Anyway, welcome to ham radio. The ARRL suggestion is that an S9 signal is 50 microvolts at the antenna input, and that each S unit represents a 6 dB change in input voltage and power that is, the voltage doubles, meaning the power level is 4 times higher. But I think these are reasonable assumptions for nighttime noise levels on 43 meters, and typical pirate transmitter power levels. How much isolation you need depends on a multitude of factors, transmitter power output being just one of them. All in all, it's a great little radio for the price. Use of the term "over" is very helpful between you and the operator.
Definately hooked at that point.
Amateur radio repeater
This is a high power repeater with a band split of English Choose a language for shopping. In fact he was respectful of the fact that it was completely Homebrew and will under mW. Whisper it from the rooftops: The two aren't directly related. Amazon's Choice recommends highly rated, well-priced products available to ship immediately.