I got this YEARS ago, might be some use, dont know if its still even valid/current.
XCOM installation in Jabiru powered aircraft
The XCOM radio is ideally suited for light aircraft including those powered by the Jabiru engine, there are however some precautions which are necessary to protect your aircraft avionics, including the XCOM radio.
The Jabiru engine is normally supplied from the factory with a Kubota regulator.
Unfortunately this regulator is not really up to the job of aircraft operations. It is originally designed for use in a garden lawn tractor. In this environment you start the lawn tractor to mow the garden and the regulator only needs to recharge the battery so the next time you go to start the engine the battery is fully charged. In this application and environment the regulator performs really well but unfortunately in aviation use we are simply asking too much from this very basic regulator.
In an aviation installation we are not just recharging the battery as we are in a lawn tractor. In aviation we are running radios, transponders, GPS, intercom systems, strobes, recharging the aircraft battery and most of the time also recharging our mobile phone or some other mobile device when we are flying. In this application the Kubota regulator is really going into trauma because it is being asked to perform outside its design parameters. The first thing that happens is the regulator starts to get hot and from there its simply overloaded/overworked and it starts to put out very damaging voltage fluctuations which can be either high-voltage or low voltage.
These voltage fluctuations are only for milliseconds so they won't register on a multimeter or a voltmeter inside your aircraft but they will be sufficient to potentially damage your avionics. Items like a GPS with an inbuilt battery tend to be more durable because the internal battery protects the device from these fluctuations, items like a radio and a transponder do not have their own internal batteries and are more susceptible to damage caused by these excessive voltage fluctuations.
There are several precautions which you can take in an effort to try and get better performance from the Kubota regulator.
Firstly, try and keep the regulator cool. You will notice that the regulator has fins over the top to try and dissipate some of the heat, make sure the regulator is in good cold air flow, keeping the heat down will also help in reducing regulator problems. When you restart your engine after having not flown for some time give the regulator a chance to recharge the battery before you start to turn on all of your additional instrumentation including items which draw a lot of electricity like a transponder and strobe system.
Finally, look at replacing the Kubota regulator with a more suitable unit made specifically for aviation use. There are a number of these available on the market from aviation businesses like Aircraft Spruce and others and we also recommend looking at the PowerMate voltage regulator which is suitable for most LSA type aircraft installations.
The PowerMate regulator can be purchased directly from our website or from the website of the manufacturer, please visit http://www.powermate.com.au for more details.