In mobile operations, the biggest problem you will run into will be noise. Although
noise is often found in fixed locations, the mobile environment, including marine
applications, noise sources can vary, depending on the engine speed and other variables.
Noise and its removal are covered further in this user guide.
Not much needs to be said about solar charging systems, except that good design practice must be followed to
provide reliable operations under all conditions that you could expect to be encountered.
The most critical element when designing an HF solar power system is to know about the local weather
conditions. If you are designing a solar system for an area where there will be little sunlight for many days in a row,
then a large battery system and additional solar panels will be necessary. On the other hand, if you are designing
the system for an area where there is a lot of sunshine at all times of the year, then you will need fewer panels. In
some cases, two 53-watt panels and one good rechargeable gel cell battery will be sufficient.
Seasonality must also be considered. Obviously, in the high Arctic, solar power is ideal for the month or two
during the year when the sun never goes down. But in the other months, solar power is just not feasible. Hence,
another consideration should be the latitude where the solar system will be installed and a calculation of the number
of hours of daylight that will be available during the shortest days of the year.
The type of regulator that is selected to control the output of the solar panel(s) is very important. It should
operate over a wide range of loads and should continue to provide trickle charging to keep the battery system
charged to its fullest between operating sessions.
Human-powered chargers are only suitable for low-power transmitters that are in the 20-watt class and under,
such as the SG-715 manpack. Human-powered chargers will only supply a few watts of power on a continuous
basis. However, when they are used in conjunction with a battery, they provide a good means of recharging when
solar panels are not practical and other sources of power are not available.
Human-powered chargers are usually in a "coffee grinder" or "ice cream crank" configuration and are used by
one person at a time. They are not typically included in an HF installation. However, human-powered chargers are
often used for backpack transceivers in the field or in instances where periodic access to conventional re-powering
sources are not available. In amateur radio applications, modified bicycle battery chargers were a somewhat
common novelty during the early years of consumer solar panels, in the mid to late 1970's.
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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.
SOLAR-POWERED CHARGERS
HUMAN-POWERED CHARGERS
Noise is the biggest
problem in mobile
operations.
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