Hi Mike
This has turned into a very long thread and you may not have read some of the early entries. I too balked at the term "senstitivy" as there is no defined spec for sensitivity. For the rest of the thread, in an attempt to match up with the question, I defined sensitivity to be "equal output for a given input" and so, in this discussion the intent was to equate sensitivity with gain, with a clear understanding that this does not define the weak signal performance without accounting for internal and external noise.
All of my numbers and suggestions are based on the receiver system showing a noise rise when the antenna is connected. Only Alan has brought into the conversation the case where internal noise exceeds the antenna noise and my response there is "get a better antenna".
I completely agree, if internal noise it higher than external noise then gain is not the answer. That was not the case in Roger's problem so far.
Warren Allgyer
9V1TD
Warren Allgyer