An outside loop works very well for nulling the noise and still
allowing you to hear the weak stations.
In most if not all of the ARRL Antenna Books, there is a chapter on
a 160 meter receiving loop, you can just scale this back for 80m.
I dont have the book here now, I think the lenght was something like
25' or so for 160m.
It is made out of a 75 ohm piece of coax that goes around once,
connected to a air variable cap. The braid of the coax is cut at a
certain point in the loop.
Its not that big at all even on 160m and can be put up on a pole and
turned by hand or even by a small TV type rotor.
On 160m with terrible local power line noise I was able to hear many
stations including DX stations on the loop that I could never hear on
my Inverted L transmitting antenna on 160m.

73s
Craig N0BSA