26
not connected to a ground, noise rejection is enhanced. If mounted on the
roof-top of the building, it is further isolated from the building which gener-
ates RF noise.
The supporting mast should be 8 to 14 meters tall to provide good overall HF
performance.
Note that with this type of antenna, the coupler may be mounted in the middle
of the horizontal portion of the loop or it may be mounted at the corner. If
mounted at the corner and the lead from the coupler attached to the vertical
leg, the polarization of the loop tends to be vertical and is slightly better for
low angle long distance communications.
Loops in the horizontal plane may also be used. This type of antenna provides
exceptionally good performance on the low frequency bands for short to
intermediate range communications.
F
Fiig
gu
ur
re
e 5
5..1
10
0
V
Ve
es
ss
se
ell G
Gr
ro
ou
un
nd
dlle
es
ss
s L
Lo
oo
op
p
O
OO
O
P
The triangular loop antenna for sailboats is designed to operate in a ground-
less environment and still provide high performance. This type of installa-
tion will require only one insulator point on the bottom backstay and an elec-
trical connection on top of the mast and stay. The grounded side of the coupler
is connected to the bottom of the mast. Although not our best recommenda-
tion, this antenna will provide a workable solution in some installations.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA
P.O. Box 3526, 98009 Fax: 425-746-6384 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: [email protected] Web site: http://www.sgcworld.com
© 1998 SGC Inc
SG-230 Manual
Radiation
75 feet
Porcelain
isolator
Lower mast connection
to coupler RF ground
Vessel
Groundless
Loop
Coupler