Tuesday, October 26, 2010

Wireless Networking in the Developing World book

At lunch I was browsing through some old email and was reading some "help me learn about OLSR" type conversations.

There was a link to the book; Wireless Networking in the Developing World

Its now in second addition and in now translated to more languages, you can download it or buy it.

It has been a while since I have setup up new WiFi infrastructure. My network at home has been pretty stable. I should go see whats new in the second edition...

73, Kim

Sunday, October 24, 2010

National Field Day 2010

Yesterday being the National Field Day - NFD for 2010 in VK (Australia), I spent with the Adelaide Hills Amateur Radio Society.

AHARS setup a tent at the Eden Hills Primary School Strawberry Fair.

A number of contacts was made on HF and 2meters and 70centimeter. Some contacts were made through the cross band repeater on the project horus ballon, launched to coincide with the NFD.

I spoke to about a dozen people across the day and handed out pamphlets. That doesn't sound like many people, but there were at least six club members there across the day, who each spoke to members of the public across the day about Amateur Radio and the club activities.

There were a couple of themes across the day for me. The main one was the grey nomads, who use the travelers nets to update their location and journey progress with their net controllers, mainy for safety, directions and recommended stop overs. Folks who use UHF CB and or the four wheel drive net VKS737 already. It was interesting to see them explore the options that Amateur Radio could give them. Even if it was only a couple of more bands to listen to the various travelers nets and listening to the reports coming in about traffic congestion, etc. Its not something that I've really put a lot of thought into, but certainly created an awareness for me about how folks outside of amateur radio use radio and why.

Secondly was the HF verticals and how to set them up with automatic tuners, especially across multiple bands. I believe the original squid pole article was from VK3JJ in AR, but I will have check that. A few of the AHARS club members present had built up the JJ antenna and all spoke about issues with tuning and assumptions with measurements and materials. There is certainly a lot of room for experimentation and of course careful measurement - a topic that comes up so frequently, which of course lead on to the third theme for me... upgrading my license.

I spoke to several folks about upgrading my license, the study involved and stratagems for learning. All duly noted. I will be pulling my finger out over the summer break.

I bumped into a few old friends, picked up a few books and plants at the fair. Saw a new part of Adelaide that I hadn't seen before. Over all, even with a little sunburn, I enjoyed the day.

73, Kim

Sunday, October 17, 2010

Copper cactus J-Pole - part 1

For some time I've been wanting to get a decent antenna up for 2 meters. We have a good technical 'net on a Monday night by the AHARS guys. I used to regularly join in but my little HT's batteries died and it doesn't work without them. I do have a little 1 watt Kenwood rig and a 4AH 12volt battery, which works a treat. However the antenna situation is letting it down. It works quite well on receive, but I need to get the antenna up much higher to activate the repeater.

Quite some time back, I was given some scrap aluminium and a 2 meter slimjim. I used the slimjim alot. It was pretty fragile and I repaired several breaks from wind damage, but its just not very practical as a portable antenna for the rallies, eg ROSA or as a home base antenna.

Lots of digging on the Internet yielded lots of info on the copper cactus antenna. I didn't have any of the common materials, so a visit to the local hardware stores didn't have any hard drawn copper pipe either. Well, Home Hardware had six meter lengths of 1/2" for $98 and did not cut off lengths either =( I decided that a copper cactus was going to be out of my reach and put it off.

Then I picked up a little dual band 2m/70cm 3/8" screw on to mag mount antenna for the car, just before the rally. Its ok pootling around on the car, but with out any ground, it doesn't perform on the little Kenwood at home as well on receive as the rubber ducky on the HT. Its pesky to setup and use at home.

That was all some eighteen months ago. Since then Bunnings has opened and some of their stuff is cheaper than the other hardware stores. Bunnings also has more range, but quality varies greatly. However, they did have 1/2"/15mm and 3/4"/20mm hard drawn copper pipe, but only in 1.5 meter lengths. The HDCP 20mmx1.5m is $16 a length, with 20mm 90 degree bends $2, 20mm Tees $3 and one bag of 1" clamps/brackets $7. So last weekend I needed to get some other things from Bunnings, so I got all the bits I needed and some spare for future projects.

This evening I worked out the measurements and cut up, then sanded the pipe, bend and tee joiners. I have a little industrial hair dryer, which gets everything up to temperature and soldered the lot up.

What remains is the mounting to little mast and getting some coax set up to the clamps. Obviously matching and endless tweaking =)

Can't wait to get the antenna up and tested.

72, Kim

Wednesday, October 13, 2010

SolderSmoke 126.mp3 is out

Yes, thats right, SolderSmoke is back \o/ Head on over, download, listen and enjoy. Damn just got up and have to hop on the bus right now, but I'll be listening to is ASAP!

SolderSmoke 126.mp3
October 11, 2010
SolderSmoke returns!
Shack #7: The New Shack
Drake 2-B inhaling RF
Listening to 75 AM and SSB: WA1HLR, KM1A
Time signal on 3820 +/-?
Repairing DaVinci Code QRSS rig
UK test gear works fine on this side of pond!
Computer woes: First Linux SolderSmoke
Astronomy from inside the Beltway
Winter SPRAT: Great info, philosophy, inspiration
Charging up solar cells
Inbound Boatanchors: DX-40, DX-60, HQ-100, HA-600(A), HT-37

Tuesday, October 12, 2010

Friday, October 08, 2010

Web Cams for Linux

So as a result of a friend asking me about web cam support under Linux for a computer vision project, I found some interesting resources that I thought was worth sharing.

The Linux UVC driver and tools web site lists a couple of really cheap web cams like the Logitech Quickcam C150, which we can source locally for $18 at MSY.

So, some solid state storage, a usb hub and a tiny home server or decent wifi accesspoint with usb would be ideal for this project =)

73, Kim

Sunday, October 03, 2010

Interesting power generation projects from the crew of HackerSpace Adelaide

Paul, VK5FPAW, after a challenge from the Adelaide HackerSpace crew, has bee putting together a pedal power rig to power his HAM radio rig for the WIA WIA National Field Day on the October 23rd. Perhaps other HAM radio contents too, like the WIA Spring VHF-UHF Field Day is on November 20th & 21st. More events on the WIA Calendar.

Over at; http://picasaweb.google.com/pschulz01/PedalPower, Paul has a few photos of his pedal power rig. The stationary trainer is a nice way to mount everything. The alternator is a 50A Bosch. So far Paul has spent about $250.

I'm looking forward to hearing Paul, VK5FPAW/StationaryMobile on air on the field day ;)

73, Kim

New warning system for solar storms

From the WIA broadcast news this morning;



Researchers at the University of Bradford located in the United Kingdom say that a new method of predicting solar storms that could help to avoid widespread power and communications blackouts has been launched. Amateur Radio Newslines Norm Seeley, KI7UP, says that up to now, solar weather prediction has been done manually with experts looking at 2 dimensional satellite images of the sun and assessing the likelihood of future activity.

But a team from the university's Centre for Visual Computing has created the first online automated prediction system using 3D images generated from the Solar and Heliospheric Observatory or SOHO satellite.

Already in use by both NASA and the European Space Agency, the Bradford Automated Solar Activity Prediction system also known by the acronym ASAP identifies and classifies sun spots and then feeds this information through a model which can predict the likelihood of solar flares. The system is able to accurately predict a solar flare six hours in advance and the team is working to achieve a similar accuracy for the prediction of major solar eruptions in the near future.

Solar storms involve the release of huge amounts of hot gas and magnetic forces from the surface of the sun into space at around a million miles an hour. The next major solar storms are expected in 2012-13 as part of the sun's 11-year weather cycle. A 2008 US National Academy of Sciences report estimated that modern reliance on electronics and satellite communications means a major storm could cause twenty times more economic damage than Hurricane Katrina.

Although major solar eruptions and coronal mass ejections normally take several days to reach the Earth, the largest recorded in 1859 took only eighteen hours. Solar flares which can also cause significant disruption to communications systems take just a few minutes. Because of this, advance warning is of vital importance to enable steps to be taken to avoid the worst effects of such solar activity.

Data recovered from the system is on-line at the European Spaceweather website;


The VK5 News: 3rd October

Saturday, 23rd October; National Field Day @ Eden Hills Primary School, Strawberry Fair
Sunday, 7th November; AHARS buy and sell
2nd, 4th Friday; Lunch Blackwood RSL
JOTA 16th
More at; http://www.qsl.net/vk5bar/
VK5KC David

9,10th foundation license
23rd October, Nat Field Day
20th, 21st November foundation license training
QRP CW @ Rostrevour Tennis Club
More at; http://www.sa.wicen.org.au/
VK5PH Paul

Friday 15th October; Meeting at the Reedbeds; Talk on coax cable, types, suitability, tools included
More at; http://www.areg.org.au