RF 315Mhz Receiver and transmitter Issue using PIC18F4520 controller!!!

[SAM_101]

Hey Everyone!
I just used an RF transmitter and Receiver of 315Mhz to send and receive data through PIC18F4520 Controller!
First I used a quarter-wave monopole straight antenna with it and it was working fine! Then something went wrong! Now the receiver just receives data for once and then doesn't altogether!
Also, when it was working, it just worked in line of sight scenario!
Could some one help me with it please and also I would be very thankful if someone could explain to me the specs I require if I need to mount a helical antenna on it rather than a quarter-wave monopole one?
Or how can I increase it's distance of communication?

I have attached a picture of transmitter and receiver I am using! I would be very grateful If I could get some pointers on how to solve this issue!

 

[shahbaz.ele]

dear these modules work in short range because of RF power.
here is a transceiver module having range of 4Km.
DataBridge of starmann electric.

 

[SAM_101]

dear these modules work in short range because of RF power.
here is a transceiver module having range of 4Km.
DataBridge of starmann electric.

But the issue with me is that it isnt even working now when receiver and transmitter are close to each other!
Receiver receives a data only once and after that it doesnot receive even when i am constantly pressing the button to transmit from my receiver!
And also on the oscillator it shows that the receiver receives data from transmitter but it doesnt show anything on the LCD of my PIC18 Controller! Any suggestions?