edited: Feb 6, 2009