This is why when you are putting up a base station antenna you should use number 6 or larger wire because you
will get tremendously improved performance.
The next consideration is how the antenna system works. With our SG-303, there are actually two antennas in
a single casing. There is a single rod element, which is resonant at about 22 MHz, and there is the helical wound
element which is resonant at about 13 MHz. This means that on lower frequencies, those under 20 MHz or so, the
SG-303 will vastly outperform other antenna systems.
Even when the resonant type of antennas are used, the SG-303 will out perform because a lot of people don't
understand that when you operate a radio system on a frequency higher than the resonant point of the center loading
coil (which is the most common form of loaded antenna), the loading coil begins to act like an RF choke.
So if you set up a marine antenna for resonance in the 3 MHz band, then use the same element to operate at 8
or 12 MHz, the loading coil has just turned a typical 23 foot antenna into about a 5 foot antenna. And this principle
applies to ham and commercial installations as well. When you use a center loaded low frequency antenna on 8 or
12 MHz, you end up with an effective antenna length of less than 2 feet!
When you add up all of those individual dB's and compare them between systems, what you will find is that
there is a tremendous advantage for the QMS system. But when you hear a really big
mobile signal, and we're talking marine, land or airborne, you can be pretty certain that
either the coupler has been done right or the system is operating really close to resonance.
As we mentioned a moment ago, there is no mounting hole for an antenna and no pass
through hole for feed lines with the QMS when installed on a car. This means that the resale
value of a vehicle is held intact.
The QMS houses the tuner which makes the lead from the antenna as short as possible.
And by putting the tuner outside the body of a vehicle, you get the advantage of shielding
from a large portion of internal vehicle noise. This is a major plus on the receive side.
The QMS may be removed and stored in 5 minutes or less, quickly hiding the fact that there is an HF radio in
the vehicle. This quick removal feature is really useful when you are operating in contested frontier areas - or if
127
The SGC Building, 13737 S.E. 26th St. Bellevue, Washington 98005 USA
P.O. Box 3526, 98009 Tel: (425) 746-6310 Fax: (425) 746-6384
© 1997 SGC Inc.
QMS FEATURES AND BENEFITS
The QMS mounts
with straps and
suction cups so
no holes need
be drilled in your
vehicle.
Learn to love
the look!
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