Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.
Issue link: http://experimenter.epubxp.com/i/96284
Un d e r t h e C o w l able to use automotive equipment, which was commonly done in years past. However, if you buy a new Cessna today, it will be a 28-volt system. Anyway, the result is that almost all small planes (approximately 350,000 airplanes) are 14-volt systems, while commuter and airliner types are almost all 28-volt systems (approximately 40,000 airplanes). That means there is a much greater demand for 14-volt accessories, so they command a higher price when sold used. Usually the premium is on the order of 15 to 20 percent higher, not double, but it depends on the item and its desirability. (Capitalism at its best.) Another consideration is the voltage required for the avionics you will want. Some of the newer equipment will operate on either 14 or 28 volts, but most of the older generation radios require either 14 or 28 volts. For instance, the popular King KX-155 Nav Comm comes either in 14 or 28 volts, but not both. Interestingly, a used 28-volt version is usually cheaper because most people do not use it. Another popular unit is the Garmin GNS-430/530. Early versions required 28 volts for the radio portion but would operate the GPS portion on 14 or 28 volts. I had to buy a 14 to 28 up-converter for about $350 to make my used GNS-430 work. The newer Garmin units do not have this restriction. There are power converters you can buy if you have a 28-volt component that you want to install in a 14-volt aircraft and vice versa. For instance, the Ameri-King AK-550-6C costs $328 from Aircraft Spruce and will boost 14 volts to 28 for 6 amps. Higher-amp converters cost more, obviously. Down converters, 28 to 14, are cheaper, such as the 9-amp AK-551-9 for $189 from Aircraft Spruce. Also driving the market is the fact that it is less costly to install 14-volt accessories in a 28-volt plane than vice versa. Another consideration is the voltage required for the avionics you will want. Some of the newer equipment will operate on either 14 or 28 volts, but most of the older generation radios require either 14 or 28 volts. These factors are the prime reasons why used 14-volt gear is more expensive than used 28-volt avionics gear. 34 NO. 4/ DECEMB ER 2012