Since the purchase of my Sammy (Samsung NC10) Netbook Computer the Green Power concept for my portable operation will be more fulfilled. In the past the computer use has been limited due to the current required.
At home my Solar Power is merely a token addition to the power used by the radios and computers. When we are 'out and about' we are solely dependent upon Wind and Solar power. The consumption at 12 Volts of the Sammy is around 1 Amp. this brings it into the use as much as you want to category.
The 12 Volts is stored in two 85 Amp Hour Leisure Batteries. The Solar Panel is a 50 Watt unit. Be careful when thinking in terms of rated Wattage and expected Current with Solar Panels. Current is found by dividing the Wattage by the Voltage, do not make the mistake of thinking this will be 50/12 = 4.166 Amps. Manufacturers rate the panel at its maximum Voltage which is maybe 18 Volts, therefore 50/18 = 2.77 Amps is more of a realistic figure. What is more this is the maximum output in full sun, in the winter 0.4 Amps is often encountered at mid day.
My wind power is derived from an Aerogen 4. Again giving direct figures for current output is not straight forward as the output is dependent on wind speed. Suffice to say it can produce 4 Amps in a stiff breeze and 19 Amps continuously in a good 60 knot blow.
The 12 Volts nominal Voltage from the storage batteries is no good for feeding the Sammy direct. I chose the Nikkai A33HU Car Laptop Power Unit (Maplin) to provide the 19 Volts at 2.1 Amps Max. needed. This unit rated at 150 Watts does not even get warm when providing such meagre needs.
One of the most important things a computer has to do for me is to enable connection to a Radio Transceiver and run Radio Communication software. Any computer not capable of this to me is a dead parrot. Yes they can connect to the internet and do all sorts of lovely things but that is via wires and telephone exchanges etc and at a fee.
Connected to a Transceiver it comes to life and whether I am typing on the keyboard or sending coded data or Still TV Pictures the world is at my fingertips.
We can send our position from GPS continually whilst driving (APRS) allowing other users to track us via radio. Using the right software we can send (rather high power) signals to be bounced off the moon around the world. Personally I prefer very low power (QRP) operation. At very reasonable power levels (15 Watts) I like to use the 50 MHz VHF Band (around the frequency of the old Band 1, BBC1 TV) and reflect signals from Meteors.
Some Meteor showers are large, come at pre defined times and are named, these produce the 'falling stars' often seen on dark Autumn nights. What is less known is that there are Meteors hitting the Earth's atmosphere all the time. Some are no more than the size of grains of sand or dust, when they burn up in the atmosphere they produce an ionized trail which is capable of reflecting radio signals.
Having said that I put the Sammy on whilst writing this blog and was getting a little worried that I had had no results. Early afternoon is not a good time and the predictions for meteors are low, however I was not disappointed.
At 14.53 GMT there were several reflections, one burst of signal can be seen in the capture from the Sammy desktop above and a perfect de-code of the signal data. The other station is in the UK out of direct communication range on VHF for me. The same Meteor could have reflected signals from Scandinavia, Eastern Europe, Italy, Spain or Africa.
In the software used there is quite a bit of processing going on, Fast Fourier Transforms and Fortran routines, the sound 'card' In and Out needs to be of pretty good linearity and low noise for this sort of work too.
Can the Sammy do it? yes it can.
