Tjilpi

Tjilpi Tops Google Charts

In less than two weeks since being resurrected Tjilpi has topped the Google Charts in Popularity!

Now, simply by going to Google, and typing tjilpi or TJILPI or Tjilpi you too will be able to access the Tjilpi blog. How cool is that?

And, as a bonus, you'll be able to direct your friends to Tjilpi by telling them to Google it.

It is so easy to find because, once you type in Tjilpi, it is at the top of the Google page. That has got to be cooler than cool! [I did think I had stopped talking like that when I was 18 - but funny things do happen.]

Anyway, all you need to do is remember how to spell the Pitjantjatjarra word for an old man.

Some People Have All The Fun

I mentioned my friend Chris - the Dental Tech in my previous post about my career in electronics. I didn't mention him by name then: but I don't think he'll mind having his name mentioned now.  I knew he would be able to help me out with the tools required to replace broken rubber drive bands in the tight spaces which exist on compact cassette decks.  Only a few days ago I ordered the bands from Wagner Electronics in Sydney.  And then, yesterday afternoon,  I fortuitously ran into Chris in one of the shopping malls while he was buying his young daughter a 'product' from Wendy's.  I mentioned the need for tools.  He said he would arrange something and that he would be in his Lab on Saturday morning.

Chris and I go back a long way, but we haven't seen each other to talk to privately for over a year.  So, as there was no one else in the Lab, and the Dental Surgery next door was closed we were able to "catch up" as he worked.

He was making crowns, by the lost wax method, out of a gold alloy. I knew about the lost wax method of making sculptures - but had never really understood it.  I hadn't realized it was used to make crowns for teeth. 

It is fine work modelling the wax on top of an impression taken from the patients ailing tooth.  The work involves building up what is missing from the tooth and making sure that the resulting crown will fit neatly with the tooth above or below it.  For that reason an impression is taken from the full set (if there remains a full set!) of the upper and lower teeth of each patient. The desk was strewn with molded pairs of Halloween chompers joined by a plastic hinge, allowing him to build up the wax on the tooth, using a tiny spatula heated on a Bunsen Burner.  The hinge allowed him to continually check that the dental occlusion was OK, as if the teeth were fitting together with the mouth closed.

The wax molds of the potential crown were then fitted with a 'sprue', a thin tube of wax which would create a channel for the gold alloy to flow through. [You've probably seen little bits of round plastic projecting from injection molded plastic objects.  It is usually pretty obvious that the round plastic projection is a left over from where hot plastic was injected. Today, I learned that that projection is the remains of a 'sprue' - at least in Dental Lab talk. Maybe you could check out what the plastics people call it and give me a buzz?] 

Once the sprue was attached, the wax molds were removed from the stump on which they were fashioned and put in a special container, with the sprue facing upwards.  They were then invested, or encased, with a quick setting 'cement' made up from a very fine powder and some liquid chemicals.  The cement mold surrounding the inner wax mold was placed in a furnace at 866°C  which is hot enough for the wax to get lost, and if that temperature is maintained, it is also hot enough to allow the gold to flow down the sprue when the time comes.  Chris measured the correct amount of gold required, by multiplying the weight of the wax, 0.5 gram, by 15.2 which was the specific gravity of the gold alloy he was using.  I assisted with this on a calculator.  He needed 7.6 grams of gold and measured some tiny ingots out and put them in a crucible, similar to that on the right. The crucible itself had already been heated to 866°C in the furnace before Chris took it out and placed it on its holder on a large specially designed centrifuge. He then attacked the gold in the crucible with a blow torch driven by a mixture of acetylene and propane. The gold melted, suddenly became liquid, and emitted a firey orange glow.  Chris then took the mold from the furnace and placed it on the centrifuge behind the crucible.  Initially I did not realize that there was a hole in the rear of the crucible corresponding to an opening in the top of the cement mold. Chris set the centrifuge in motion. The crucible and mold spun. I watched the firey glow move around in a circle about three times before the gold suddenly vanished. It had moved through the hole in the rear wall of the crucible and disappeared into the hollow space in the cement where the wax had been. Centrifugal force would lead to displacement of any air in the irregularly shaped spaces inside the cement mold. I danced around with joy saying I hadn't had so much fun in a long time, while Chris told me that he would have to use a sandblaster to get the cement off the gold crowns inside the mold. But he would do that next week, and I was welcome to come back to watch. 

Chris presented me with a supply of discarded dental probes which he had obtained from the Dental Surgery next door to his Lab.  He uses the same probes himself as sculpting tools.  He was happy to help me manufacture them into the shape I would need to replace rubber bands in cassette machines. I'll need a hook at one end and a U-shaped pusher at the other.  He said the blow torch he used to melt the gold was good at softening up the tips of the probes and he has a special set of pliers with which to bend the hot metal into the shapes I need.  "Why not come back and watch me sandblast the cement away from the gold crowns, and we could bend the probes at the same time." 

As I said: Some people have all the fun.

My Career in Electronics

I'm sure I was a good student because I didn't mind sitting at a desk all day. I did it again today.  However, there was a lot of physical movement, mainly from the shoulders down, but at times I almost had to stand on my head in order to get a view of things.

 Today's "electronic" project was undertaken in the spirit of recycling.  Well, actually, the motive was economic. No, I'll admit it, it was purely commercial.  I've been wanting to transfer my old tapes onto CD and, while I have a lot of gear - including a digital recorder which will accept a "line in" from a stereo tape recorder - I do not, at present,  have a functioning stereo tape recorder. I was shown one last week in one of the larger stores in town.  It had twin decks so that dubbing from one tape to another was easy; but I want to 'dub' from tape to CD. They wanted $549 for that twin deck doozy. The young bloke said he could do me a good deal.  I told him that at half the price I wouldn't want it, and said that it reminded me of one I bought in London in 1980. It was the only stand alone tape deck the store had.  Cassette decks are passé and are becoming harder to find. Sometimes I think the big stores dump stuff which won't sell in the cities on we yokels here in the bush, hoping that we are mug enough to buy. 

I used to have two separate functioning stereo tape decks. They were in two Sanyo Micro Component Shelf Stereo Units complete with CD, Radio and Remocon. [That's Japanese for Remote Control.] The models were slightly different, as they were bought about 5 years apart.  I bought one for the office and later, one for home.  I'll call the office machine, A. It was about 13 years old and I found recently, when beginning this enterprise, that both the CD, and tape deck, had given up the ghost.  The other machine, B, was about 8 years old. B recently failed its Cassette deck exam.

With deep regret I decided to sacrifice the near lifeless A.  The radio still worked, but I have lost count of the number of radios I now own.

Thinking back, all I wanted for Christmas when I was ten was a Crystal Set! That Christmas my Dad set me up with one. I have fond memories of my very first radio, and the long wire loop antenna we built in the backyard. Marconi would have been jealous, or proud! After that I went on to build my own crystal sets and even found a ready market for them among my school friends.  While I had no real understanding of radio theory, I continued to build radio receivers from kits, into my early twenties.  A hiatus followed until I was forty, when I began studying electronic theory seriously in order to obtain my Amateur Radio Novice Licence.

But back to the problem at hand.  The technique of opening A was not immediately obvious; although I have had some experience in these things.  I know for a fact that I have pulled more things apart than I have put back together.  I ended up using brute force to learn the anatomy of the exoskeleton of A. Poor A - I've really done a job on it - but there are lots of bits on the circuit boards which will find their way into my 'junk' box for future electronic projects. 

When it came to opening B, I found a difference between the two cases.  In the past I’ve found that Japanese gear usually has a small triangular indicator, or an arrow, which points to the screws one needs to undo in order to take something apart. On A, I found 6 little triangles beside 6 Phillips head screws. On B, I found 8 triangles.  After I undid all 8 screws there was no brute force required on B. Someone in the Plastics Division of Sanyo must have forgotten to emboss two little triangles on the rear of the cabinet of the A model.

With the still useful B machine working, except for the tape deck, I thought, after my study of A, that I ought to be able to change the rubber bands myself on tape deck B, for a broken band was the most likely cause of the trouble. Examination of the A deck revealed that two bands were required, but only one remained. I could find no trace of the broken band. There are slots in the floor of the casing [seen on the right] and the band could easily have fallen through one of those, either recently or years ago, for I had not attempted to use the tape for years.

However, I decided to use the band from the A machine to try my hand at developing my technique for installing new bands if and when I am able to find a replacement set.

In the cross-hair middle of the photo on the left you may be able to see a small pulley wheel on the spindle of the drive motor. I won’t blame you if you can’t see it, though you could try clicking on the photo so that it pops out and is enlarged a little.  I couldn’t see that wheel  for about two hours  while I tried to get the rubber band onto it.  My fading vision was not the only problem.  I was using magnifying glasses and kilowatts of light power.   The real problem is that space is at a premium under the motor. There are only 10 millimetres in which to work. The pulley wheel sits on the ceiling of that space making an approach with a rubber band from underneath very difficult.

When I first opened machine B, I couldn't find the remains of the broken band, and assumed it too had slipped through the floor of the case. However, after I dropped the 'practice' band into the innards of the machine for the umpteenth time, I suddenly saw the old broken band caught up on a plastic projection on the rear wall of the case. Bingo – I had a suspect who could be measured up, so that I could try to find the correct sized replacement. It turns out that the two bands are of different circumference, but each band is square in shape, measuring one millimetre on each side.

There being nothing more to do without replacement bands, I slid the B machine casing back into place. I didn’t put the 8 screws back in place as I'm hoping I'll soon be inserting two replacement bands, and so get on with transferring tape to CD. 

With a twinge of anxiety that I might have ruined something I gingerly put a CD on to play. It worked, as did the radio.

The next job is to Google a source of replacement bands. If I find some I am going to have to visit a friend of mine. He is a dental technician who makes gold teeth and crowns. He has a lot of tools which just might allow me to get into the small space under the motor when replacement time comes.

Thinking of things dental just now caused me to recollect the time my father asked me if I would like to study Dentistry.  I had just completed 12th Grade, and was wondering about courses to enrol in at University. Dad asked me if I would like to do "dentistry or something like that."

I think I would like to do Philosophy, I replied, and he let me. 

It was the time of the Vietnam War and I had completely forgotten about things electronic.  The draft loomed.  Philosophy called.  I often wonder what would have happened if I wandered down a different career path, and had studied Electronics, or something like it. To be honest, I think the mathematics associated with a university course in electronics would have slaughtered me, and I would have ended up having to do something like Dentistry or Medicine.

Give Us This Day Our Daily Staple

Lately I've taken to buying bread on a daily basis.  I get a half bâtard from Coles Supermarket and while doing so I imagine I am in France. One of my great-grandfathers was French, so I don't feel as if I am kidding myself.  Two slices of bâtard with a sliver or two of cheese, and slice of onion, really makes everything worthwhile.

I was reminded of our daily staple yesterday, when I had a Rexel jam.  The staples wouldn't come out cleanly. They either jammed in the exit slot of the stapler, or bent in the paper, or had one of their legs break off mid-punch.

I have the solution to that problem - but I am always reluctant to use it.  I have a small supply of coppered staples size "No 16 24/6".  I know they will work. I do have a box of 5,000 steel size "No 16 24/6" but they are inferior in the bending department, and lead to the kind of problem I had. 

The trouble is I only have about 500 coppered ones left from a box of 1000 I bought 20 years ago, when Hugh, who turned 21 last Monday, 10 October, was just over one year of age.

We were living in Noosaville in Queensland at the time, and my parents had come down from Maryborough for a visit.  I must have been having similar staple problems then, for I went on a mission to find coppered staples.  My mother came with me. She showed enormous patience as I went from one stationery shop to another, being given strange looks by the shop assistants who were baffled by my request.

Coppered staples are not to be found just anywhere, and at the time I could only buy a small supply, and that was at a premium price. Since then I've had to ration my coppered friends for the times when I run into an inferior batch of steel ones.

No doubt, if I run out of my existing supply, I will pay an even greater premium for a new batch than I did 20 years ago. But these are inflationary times, and the price of bâtards has gone up as well.

Dog Whistle Politics

I don't think I really understand the meaning of Dog Whistle Politics, even though it is an Australian expression. However, I do have my own meaning for it. On the left is a photo of the park which lies over my back fence.  Of course it is dry and not very green compared to other parts of the world - but "red sand, green gum trees and blue skies" is my preferred view of the world.  In the foreground of the photo is a path which is a regular route which dogs and their owners take for exercise.  I managed to capture an Early Morning Walker and his two dogs on that path.  The photo quality is not all that I would like but I've put it on the right.  The connection between that path and my version of dog whistle politics will become apparent later on.

About two years ago my neighbour on the northern side told me that both of her dogs had died within weeks of each other.  I had not noticed their passing as they rarely made a noise.  She was obviously distressed but told me that she would soon acquire another pair of dogs from the pound and that, being younger, they would be "more outside" dogs.  I heard that omniously but made no comment.

About mid-2010 the new dogs were bothering me with early morning barking.  They were bothering me so much that I phoned my neighbour and said that I was being woken at dawn each morning, and often through the night by her new dogs. I mentioned that collars were available - either the ultrasonic variety, or ones that puffed out citronella - which discouraged dogs barking.  She said whe would look into it.

Little changed.

Just prior to Christmas 2010 my neighbour went away and left her dogs in the backyard to be fed and watered by a friend who would drop in.  Both dogs howled at the moon for two nights running. At my wits end, I phoned the Town Council Rangers who asked the friend to remove the dogs to another property until their owner returned.

I'll have to admit I made a diplomatic and political mistake when my neighbour returned and came to my front door, all apologetic and bottle of wine in hand.  I was in no mood to be placated and suggested that a laryngectomy would be a good idea for both dogs.  We haven't spoken since.

And the dogs continued to bark.  One problem is that the eastside fence which my neighbour has is not solid but is made of vertical metal bars spaced about 10 centimetres apart.  Her dogs can see through it to the park.  If children are playing or dogs are being walked the dogs next door decide that it is time to let the people in the park know who is boss.  I am often woken by the sounds of a dog fight early in the morning as the good burghers of Alice Springs continue to walk their dogs right where they know there will be a dog yelling match.

I contacted the Rangers several times; but the Rangers came and the Rangers went.  They visited me and snooped around. "Nothing we can do mate, we can't validate a problem." This despite my recording 15 minutes of dog barking in one half hour period, and delivering that to them on a CD.

In frustration,  I adopeted my own form of Dog Whistle Politics.  My dog whistle is a small Piezo speaker which emits an ear splitting sound. Dogs certainly don't like it even though it does not operate in the ultrasonic range which causes them pain. It hangs under cover near the north east corner of my backyard - near where the dog fights happen.  On the left is a photo of some gear I have rigged up to to fight my Dog Whistle battle.  My main aim is to get the humans to change, so that they might get their dogs to change.

While the electronic gear on the left might look a bit scrappy, to me it is a work of art!  On the left is a simple power supply. It brings electricity from the wall and puts out 12 volts DC into the circuit board in the middle of the picture. It also supplies current to the Piezo screamer via a long run of bell-wire from the lounge room to the backyard.  Just to the right of the red and black alligator clips in the middle of the photo is a small electret microphone.  When everything is turned on and powered up - just talking softly into that microphone makes the Screamer go off in the back yard.  The electronic circuitry is called a VOX switch - or voice activated switch.  When a noise is heard in the microphone the white relay box at the back of the circuit board connects the Screamer to the 12 volt supply.  The Screamer then does its thing for a seconds before turning off. However continuous noise into the microphone keeps the Screamer going.

Just to the right of the microphone is a walkie-talkie radio.  I have two of those. The second one is presently on my bedside table, waiting.  In the morning, when I hear the first dog bark of the day, I get up, if I am not already up, and turn on the VOX switch and the walkie-talkie.  I then go back to bed. And I wait.

Simply pressing the Talk button of the walkie-talkie beside my bed makes the walkie-talkie in the lounge room make a noise and the Screamer goes off.  I can repeat that trick as often as I like; but I try to do it only when I hear a bark.

My hope is that the early morning dog walkers will decide it is not worth coming near my back fence and take a different route in future. My other hope is that my neighbour will realize what is happening and do something about her dogs. I secretly hope that she thinks the whole setup is automatic and designed to go off whenever her dogs bark! I'm working on a version of that.

Believe it or not, I think my Dog Whistle Politics are working. I haven't heard a dog fight at my back fence for some weeks and my neighbours dogs rarely bark now during the day.  That might be because whenever they do bark I whisper into the microphone and they get a high pitiched whistle in return.

Resurrection

This is a photo of what I think is the first instar of one of the insects which are true bugs. Apparently, true bugs have a proboscis which is is perfectly designed to suck the juices from plants. This bug is commonly known as a Gum-leaf-tip Bug. The photo was taken sometime in early 2010 when I began growing a small herb garden.  I found these small insects cute until I realized that they, among other insects, were destroying my new crop of sage - which this one is feasting on. 

But that is not what I am here to talk about.  Today I decided to resurrect my blog "Tjilpi".

Recently I have spent an enormous amout of time at the Command and Control Centre [photo on right] writing and answering emails.  I thought it might be easier to publish a 'newspaper' and direct people to it, so as to allow them to keep up with happenings in the Old Eastside of Alice Springs. Of course I am more than happy to continue with email comings and goings, as it is unlikely that I will put much personal detail on these pages!  The photo is of my Laptop with a full sized keyboard in front of it.  That keyboard conveniently jumps up onto the keyboard of the Laptop when I begin to use my soldering iron, which is the blue box in front of the mouse. The folded bath mat under the large keyboard is a traditional surface on which to work when tinkering with electronics. Farther right is my trusty old Kenwood TS140S HF Transceiver, which is my 'Ham' Radio.  It's lights were not active when I took the photo so it looks like a dull grey rectangular box - but I have had lots of fun with it recently talking to people in faraway places such as Slovakia, Finland, Sweden, Japan, Christmas Island and East Timor.

Since I last signed up with TypePad - the people who host this blog - things have changed a little, so please forgive me for editing errors at the beginning. You can blame me for mistakes later after I get used to the new system.  Now that I am back, I hope to be able to produce many enjoyable posts - for you and for me. 

I know. I know what you are saying. "He'll spend even more time there now - writing blog posts, emails, and talking to faraway places.  Somebody should grab him by the scruff of the neck and make him go for a walk!"