Guys, I got to doing some calculations and I realized that exceeding -15dBm on the receiver circuitry could be a lot easy than it seems to amateurs like me. So, I wanted to run this by some of you because I know that you guys have far more radio engineering knowledge than me.
So, lets take a situation for me. Lets say there is a 100-watt transmitter within proximity of me. And, I never thought much about it but obviously that could be a problem. When I use the link budget calculation I enter in 50dBm for the transmitter power, set zero for transmitter loses, set zero for receiver loses, set 5db for both TX and RX antennas. Then for the distance I have to put in about 3200 feet in order to only see a link budget of -15dBm. I know that is only for perfect world conditions and then its even more complicated in reality but I figure that should give me a fairly good idea. It is actually scary because I used to tinker with my B200 less than 500 feet from an antenna that was 50-foot up around 154mhz. Now, I am not sure what part of the RX chain is sensitive. It could be after filtering which means that -15dBm is only for a signal that gets through but I suppose also to be on the safe side I might need to consider anything. Anyway, it just took me by surprise when I realized how much and how easily I could exceed -15dBm. I know too it depends on time so that 1ns of -5dBm might not burn something up but you know in my case this 100-watt FM transmitter would transmit for a few seconds at a time. What are your thoughts, suggestions, or ideas?
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