Samsung NC10 Power Supply

First of all I must recommend a site for all Sammy Lovers, I discovered it a bit late, I had made my decisions on what was the best Netbook around and solved the problems, well nearly all of them, no one seems to have all the answers yet.

http://www.sammynetbook.com/news.php has a lot of members all of them just luuuve their Sammy and there is a lot of expertise on hand.

A user on Sammynetbook.com mentioned that his wife got shocks from her Sammy, a case of His and Hers Sammy’s in that household, lucky people. He got no such thrills from either His or Hers.

I am still waiting with interest on some tests suggested, swapping Power Bricks etc. However I think that there is nothing to worry about, Induced Voltages are a fact of life. Other users have confirmed slight tickles from their Sammy too.

I measured the DC Output of my Sammy Power Brick with a DVM – 19.1 Volts. Then I looked at the AC Voltage from the Negative – Sleeve of the Power Brick to Earth (real Earth) – 69.2 Volts RMS.
I was not surprised by this figure all sorts of mains powered devices can give you a tickle to Earth due to Induced Potentials.

In order to confirm that there was nothing unusual in the Sammy results I checked the Wall Wart Charger for my Sat Nav. – 69 Volts AC from Sleeve – Negative to Earth.

I wondered what the AC waveform looked like so I hooked up the old Telequipment D54 scope and took a look.

First the ripple with the PSU plugged in but switched off as the reference.

Next I looked at a Wall Wart which uses conventional PSU techniques (transformer). There was around 20 Volts Peak to Peak of 50Hz ripple to Earth.

Next the Sat Nav Switched Mode Wall Wart. A rather spiky chopped waveform but surprisingly 50Hz, I expected to see more of the evidence of the switching frequency. The Amplitude is around 130 Volts Peak to Peak.

 

Finally the Sammy Power Brick an almost identical waveform and Amplitude.

 

Being an Induced Potential it is not going to be of any danger to users. I looked at the current capability to Earth, DVM 20mA AC range, as expected a flick of digit upon connection sometimes but no measurable Current at all, I assume a low impedance load will pull the voltage to zero.

Such Potentials could damage sensitive electronics so there is as always a lot to be said for proper bonding and / or isolation of all interconnected equipment.

One thing is certain the DC from the Sammy Power Brick is clean of noise, I understand that some Laptop Supplies kick out so much interference that they can wipe out broadband.
Also I have it on good authority one of the Asus EeePC supplies created so much noise that it spoiled communications applications.
A further great advantage of the Sammy is that considerable periods of operation can be had from the battery supply thus eliminating any chance of mains borne noise.

Incidentally I notice that back in December 2008 there were Amateurs who were Sammy lovers, users on the Ham Radio Deluxe site, well I had fun pioneering all alone. Why do we find out these things too late despite a thorough research on the web.

Wind and Solar Power and the NC10

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.

The Sammy and Linux

I have spent a little more time looking at Linux on the Sammy. Ubuntu 8.10 boots up fine, I did a quick test initially, just to prove to myself that it would work.
After a little research it seems that Ubuntu 8.10 does not support the Atheros WiFi ‘out of the box’. No problem the driver is available and easy to install, however it seems that every time Ubuntu updates it undoes the work you have done and you have to re-do from start. Still not too bad but hey, it seems Fedora 10 works out of the box according to reports.
It is not just the Wifi support that is better other support is covered too. So yep of course I have tried it.

This blog is posted using Fedora 10 the capture is of the Sammy desktop. Good another step completed, we are ready for super safe browsing on open networks.

The Sammy on 12 Volts DC

Following the comments from ‘balmaha’ on my previous post, (he won’t last long now, another Sammy sold) I have today gone the full mile and purchased the Maplin Car Laptop Power Unit I mentioned.
A very good buy at the current offer price, rated at 150 Watts it slumbers along on the Sammy. It has been on for 3 hours and still feels cool.

Measuring current when the connection is a Cigar Lighter Socket is not easy so I am using my DC PSU meter as the not highly accurate instrument. When charging the Netbook Battery the current is slightly less than 2 Amps by the look of it and just over 1 amp once the cells are charged.
I have not gone for critical power saving settings, back lighting is at mains power level, performance full, USB GPS powered on, Wireless Internet on and connected and Bluetooth on too.

This gives me a portable radio set up using the FT-897 with a total current consumption of around 5 Amps on TX. Mind you on WSPR for an output of 1 Watt, 69 Watts consumption is still pretty disgusting.

Incidentally internal Battery powered I viewed a few videos on Youtube, tried out the GPS on a stroll up the road, slung the Sammy on chair still switched on while I ate lunch picked it up an hour later and the battery indicator said 6 1/2 hours use left. One day I will have time to run it flat.

Personally it gets my back up when people avidly support junk just because they made the mistake of purchasing it, for instance the Icom IC706.
So do not take my word for it take a look at the views of 799 other purchasers here PURCHASER REVIEWS.

The Telegraphers Bathroom

Some thing I have thought of doing for years. The Hot and Cold decals wear off on even costly taps in time. A White Stick operator would have no idea of the correct tap for hot using the usual engraved versions, unless there really is a convention for Left and Right.

My plumbing follows the physical convenience of the pipe run. I have just refurbished some basin taps (new insides).

A Morse Code H for Hot is easy, paint filled indents can be felt in the dark. Cold presents a problem a C in Morse Code is too complex. So I used an I. Cold Ice get it? I reckon there might be a connection in Ancient Latin there somewhere.

I could have made the I blue and the H red for kids and others, but NO, learn a bit of Morse or get the wrong product. There is a logical value code in there too to my mind, Hot is >than Cold.

Well it might also make a talking point for visitors.