I tried that, it works well.
The bigger the loop the better up to a point.
I tried a number of setups with and without a preamp at the loop, various preamps and baluns with mixed results.
The thing with loop antenna's at my QTH is I really need a rotator, as they are directional, and I never bought one.
I also transmitted into a few preamps at the loop doing comparisons and switching back and forth between multi antenna's.
It just takes a second to forget which antenna you have selected....
In my case, I had most of the local noise come from one direction and could null that out very well, but you really need to be able to turn a loop as conditions change and for different bands.
The bigger loops worked better on the lower bands, I tried making a larger one out of copper tubing which worked well 80 meters and up but did not hold up as it was just an experiment.
I used quad shielded cable from CATV hookups and made balun's to test.
I think if you only had a vertical antenna, a loop would be a great RX antenna to kill the noise.