Wednesday, November 30, 2011

Australian PV Solar Energy Exhibition

Today I visited the Australian PV Solar Energy Exhibition at Darling Harbour in Sydney.

There were a lot of Chinese PV Solar cell manufacturers on hand and it seems like wholesale prices are diving to an incredible 77 cents per watt (we pay around $5 per watt retail so there's a good margin somewhere).

Interestingly, polycrystalline panels seem to be almost as efficient as monocrystalline and the extra area due to them being rectangular may be the reason.

The gentlemen at Alco Battery Sales were very kind and patiently answered a bunch of questions I had.

Something seems to have gone wrong with the show's timeline and apparently about two-thirds of the Chinese exhibitors didn't get time to clear customs to allow them to attend so it was much smaller than planned.

Several of the manufacturers commented that the withdrawal of the NSW solar rebate scheme had impacted them in a very negative way along with the instability in Europe. Happily, Germany, which has the largest solar program remains strong.

The standout in the show for me was the LED lighting, which I believe will take off in the next twelve months.

Above is a demo showing an incandescent 40W bulb producing the same output as an LED replacement using less than a tenth of the power. LED lights last much longer and in summer there are also savings in the need for air-conditioning.

Awaiting approval are 240V bulb drop-in replacements, 12V AC halogen replacements and 240V fluorescent tube replacements (you remove and bypass the starter).

Monday, November 28, 2011

A talk about setting up a small solar power system

At Sunday's Amateur Radio NSW Home Brew Group meeting I gave a talk about what I've learned about low voltage solar electricity systems.

My thanks to Peter, VK2EMU, for the opportunity to speak and to John, VK2ASU, for shooting the video.

If you find this interesting and want to know more there is a book "Small Solar" available for less than $3 from Amazon for the Kindle and in the Apple iBookstore for iPad.

Sunday, November 27, 2011

Back on WSPR on 20m but not on Windows

I have an MSI U-200 netbook that dual-boots Windows XP and Linux. For a long time I used Ubuntu but when I upgraded to 11.04 wireless networking wouldn't work and being unable to figure out the magic incantation decided to try Fedora.

There's no built WSPR for Fedora that I could find so I've been running it under Windows XP. Lots of people were spotting me (running under 5W from an ft-817) but I got no decodes of other stations at all. This morning I checked out the WSPR source and built it. All of a sudden I'm receiving lots of stations.

Ubuntu has been good to me but I found the switch to Unity a little premature and, quite frankly, Gnome 3 has all the good bits as far as I can tell and seems a lot more complete. It's weird that a desktop could ship without a simple way for a user to add a launcher to the dock (or whatever it's called).

Can't explain why I get no decodes on Windows. Perhaps the sound card is not right?

Thursday, November 24, 2011

Learning iOS 5 programming with Paul Hegarty

When I need to do a bit of Cocoa programming I normally turn to the excellent books from Big Nerd Ranch. iOS 5 and Xcode 4.2 has changed normal practice quite substantially and I was struggling along trying to re-interpret the old code in the new environment.

A couple of days ago the latest videos of the Stanford computer science class covering iPad and iPhone App development turned up in iTunesU.

This course presented by Paul Hegarty is fantastic. It's a best case example of good teaching by a master of what he is presenting. Even the questions from the class are spot on.

I've just got to lecture 4 which took place the day after Steve Jobs died. Paul gives a nice tribute and talks about the years when he worked at NeXT and how Jobs valued the aesthetics of things so much that FMRI scans of iPhone users match up with them feeling love (rather than the expected addiction).

He ends each lecture with "if you have any questions... I'm here."


I'm still ploughing through these lectures and continue to be super-impressed with Paul Hegarty's teaching style and overall knowledge. It's wonderful that Stanford feels comfortable to release lectures of such quality for free to the public - great stuff, a credit to everyone involved!

Humbly, I'd like to propose some constructive feedback:

  • The slides are sometimes very wordy - fine when it's code, but often just descriptions that could be shortened.
  • Sometimes it's hard to read the code shown in Xcode, it ends up being rather soft, perhaps there is a more video friendly font?
And, an Apple TV complaint. The damn thing over-scans and I can't find a way to turn it off. So I lose the menu bar on my TV. I know it's there in the movie if I look in iTunes but you can't see it on the TV. The overscan is not in my TV.

Thanks Paul Hegarty, you are doing great work - thanks for sharing.

To be specific, here's a wordy slide example:


Eight months after this post, I have two apps in the store by me and am now a full time iOS developer for a major media company which publishes a large number of apps. I'm loving my work and continue to learn more each day about iOS programming.

Tuesday, November 22, 2011

HP Laserjet 1022n prints every second page

A note to myself really. We have an old but reliable HP Laserjet 1022n laser printer but ever since Snow Leopard it has been printing every second page, with a blank page in between. I used a generic CUPS driver but the quality is very poor.

I've found a solution for me, that might work for others. If you set the printer's resolution to 600dpi it seems to print all pages and the quality is good. Here's how the setting looks in the print dialog box:

I've saved this as a preset so it comes up by default every time and has worked for me for several months now. This problem has many threads in Apple's support forums and HP's boards so I'm not alone. Hope it helps someone else.

Sunday, November 20, 2011

QRP Portable at Fisherman's Paradise

Just returned from a weekend away, four hours south of Sydney at Fisherman's Paradise. Here's my QRP portable station:

My antenna was a random wire, about 6m long, thrown to a tree from the balcony.

The ZM-2ATU antenna tuner does a fine job with a random wire and a counterpoise and never fails to tune up easily.

Fine copy on the WIA Sunday broadcast on 80m, 40m but best on 30m. I called back on 30m and while the VK2WI station couldn't make me out a few other stations relayed my presence. VK2BGU, VK2BGL, VK2JE and VK2HL were all very strong to me.

Local birdlife came to listen in and stayed for some snacks:

After lunch we went for a walk among the mosquitoes and looked at the local boats.

Back in Sydney and a big week ahead.

Thursday, November 10, 2011

Insulated the metal shed roof for summer

The shed has been marvellous so far, but as foretold by mates Gerald and Ralph, the weak spot will be heat from the sun beating on the corrugated metal roof.

Indeed, when the sun is on the roof, it's like a radiator inside. I purchased R3 poly bats, which I had to split in half so they're around R1.5. Backed and held in place with masonite board. It now looks like this inside:

It's a pretty rough job but the effect is a huge improvement in comfort when the sun is beating down. Foolishly I went along with the offered skylight and of course this isn't desirable in full sun so I've placed the 65W solar panel over it and it covers it pretty well.

I could go on and insulate the walls but wood is a pretty good insulator already so I think the most important job has been done.