Ken Bessler wrote:
Take 2 antennas on 6m - one is an inverted V and the
other a 3el quad. Both are mounted at near the same
height and fed with about the same length of coax.

Is it normal for the quad to be quieter?

Noise almost always arrives from multiple directions and from different
directions than the desired signal.

It is normal for ANY antenna to be quieter when it is more directional.
As a matter of fact, it is expected that S/N ratio is a direct function
of directivity of the antenna as long as the noise and signal are not
coming from the same direction.

To answer your question, it would be very abnormal if your quad (or
Yagi or any other directional antenna) was noisier than a broad pattern
antenna like your Inverted Vee dipole.

By the way, a real Inverted V is a longwire array fed at one end. I'm
assuming you really have an Inverted Vee dipole, and not a true
Inverted V.

73 Tom