Andy wrote:
I've swapped the feed line over and its still the same.

When I put the antenna together I made sure all connections where good and
the analyser gave a good match on the frequencies I want to use.

I did use some conductive grease for the first time on the antenna. Wonder
if the grease is the problem or maybe this antenna just picks up a lot of
background hiss.

Andy

The instruction manual for the antenna doesn't make it real obvious how
the feedline attaches, but it looks to me like the antenna doesn't have
a low DC resistance - like a loop would, for example. It's probably
reasonable to expect this type of antenna to be noisier than a loop. I
think Butternut attaches the feedline in a similar fashion on their
HF6V, but puts an air core choke (from memory, 15-20 turns, 14 awg,
approx 1" dia x 2.5" long) across the feedpoint. That may just be for
noise because the antenna seems to have the same performance with, or
without it. Perhaps you could try the same with the MA5V.

I think what the OP was getting at is the noise should be a lot louder
with just the center conductor attached to the radio, and then get
quieter when you thread the barrel on. If it doesn't do that, then
there may be a connectivity problem somewhere.

ac6xg