Feedback: your letters

As we hand over to our readers we become aware of appalling discrimination lurking at home and the workplace. Robophobia!  It seems the soon to be man's best friend needs an image makeover.

Robophobia is alive and well

The article on older people's reluctance to use assistive technologies ('Home Help', Vol 4 #17) touched a nerve. Back in the 1970s OMNI magazine carried an interview with Dr Isaac Asimov. In it he mentioned that in the 1940s and 1950s, when domestic robots were a distinct possibility in the near future, he was amazed at ordinary people's hostility to the idea. Delving into the subject, he discovered that the reasoning behind this 'robophobia' was the current science-fiction genre depicting robots as either the eliminators or enslavers of mankind. (Usually with a scantily clad young female on the cover, screaming in the arms of some evil machine!)

From this, he formulated the Three Laws of Robotics, and went on to write the 'I, Robot' stories depicting robots as what they really are - basically a machine tool, or appliance. Like machine tools and appliances, the stories showed what could happen when robots went wrong.

The three laws were not perfect. If they were, the stories couldn't have been written. In each, however, the reasons behind the robots failure always came down to human error, either deliberately or by way of an accident. In other words making robots no more dangerous than, say, a chainsaw or a car. Subsequent stories reinforced this idea.

Fast forward to the present and we have 'BattleStar Galactica', a TV series about robots created by man, trying to wipe out mankind, and the Will Smith Hollywood blockbuster based on Asimov's stories, in which the central computer decides to take over the robot population and use it to bring the human population under control. In both cases, robots are depicted as cold violent killers, the exact opposite of that which Dr Asimov tried to depict.

So you see, it doesn't surprise me that assistive technology of any kind is treated with suspicion.

Reid Thomas IEng MIET, Cranleigh, Surrey

No regrets about choosing ATRAC

I am sorry to say that I agree with Bernard Smart's comments on how the spread of MP3 and other digital formats has reduced demand for high-quality audio.

The whole of my working life was spent in various aspects of audio from PA and consumer products to professional recording and broadcast applications. When I began work in the 1950s, the object of the exercise was to produce reproduced audio of the highest possible quality and as close to the original sound as possible. When I retired, particularly in the consumer field, the object was (and is) to produce maximum quantity in the smallest physical size of just about acceptable quality sound!

I had a very large number of high-quality LPs (many of them limited edition direct to disc products) which were taking up too much space and I had to copy them to a more compact format. I was able to borrow a good MP3 recorder/player and compare it with a Sony MiniDisc recorder.

Even to my aged ears the lower compression of the MiniDisc's ATRAC system produced a much higher quality sound then that provided by MP3. As I knew that the MiniDisc system was widely accepted in the broadcast field with its ease of editing, titling facility and good quality sound, I adopted that and have never regretted the decision. As far as my own acquisition of quality music recordings is concerned, rather than waste time downloading loss-free files, burning a CD and then preparing labels etc, I would rather simply purchase online when the whole product comes to me with full notes.

Sadly, the marketplace has decided that quantity and portability, with small headphones being the preferred listening environment, has meant that the iPod and its clones have taken over. What is equally inexplicable is that the compact cassette, with its wow and flutter and clumsy rewind time, soldiers on.

I shall carry on listening to my CDs and MiniDiscs on large infinite-baffle loudspeakers and wondering at the ways of the world!

Derek Roughton MIET, Ovingham, Northumberland,

Where is the will?

Well said, Alan Leary ('Selfish Profession?', Letters, Vol 4 #17). I am someone who has spent the best part of 40 years in electronics engineering and I am currently unemployed. Why? Because the company I worked for, a well respected small firm specialising in the early detection of fires, was bought by a foreign company, all the employees were made redundant and production moved to China.

How many jobs were created by this move? None. None in this country and none in China (the subcontractor had spare capacity). The purchasing company had been steadily shedding jobs and made the purchase knowing that a large order was in the pipeline; ie they hoped to make a quick killing out of the deal (well, that's business).

Who benefits? Nobody so far, as the large order has not yet materialised. Perhaps the change of ownership of the company has set back the order pending proof of capability by the new owners.

Of the dozen or so employees (I said it was a small company) who lost their jobs, four have found other work, none of them in engineering. As I am 62 years of age I would like, but do not expect, to be able to continue in my chosen profession. This government would also like people to continue to work past their retirement age. Surely the government are able to do something to promote jobs in this country, to minimise loss of talent and experience, if they have the will. On past experience, I shall not hold my breath. Companies cannot be expected to sponsor workers if the government will not help them.

Bob Shepherd, Worthing, West Sussex

Malaysian power

Regard Clive Read's letter on energy efficiency in Australia (Vol 4 #16), I have just taken early retirement and, with my wife, emigrated to Kota Kinabalu in Sabah, Malaysia. The electric company here also has a scaled-charge system, this being the first 40 units at RM0.24 (4.4p), next 160 at RM0.16 and the remaining units at RM0.28. I think this is a good way of encouraging users to restrict their usage. Also most of the light bulbs sold are the energy saving type.

The meter is read once a month and a bill is printed off and posted though our letter box by the meter reader which we then pay online.

Graham Boys, Sabah, Malaysia

ECT regulation

Ian Darney argues (Letters, Vol 4 #17) that the status of engineering as a profession is tarnished by the practice of electroconvulsive therapy (ECT). Manufacturers of ECT equipment, like those of all other medical devices, are already subject to the requirements of the Medical Devices Directive and FDA regulation.

In Europe, all medical devices legally must be certified in conformance with the Medical Devices Directive, and this demands that safety and management of risk to patients, medical staff and bystanders is integral to the product development process; and that the device has been proven to be safe and effective in its intended clinical application. This also (and for any other class II or III device) requires evidence that an independent Notified Body has audited the technical file and has approved the evidence provided for device safety and effectiveness.

If anything, the degree of regulation of medical devices is significantly greater than that applied to his example of mobile phones.

There are many examples of devices produced by engineers that, when used for the intended purpose, significantly enhance the well being of their user. In my own field of life-support equipment I design equipment that saves lives, but which used inappropriately could do significant harm. The same has to be said of almost every manufactured device in common use: cars sometimes crash, with lethal consequences; every year people die of electrocution caused by kitchen equipment; and even the humble tea-cosy is cited as cause of accident requiring hospital treatment by several dozen Britons each year.

Paul Dixon CEng MIET, London

Magnetic recording

In response to EurIng TRE Sizer's query (Vol 4 #17) about when tape recorders (as opposed to wire recorders) first became available in the UK, I think that the first was the Blattnerphone which was used by the BBC for speech recording from the early 1930s.

This used quarter-inch wide steel tape running at about 5ft per second and the huge and heavy reels gave 30 minutes of recording time. Subsequent models were improved over time until they were superseded before the war in Germany by the Magnetophon company using cellulose tape made by BASF. During the war, the Germans developed the use of high-frequency biassing which greatly improved the quality over the previously used dc biassing, and they had a reasonable quality stereo tape recorder by 1943. Both AC biassing and coated cellulose tape were originally patented around 1928.

I built my first tape recorder around the end of 1948 using one of the first Wright and Weaire tape decks, produced before their subsidiary company Ferrograph was set up to make complete machines. These Wearite tape decks used quarter-inch cellulose-backed tape, operated at 7½ and 3¾ ips and were initially sold to the then large amateur radio public for £25.

From memory, EMI started manufacturing studio tape machines (the BTR1) early in 1948, and these were soon replaced with the famous BTR2 used by many organisations including the BBC and the Post Office. I bought my first tapes from Simon Sound Services in Wigmore Street, who sold 11in reels of quarter-inch cellulose tape for use on the BTR machines, and rewound them on to 8mm 7in film spools which fitted the Wearite decks. Wearite's own spools were 8½ inch diameter and ran for 45 minutes at 7½ ips.

It was a tribute to the fine engineering quality of the early tape heads on the Wearite decks that I managed to attain a frequency response of 50Hz to 14KHz within ±3dB and a S/N ratio of 68dB when better tapes such as Durex (renamed Scotch Boy) and BASF became available in this country around 1950.

At that time several commercial recorders of significantly poorer quality became available and the fun of recording became more commonplace. These suffered from problems of audible wow and flutter and poor frequency response due to lack of precision engineering in order to cut costs. In addition, several inferior quality tapes were produced, even a paper-based one using a coating of Fe3O4 instead of the usual Fe2O3.

In my opinion, the Ferrograph remained the best of the small recorders until the 1970s when the company merged with North East Audio Ltd (NEAL), who continue with the manufacture of specialist recording and interview machines.

Anthony Harrison FIET, Leyburn, North Yorkshire

 

The early history of magnetic tape recorders, such as the Blattnerphone and the Marconi Stille machine is well covered at www.btinternet.com/~roger.beckwith/bh/menu.htm. These machines were developed in the 1930s. There was an example of the Marconi Stille machine at the Science Museum many years ago. The tape deck was about 1.5m high, 1.5m wide and about 1.0m deep. There were also 19in racks of electronics. The reel for the 3mm by 0.08mm tape was 600mm or so in diameter and weighed 25 pounds. It ran for 32 minutes.

I worked with a colleague who had used the Marconi Stille while at the BBC many years ago. He told me that the tape was joined for editing with a spot welder, and, as it was like a razor blade, there was a BBC Engineering Instruction that all off-cuts had to be no longer than 6in before being put in the waste bin. Health and Safety was alive and well even then.

Tony Meacock, Norwich, Norfolk

 

Wire recording was available to the general public before tape recording. The exact dates of their original successful operation I do not know, but I do know that in 1951/1952 I was experimenting at home with audio wire recording, using a capstan on a record player turntable at first. I did succeed in passable audio recording, but never really tied down the many variables. The wire was fairly readily available, but wire breakage and handling was a nightmare - I still have a reel of some km of the stainless wire somewhere in the back of a garage!

One domestic wire recorder which I remember seeing in the shops in 1952 was the KB (Kolster-Brandes) wire recorder, which if I remember correctly was housed in a rather large cabinet reminiscent of the old radiograms. Its price was beyond a student's means, and I doubt if many were sold.

Tape recording became available a very few years later. I do remember in 1957 a colleague bringing a recorder from his laboratory to record a wedding. It was a pretty well-developed reel-to reel machine using 1/4 inch tape, but very large and heavy. Therefore it seems reasonable to estimate that tape recorders began to be available somewhere around 1955-56. However, the tape was probably in use in laboratories or industry before then, as I remember seeing miles of discarded tape about 1 inch wide in a scrap bin about that time.

HC Burford MIET, Ryde, Isle of Wight

Missing horsepower

I read the article on the design for a new London Bus (Vol 4 #16) with interest. However, when I got to the characteristiscs of the old Routemasters I recalled the Flanders and Swann song which includes the line: "The big six-wheeler scarlet-painted London transport diesel-engined 97-horsepower omnibus".

Is there an explanation for the discrepancy between this and the 115 horsepower claimed in your article? It certainly would not scan so well!

Brian McGlinchy FIET, Wellington, New Zealand

Bright idea

The letter from John Harrison on recharging primary batteries, (Vol 4 #16 ), reminded me of my own experiments in the 1950s. I was apprenticed to a Nottingham firm of telecommunication engineers, and, as was customary in those days, cycling to work, to night school, and in my case, training for my chosen sport of cycle racing.

In winter, the cost of replacement batteries for the conventional twin-cell cycle lamp was, for an apprentice, considerable, and I employed a system of recharging using a half wave rectifier, with a small discharge current via a bleed resistor during the other half cycle. Although the recharged battery life was less than that of a new battery, I recall that the initial terminal voltage was slightly higher, and I was able to repeat the procedure for many cycles, degradation of the zinc casing probably being a limiting factor.

I believe my call-up for National Service terminated the procedure.

Ray Booty CEng MIET, Allestree, Derby

 

John Harrison (Vol 4 # 16) describes a couple of interesting ways of recharging "dry cells", without giving away too many secrets. Does no-one remember the "Dirty DC" method that was so popular many years ago? All you have to do is connect the dry cell to a low voltage AC supply via a single-phase rectifier across which you have connected a suitable resistor. Don't ask me what value resistor!

Stuart Bridgman CEng MIET, Wellington, New Zealand

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