These are all DX questions : 1) Is a reduction or increase in power directly applicable to the inverse square power law? For example, if a contact is made with 5 S units at the receive side and the person transmitting increases power from say 100W to 1000W, would the receiver see an increase of 10dB from 5 S units to almost 7 S units assuming there is no significant fading during the power change? 2) For someone like me that is currently only doing Rx "work" (more like fun to me), can I assume if I hear someone using any antenna (beam on 100 ft tower pointed at me, mobile, attic dipole...) that they would hear me back assuming they are close to my 100W limit? For example, if I am hearing someone well and they claim they are using 100 watts, if I were to Tx back to them with 100 watts, would it be safe to assume they could hear me about as well? If not, why not? Also note here I am saying any antenna insinuating that doesn't matter since I already hear them. That is, I am asserting this reciprocity property works for any type of antennas used. More simply stated, if an antenna tweak is performed on only 1 side of the link, both sides will benefit equally well for that particular link between them. 3) Is it possible that the DX paths between points are different depending on who is transmitting and who is receiving such that one person has an advantage over another? Specifically, are there certain DX phenomena that are biased more towards one direction than another at certain times during the day making assumption # 2 above false? I know we can't much control the Ionosphere but it is interesting to analyze it's properties by making observations and asking questions.