Irregular Verbiage
from the desk of Colin Nicholls

Blueprints using Google Sketchup

January 2, 2010 19:35 by colin

Google Sketchup is pretty amazing, for a free program. You can build up 3D models of things using primitive shapes, putting them together, zooming around and rotating, and even dimensioning. It's tricky to use, but there is some valuable tutorial videos that explain things one tool at a time.

Here's the workbench I'm planning on building:

I'm sure the free version has limitations (I must try printing, for example) but so far, it's awesome.


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I am a fricken' electrical engineer

January 2, 2010 16:59 by colin

This post is dedicated to my Dad.

A couple of months ago, our Panasonic DMR-E85H digital video recorder died. It did this once before, several years ago, and we took it to an official Panasonic repair facility where they did something to it and charged us about 50% of the cost of the original purchase. We kind of agreed that next time it died, that would be it, and we'd have to find a replacement.

It turns out that "they" don't make them any more. You can't buy a new device that records TV shows to hard disk, without involving a subscription, either to the cable company (who want to give you a cable decoder+integrated hard disk recorder) or to Tivo / DirectTV / SatelliteTV company. Screw that. According to the manufacturers, "customers are not asking for such devices". That's bullshit. I simply don't believe it. It's my believe that there is a corporate conspiracy going on between the media networks and the hardware manufacturers... but that's a different rant blog post.

After some research, we found that second-hand Panasonic and similar units are commanding quite extraordinary prices. The nearest thing we found was a refurbished Philips DVDR 3576H, on overstock.com. At first glance, it has similar specs, although with some trade-offs:

Positive: The Philips has a built-in ATSC digital tuner. This means that, if we were located somewhere with line-of-sight to a HDTV transmitter, we could attach an aerial to the recorder and record free-to-air HDTV programs. (This is not currently feasible for us, living in a valley in the North Bay, not without some experimentation, for another time.)

Negative: It does not have a way to tell the cable television decoder box to switch channels. The Panasonic had an IR-Blaster, but the Philips does not. This means that, although we can set up a recording schedule on the recorder, we must manually set the channel to record on the cablebox. This is not "set it and forget it" by any means. If we want to record two shows on different channels on the same night, I basically have to set an alarm to remind me to go point the remote at the cablebox and change to the appropriate channel.

Also - the operating system on the Philips device is HORRIBLE in comparison to the Panasonic, which itself was no great thing of beauty.

But this post isn't about the Philips. It's about the Panasonic DMR-E85H. You see, I didn't want to break it down or recycle it. I wanted to fix it.

My first thought was, OK, it's completely dead, therefore the power supply has perhaps burned out (they have a known issue with overheating). I opened it up, and a visual inspection revealed no obvious component failure. So I got out the trusty multimeter, powered up the unit and tested the voltage rails. They had voltage! Drat. Without the technical manual, or an oscilloscope, or more sophisticated equipment, I wasn't going to get much further. I closed the unit up and packed it away and grumped for a week.

Then I found this thread on avforums.com. This is a long-running thread (from 2006) and, after reading it all the way through, I concluded that there were still some things I could try. The most obvious problem was a failing voltage regulator, but it could also be failing electrolytic capacitors. It was worth opening up the unit and removing the circuit board of the Power Supply Unit (PSU) and giving it a closer examination.

(I wish I could say that I would have done this regardless, but the truth is that the posts on the AVForum thread gave me the confidence and incentive to try it.)

I was half-way there already, because the PSU board is located underneath the hard drive - I had to mostly disassemble the unit just to check the voltage rails. Removing the board was an extra step: four additional screws and disconnect one ribbon cable.

Breaking out the magnifying glass and reviewing the board revealed an obvious problem: Swollen and leaking electrolytic capacitors, just behind the voltage regulator:

There were three of them that looked suspect. Now I had a plan: replace them! Using solder braid and my trusty soldering iron, I carefully removed the suspect devices.

I had some trouble obtaining replacements of similar size, but Electronics Plus in San Rafael had some that might fit. (Using over-spec'd voltage rating on caps is not a problem, providing they fit inside the chassis.)

After creatively arranging the larger capacitors on the circuit board and soldering them in place, I was ready to put it back together. Crossing my fingers and holding my breath, I powered it up:

It's a little hard to see, but yeah, it worked. (does happy dance)

The Panasonic is now back in our living room equipment shelf under the television, recording shows and changing channels on the cable box via its IR-Blaster. The Philips will be relegated to our bedroom.


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Stand by

January 1, 2010 12:14 by colin

I've got two or three posts buffered up in my head but I'm thinking, seeing as it's 2010 and all (blood rushing to head as I type) perhaps I should try upgrading to BlogEngine 1.5 for the new year. And maybe re-enable comments too.

 

 

UPDATE: Awesome. Rocking into 2010 on BlogEngine 1.5. Hopefully the blog spam workaround is in place in this version and comments will be available. Here's hoping.

UPDATE #2: Comments don't seem to be working on the hosting site. I just see a rotating GIF thingy and the comment doesn't appear to be saved. This is probably my fault. On the other hand, comments work just fine locally.

UPDATE #3: Thanks to some help from Ben on the BlogEngine forum, it looks as though comments are back in action.

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A frosty morning

December 25, 2009 14:24 by colin

Taken a couple of weeks ago: Frost melting on the, um, plants, alongside our driveway. 


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Another colourful visitor

December 24, 2009 23:13 by colin

I don't intend this blog to become a bird-watching log, but we do get some colourful visitors in our backyard. A couple of days ago, this interesting character showed up:

 
(There weren't three of them - it's just some creative photo-manipulation). Originally he was underneath the birches, posing perfectly for the camera, but by the time I decided to go and get the camera to take his portrait, he'd moved further back towards the fence, and was working his way along the edge of the lawn poking his beak into the ground to look for insects, I guess.
 
 

 
A quick perusal of the Pacific Coastal Wildlife Regional handbook indicates that our visitor is most likely a Red Shafted or Intergrade Flicker. He's "the only woodpecker regularly seen on the ground where he feeds on Ants, etc". 

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Imogen Heap @ In the Venue, Salt Lake City, Nov 2009

December 10, 2009 16:17 by colin

What do you get if you cross Thomas Dolby with Suzanne Vega with a touch of Peter Gabriel? I've no idea but it might sound a bit like Imogen Heap.

Ms. Heap is a master (mistress?) of lyrique-concrète, sprinkling her songs with fragments of found conversation, and accompanying them with a tasty mix of high-tech synthesiser multi-tracked goodness and low-tech sampled household objects, tied up with competent acoustic piano and arrayed on a score of quirky harmonics and the best middle-eights in the pop music genre.

We were lucky enough to see her in concert on her recent U.S. mini-tour, in Salt Lake City.

It was totally awesome. There are many video clips of the concert on YouTube


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RIP Kami, First Cat (since Feb 2006)

November 26, 2009 16:25 by colin

 

The trees are quiet; the birds have no-one to tease.
The Sun still streams into the den to tickle the rug; but no cat enjoys it today.
Yesterday, a long-time companion, worn-out, rested her head on her paw, in comfort at last.
"I'm never getting up again!" she said blissfully. And she was right. 


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Be very very quiet

November 8, 2009 15:32 by colin

I went out into the back yard this afternoon and stood on the grass and just contemplated the sun and the breeze and the smell of the back garden. Then I noticed that, after a while, different birds would fly into the little copse of birch trees in the middle of the lawn, and pay me no heed. I sensed an opportunity... so I went and got my camera, and then returned and stood on the lawn, waiting. Pretty soon I could hear the tap tap tap of a woodpecker:

 
I think this guy is a male Hairy Woodpecker.

A little while later, a hummingbird buzzed around me and paid attention to the trunk of the nearest birch. I took three decent pictures of her, and I've tried to combine them in interesting ways below:





What was she so interested in? There were no flowers there. I took a look:



Aha. The woodpecker has been drilling through the outer bark, and the hummingbirds seem to enjoy the sap as it oozes out. This would be charming and all, except that I'm a little worried about our birch trees:



It's beginning to look like some serious damage. I guess this is a seasonal activity, and has probably occurred often in the past, but I can't help feeling nervous about it. We love our birch trees!


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A Morning Visitor

November 4, 2009 10:23 by colin

 

This little guy showed up on one of our birch trees this morning. I snapped some pictures of him through the living room window: 

 

 

I would have thought he is a Ladder-backed Woodpecker or a Nutall's Woodpecker but he seems to have more red on his head/breast area than the pictures of those two species I've seen. He does match the description of a Red-breasted Sapsucker (Sphyrapicus ruber) however.

 


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The best ideas are taken

October 23, 2009 10:12 by colin

So I was reading about all the remote-controlled "robot" predator drones flying around in Afghanistan and wherever, and it occurred to me that it would be a good story if an altruistic arms manufacturer started selling superior robotic war machines. Of course, eventually all the major powers would be fighting their battles "by wire", and after some years it would be revealed at the end of the story that all battles currently being fought were in fact being fought virtually with no actual presence in the real world.

Someone more talented than me has no doubt already written such a story.


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