Specifications

SG-231 MANUAL
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
© 11/00 SGC, Inc. P.O. Box 3526, 98009 Fax: [phone] Tel: [phone]
E-Mail: [e-mail] Website: www.sgcworld.com
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poles should be 20 to 40 feet. Supporting poles should be as tall as possible to provide
the antenna with the greatest isolation from industrial noise generated by the building,
such as fluorescent lights and electrical motors. Loop antennas are also less susceptible
to industrial RF noise generated by the building, because they are isolated from the
ground system of the building.
Loop wires are attached at one end on the high voltage active side of the coupler and on
the other end at the groundside of the coupler.
Figure 4.5.9 Base Delta Loop
Radiation
Base Delta Loop
Coupler
The delta loop antennas are ideally suited to long range communications due to their
low angle. This configuration is best for communications ranging from 500 to 5000
miles in the HF frequency range of 4 to 22 MHz. Noise rejection is excellent, as stated
for the quad loop antenna. Because the antenna system is not connected to a ground,
noise rejection is enhanced. If mounted on the rooftop of the building, it is further
isolated from the building, which generates 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.