Grounding it probably won't change things very much on 15 meters, especially
if this antenna is elevated several feet.  Remember that a quarter wave of
wire on 15 meters is only about 12 feet, so that if your ground wire is that
long, the impedance at 15 meters at the top end of that 12-foot wire is
high, rather than the low you wanted.

You may need to work with the power company or the neighbors in identifying
and eliminating noise sources.  If you hear power line related noise on your
vertical on 15, the noise source is probably within 200 feet, perhaps much
closer.  It is easiest to identify noise sources by putting the receiver in
AM mode, for the standard power-line noise, or reduce the RF gain and tune
across on SSB to see if there are any peaks and valleys in the spectrum of
the noise, which may indicate that it is from a switching power supply or
other medium-frequency source.
73,
Lloyd Rasmussen, W3IUU, Wheaton, Maryland
Home:  http://lras.home.sprynet.com
Work:  http://www.loc.gov/nls
 
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Howard Kaufman
> Sent: Saturday, December 10, 2011 9:37 AM
> To: [log in to unmask]
> Subject: imax-2000 continued.
> 
> As I would have suspected, the imax is a great transmitting antenna.
> Receive is not as good.  True, if I can hear it I can work it, but the
> noise
> floor is higher.  I am wondering if I ground this mast to an earth ground,
> if that will help.  The noise is a constant s8 on fifteen meters.  The
> vertical doesn't get out well on 20, but is s units better than the zepp
> on
> 17 and up.  I have never used a vertical before.
> H T Kaufman MSW LCSW
> Adaptive Technology Instructor