Here is the situation: have an inverted V for 80m and noise level is
S9.. Not good really....

Dunno...Sounds like it was working to me.

I did the next logical step and tryied magnetic loop for 80, reciving
only, indoors.

What are you trying to hear? Sounds kinda illogical to me, if
you are working NVIS... :/

What would you do in this situation? Loop, magnetic loop, dipole,
short
beverage perhaps???

I'd go back to what was working. The dipole. If the noise is from the
shack,
the use of baluns or chokes to decouple the feedline can be used.
But I think the noise you heard was the normal atmospheric noise you
would hear on 80m. I often get S 8-9 noise levels on 75 until winter
really kicks in. It's normal. Noise is normal. It's RF. I'd be more
worried
about *not* hearing any noise, than I would be hearing it.
Also, don't lay the antenna on the roof. The higher you can get away
from
it, the better. A loop will be no better than the dipole in general.
Both are about equally efficient if fed with coax. But the loop is
more wire, and more work..
On 75m NVIS, almost all signals will be over the noise, unless you
have a local T storm brewing...Noise is not an issue...Well, not to the

ones with decent antennas... To one using a full size dipole fed with
coax, even 100w is plenty to get over 95% of the noise you will run
into. An S 9 noise level is no big deal if the signals are 20-40 over
9.
And this is the norm.. Only the guys running funky gimmick antennas
will be hard to hear.. :/
There are some weird ideas around about noise... Almost as many
fairy tales as with grounds and shielded loops.. No joke.
Good antennas pick up noise. That is what they are designed to do.
After all, noise is just rf like any other signal. If the antenna is
"low"
noise, that usually means it's half crippled in some way, unless the
noise is ingress from the shack. :/ And thats from the lack of a balun,

choke, etc at the feedpoint. Easily cured. Just rolling a few turns of
coax into a choke can reduce much of it. But like I say, I think your
noise was normal band noise. Listen now, after the cold front blew
through the country. I bet it's a tad quieter on that dipole now.
MK