interference question

[mstechca]

Suppose I have an FM receiver running at 6V DC with the bandwidth of 200Khz. Lets say it is tuned at 100Mhz.

Also, assume I have an FM transmitter powered by 6V DC. The setting on the FM transmitter is at 200Mhz and the bandwidth is 200Khz as well.

Now if I combine both units together, I can avoid one power source and have both units share one power source. My point is that I want to see myself having a transceiver without it causing interference to itself.

Is there any side effects I should be aware of if I did this? and do I need to maybe double the voltage?

I don't want to use dual rails, and I don't want each part individually powered.

 

[TheOne]

Unless you want to talk and listen at the same time, the receiver can be off while you transmit and vice versa.

 

[stevez]

Two things to consider.

1. While the receiver has a limited bandwidth a strong enough signal that is out-of-band might still get thru. The characteristics of the receiver and the characteristics of the transmitter would have to be evaluated to know what will happen with any degree of certainty.

2. Kind of contained in #1 but worth mentioning - the output of the transmitter is likely to contain components at other frequencies - they may be way down in power but in close proximity the receiver might 'hear' them.

In some cases, when transmitters and receivers are co-located the reciever front ends are robust - and sometimes additional filters are added to reduce the impact of the out-of-band energy.

If you've addressed those issues and are only concerned about the common power supply you might consider significant RF filtering of the power supply leads as a way of containing the RF in the transmitter and keeping it out of the receiver.