Tag Archives: technology

Tune in to early TV transmission in Queensland

by Peter Volk, Assistant Collection Manager, Social History, Queensland Museum

On 1st July 1959, nearly 60 years ago, Brisbane television station QTQ9 went on the air. A few months later, on 2nd November, ABQ2 started broadcasting as well. If you are of the right age, you can remember growing up on a steady diet of 1960’s era TV, all served in black and white, with monophonic sound, all delivered on a 576 line screen.

However, QTQ9 wasn’t the first TV station in Queensland, not by a long way. TV transmission in Queensland started on 10th April 1934, and the first TV broadcast license was issued to radio station 4CM in 1935.

What did TV look like in those days, and why did it take 25 years (!) before it became generally available?

H44978.6 & 7 b
Nipkow DIsk and Photocell used for the first successful transmission of a television signal in Queensland on 10 April 1934. This was the heart of the TV system. The rapidly spinning disk with pinholes in the rim scanned the subject with a moving dot of light, and the “TV Eye” acted as the camera. It was a simple photocell that measured the light intensity and output a proportional electrical signal. Notice the use of cotton reels and Meccano in the construction of the supports and frame.

Experimental radio station 4CM broadcast from the convict-built Old Windmill on Wickham Terrace in Brisbane. The initial TV experiments were made late in the evening after the radio station had gone off the air. Dr Val McDowall, who owned the radio station, worked with Thomas Elliott, a local engineer and one of Queensland’s first licensed HAM radio operators, to build a TV transmitter. There were no standard components for such a thing at the time. This technology was beyond the cutting edge, so they had to improvise. The transmitter included wooden cotton reels, parts from a Meccano set and hand-cut aluminium disks. They worked with another gentleman named Alan Campbell, who went on to be a co-founder of QTQ-9. Mr Campbell had a TV receiver that was an equally home-made affair, with a screen 11 cm wide, about the size of a mobile phone screen today. Together these three men made history.

The first successful transmission of a television signal in Queensland was made on 10 April 1934, and was picked up in Mr Campbell’s home at Wilston.  The first image seen was that of Mickey Mouse, followed by a picture of actress Janet Gaynor. The first news transmission took place on 9 October 1935 with a reading from a section of a local newspaper. The first entertainment included cartoons of Mickey Mouse, and a film called “The Chocolate Soldier,” using a projector Mr Campbell had built.

The TV signal could be charitably described as low resolution. The more scan lines a TV has the better the picture is. A modern hi-definition TV has a minimum of 720 scan lines, and more commonly 1096. 4000 line (4K) TV’s are available now, and 8000 line sets (8K) are entering the market. The old B&W TVs had 576 lines. The early TV signal from 4CM’s apparatus had 30, though a later version of the equipment used a 180 line scan.

The early 30 line transmissions used a rather long radio wavelength, which gave them a good range. It was reported that 4CM had been picked up by receivers in Melbourne. Soon after, along with the shift to 180 line scans, the transmission frequency was raised. The resolution of the image was now much better, but the range was reduced to about 25 miles.

H44978.6 & 7 dThe receivers were about the size of a regular computer monitor, but most of that size went to housing the mechanical works. The actual image size was very small by comparison – from the size of a large postage stamp to the size of a mobile phone screen.

Nipkow DIsk and Photocell used for the first successful transmission of a television signal in Queensland on 10 April 1934. This was the heart of the TV system. The rapidly spinning disk with pinholes in the rim scanned the subject with a moving dot of light, and the “TV Eye” acted as the camera. It was a simple photocell that measured the light intensity and output a proportional electrical signal. Notice the use of cotton reels and Meccano in the construction of the supports and frame

This was a mechanical TV system, of the type championed and improved by John Logie Baird in the UK. The core of the TV was a spinning disk, called a Nipkow disk, with a series of holes in the rim of the disk forming a spiral. The subject was seated in near darkness, and a very bright light (usually an arc lamp) projected a pinhole sized spot of light through the holes in the rim of the Nipkow disk. The disk was spun very rapidly by an electric motor. The spacing of the holes meant that only one pinhole passed in front of the subject at a time, and the spiral pattern of the holes meant that each hole passed over a different part of the subject, moving from left to right until the whole subject had been scanned once. The wheel had then done one rotation, and on the next the subject was scanned again.

This scanning process became known as the “flying spot” technique. It was used in early broadcast TV up until 1938, in some places, and is occasionally used for specialist applications today.

Close-up view of the scanning disk. Everything was hand-built from what was available.

A photocell measured the intensity of the light reflected from the subject, and sent a signal to a second light source (usually a neon lamp) that varied in intensity according to the signal. When one looked at the second light source through a similar Nipkow disk spinning in synchronisation with the first, one saw a copy of the original signal. The trick was sending that light intensity signal to the second light source over a radio. If one can do that, one is transmitting TV. Audio was transmitted as a radio signal over a different frequency.

H44978.6 a

It seemed that the Brisbane experimenters had the core of a successful television system. They commenced regular TV transmissions, for an hour every evening from 7:30 PM. Initially everyone had to build their own receiver from scratch, but with a bit of time and capital receivers could have been manufactured and sold to the general public. Commercial broadcasting and professionally made receivers were both available in the UK from 1929. However, the steady development and deployment of the technology was stopped dead by World War 2.

When war broke out in 1939 Australia, like the UK, withdrew all the broadcasting licenses for experimental radio and TV groups and put all their scientific efforts into military projects. The people who had been working on TV transmission had made themselves the best in Australia at cutting edge radio technology. Instead of broadcasting Mickey Mouse cartoons they found themselves working on radio and radar projects for the military. TV research went into suspension around the world – except for experiments with TV guided bombs. After the war the 4CM TV crew found that their lives had taken different directions, and the band never got back together. Additionally, mechanical TV had fallen by the wayside and been replaced by TV that used an electrically scanning cathode ray tube for the transmitter and receiver. This led to one of the first format wars, where various nations could not agree on the number of scan lines, the number of frames per second and other technical details. Australia as a whole was uncertain as to which technology to adopt. There was also dispute about how the TV industry should be organised. The British model had the government, through the BBC, running the TV stations and the U.S. model had the stations owned and run by private industry.  After much argument in Parliament the Federal Government made the firm, principled and determined choice to have five bob each way and do both. Additionally, in the early 1950’s Australia was in a recession and the capital and skills needed to develop a new industry weren’t available until later in the decade.

This early TV transmission equipment found its way to the Royal Historical Society of Queensland, and from them to the Queensland Museum, where it is preserved today. As far as is known, none of the early TV receivers have been preserved anywhere in Queensland.

Reconstructing the Kronosaurus

Kronosaurus queenslandicus was the largest predatory reptile to swim the seas of western Queensland 105 million years ago. This icon of the paleontological world is thought to have grown up to 11 metres in length, with around two metres of that dedicated to its unusually large skull, containing a mammoth set of jaws and dozens of enormous teeth.

Recently, an opportunity arose for the Queensland Museum to add to the State Collection with the acquisition of two lower jaw pieces from a large individual Kronosaurus. Although the Kronosaurus is an iconic animal, surprisingly little is known about its biology, with skulls and jaws a relatively rare find.

Kronosaurus queenslandicus was named in 1924 by Queensland Museum palaeontologist and former museum Director, Heber Longman, based on a piece of jawbone that was discovered near Hughenden, in central Queensland. It was named after the Greek Titan Kronos; so horrible that he ate his own children. Kronosaurus is a pliosaur, an extinct short-necked marine reptile. Its powerful jaws – which worked in a similar way to a crocodile’s – contain rows of large conical teeth, the biggest of which are nearly 30 centimetres long. Kronosaurus was a fierce predator – remains of its stomach contents found in central western Queensland indicate that it fed on turtles and other long-necked marine reptiles. Kronosaurus fossils have been found in the sediments deposited by the inland seas and turned to rock, ranging in age from 112-100 Million years, during the Early Cretaceous Period.

MOTQ-BrochurePhotoshoot-HighRes-114.jpg

This particular specimen was found by a private collector near Boulia in western Queensland and, through negotiations with Dr Andrew Rozefelds, Head of Geosciences, Queensland Museum, was acquired through generous Queensland Museum Foundation donations directed towards object acquisition. The jaw adds to the Queensland Museum’s collection of Kronosaurus specimens. The acquisition of the specimen will ensure that this important piece of Queensland’s geoheritage is preserved in the State Collection for perpetuity. Importantly, it will also provide an opportunity for both researchers and the broader community to get up close to this fascinating specimen.

But as is the case with most specimens of this nature, the jaw was not in perfect condition, which meant that certain work needed to be done before the object could be properly studied, displayed and stored safely within the collection. The main goal for the Geosciences team was to cradle the pieces of fossil as best possible, whilst demonstrating the aspects of the jaw that were missing, especially its teeth. Senior Technical Officer, Ms Debra Lewis took on this meticulous and detailed work.

To present the jaw in a life-like pose whilst also safeguarding it from damage, Debra began work on a bespoke base that would serve the dual purpose of supporting the specimen whilst allowing it to be displayed. Debra said that creating such a base is a lengthy process due to how customised it needs to be.

de4361.jpg

“The base is made of timber but each one contains an individual cradle sculpted from polymer plaster to suit the weight, angle and intricacies of each piece of jaw. The cradle was glued to the timber and filled in with expandable polyurethane foam, which was then sanded off to create the shape of the base’s sides. Over that, two layers of fibreglass were carefully applied to give the structure strength. The final step was a coat of paint in a specially chosen shade that would not detract from the ‘hero’, our Kronosaurus jaw.”

As the teeth and part of the bone were missing, careful work was done to demonstrate this as accurately as possible. The teeth were made using 3-D modelling and printing – technology that Dr Scott Hocknull, Senior Curator, Geosciences, has developed within Queensland Museum and has become a key feature of his research and engagement work.

“In this case, the benefits of this technology served as a huge time saver,” said Scott.

The usual method for producing replicas is creating a plasticine sculpture and using that to make a mould and then cast from it. In this case, the process would need to be repeated for each individual tooth – all 16 of them – which Debra and Scott estimate could have taken a month of work or more. The same result using 3-D modelling and printing took about 36 hours, with most of this made up of printing time rather than manual labour. This is achieved through digitally modelling one tooth, then digitally sculpting a 3-D model of each of the 16 teeth. Using photographs of the original tooth, a 3-D model of it was created, which can then be modified and printed out. Debra then hand painted each tooth in a colour that matched the remaining bone. The final piece of the puzzle was to come up with a way that the teeth could be displayed so that it was obvious to viewers which part was original fossil and which was a reconstruction.

de4381.jpg

“Part of the bone was missing, so rather than replicating this on top of the original, we decided to use clear perspex rods to place the teeth at the correct height and show the position of the teeth as they would have been in the jaw,” said Debra.

This was done by gluing each newly made replica tooth to a clear rod and placing it into a small indentation drilled into the matrix (a build-up of rock where the tooth would have sat) so that the rod would fit snugly and can easily be removed and replaced. So where to from here for our “revamped” Kronosaurus jaw?

The Geosciences team hope that the specimen will go on display, possibly within the permanent Lost Creatures exhibition at Queensland Museum, where it can be enjoyed by visitors. It is currently available to researchers and is being studied by a PhD student, who has been 3-D scanning the pieces of the jaw to reconstruct the animal digitally and learn more about its palaeobiology. Of course, a scientist’s work is never truly done – there is always more to learn and new examples of these extinct species to be unearthed, which in turn will bring new opportunities for research and discovery.

“We’ve known about the enigmatic Kronosaurus for a long time – hopefully we can continue to find out more about this icon of the Cretaceous inland sea,” said Scott.

Behind the Scenes – Queensland’s First TV broadcast

When was the first TV image broadcast in Queensland?

If you thought 1956 or 1959, you’d be wrong.  The first TV broadcast was made in 1934 by Thomas Elliott, from the Windmill Tower on Wickham Terrace using the machine featured in this article. I discovered this fascinating piece of technology carefully stored and cared for by Museum curators, in the storage area of the Queensland Museum.

This is a component of home made equipment used to send the first television signals in Queensland, and possibly Australia (Image: Copyright Queensland Museum 2011)

Over a period of months, Thomas built a television transmitter reportedly using materials including cotton reels, aluminium discs and Meccano set parts. A receiving set owned by advertising man Alan Campbell (later co-founder of Channel 9 Queensland and patron of the South-East Queensland Amateur Television Group) included equally diverse materials, such as pieces of aluminium, copper and brass. It had a screen 11cm wide.

The first transmission was made on 10 April 1934 from the observatory to Campbell’s home at Wilston Heights. The first image seen was of actress Janet Gaynor. 4CM was given a television broadcasting license the same year, 1934 and continued to broadcast until all licenses were withdrawn following the outbreak of war in 1939. The group did not resume after the war, but Elliott declared that Australia could have introduced television in the 1930s but for the War.

This object provides a fascinating insight into how science and technology have changed over the last 100 years.  For more ideas and resources to teach science and technology in the classroom try investigating  QM Loans. Loans kits available to borrow include Telecommunications, Early Queensland Living and Australian Inventions.