Range Issue of RF 315Mhz Receiver and transmitter using PIC18F4520 microcontroller!

[SAM_101]

Hey Everyone!
I just used an RF transmitter and Receiver of 315Mhz to send and receive data through PIC18 Controller! The language I used to program it was mikroC.
First, I used a monopole straight antenna with it and used the transmitter to send data to receiver! The transmission and reception was working for quite a good range. Next, I thought of attaching both the receiver and transmitter to my two microcontroller modules. I mean each microcontroller module had both receiver and transmitter attached to it.
I did this so that when my Master(Transmitter) would transmit some data, then my Slave(receiver) could acknowledge him back too that the data had been received successfully. After I programmed it that way it was still working fine. The problem came when I tested it's range which had reduced considerably. The range went to almost more than half as it was when I was using just a single transmitter and receiver.
My question is does anyone know what might be the problem as to why my range of data communication has reduced so much? And can anyone please also do give me some tips as to how can I resolve this issue?
I have attached a picture of transmitter and receiver I am using! I would be very thankful If I could get some pointers on how to solve this issue!

 

[davenn]

its most likely that the transmitters are desensing the receiver beside them
this would easily reduce the range

how to overcome ... best way would be to use the 315MHz in one direction and 433MHz modules for signals back in the other direction
The 100 or so MHz should provide enough separation of TX and RX freq's to avoid receiver desensing

Dave

 

[SAM_101]

You mean I should use a 315Mhz transmitter and with it a 433 Mhz receiver on one module?
and the same configuration on my other module too?