The
picture in your briefcase; when time stood still
(From The
Sinclair Story, by Rodney Dale)
From time to time in this
narrative, like a faun a-peeping through the
green, we have espied Sinclair's elusive shade,
the miniature television. It is no surprise that,
with his passion for the miniature, Sinclair
should have turned his attention to television;
what is surprising is that success eluded him for
so long.
When he was working on
Instrument Practice, finding out all he could
about semiconductor devices, one of his topics of
conversation was the possibility of building a
miniature television set. One of my first jobs
when I joined Cambridge Consultants full time at
the end of 1963 was to search, on Clive's behalf,
for a supplier of miniature television tubes with
a screen 4cm x 3cm. I did obtain some sample
glass 'envelopes' from Tony Krause of Twentieth
Century Electronics, but as far as I know they
were never equipped with any innards.
Whatever difficulties there
were in producing an elegant circuit design were
overshadowed by the difficulties of finding a
miniature tube, and even miniature tubes still
needed enormous power to run them compared with
that needed by the rest of the set. Twenty years
ago there was no low-power CMOS circuitry, and
for continuous viewing batteries would have been
needed which were larger than the machine itself.
Typically, Sinclair's inventiveness lay far ahead
of what was practicable. Not that this stopped
him from pursuing the project; one of the first
TVs they made used a sawn off bit of a Sony
5" tube with a home-made bit bolted on to it
to produce a 2" diagonal picture. Sinclair
went off to see what was happening in the Far
East and returned to his designers with all sorts
of interesting components and a number of the
crucial cathode ray tubes from Hitachi. Jim
Westwood, who had been concerned with the
development right from the start, set to work,
and by 1966 the team was ready to show a
prototype Microvision, as the product was
inevitably called. Sinclair Radionics booked a
stand at the Radio and Television Show at Olympia
and as the great day loomed nearer the team
worked more and more frantically, later and later
into the night, to have a couple of sets ready.
Less than a week before the
show was due to open - on the following Monday -
some vital components still hadn't arrived.
There's nothing you can do about exhibitions;
like any other entertainment the show must go on,
and many an exhibitor knows only too well the
frantic preparation culminating in round-the
clock working and the final coat of paint even as
the Minister of Technology is saying what a jolly
good effort it all is, and cutting the ribbon.
This exhibition was no
different; the vital components finally turned up
on the Friday, and Jim Westwood went to work
immediately. He worked throughout the weekend,
hardly stopping to eat or sleep. But it was the
first time that the various parts of the circuit
had been put together and naturally there were
some unpredictable incompatibilities to be ironed
out before the sets would work. Sunday afternoon:
still no pictures.
It was decided that Richard
Torrens should set off for London on his own with
the other products Sinclair Radionics was going
to exhibit. Jim Westwood carried on working. At 3
o'clock on Monday morning he was ready to leave
the lab; he called the taxi that was on standby
and set off for Olympia. He had one Microvision
working and another needing only slight
adjustment.
The prototype Microvision was a
2" 405-line receiver which would handle all
13 channels in bands I to III. The speaker was a
2" piezoelectric transducer with an overall
depth of less than 1/4". The set was powered
by six pen light cells, and its total power
consumption was less than 450mW, including less
than 100mW for the tube heater. Its weight,
including the battery, was 10V2 oz. The
cathode-ray tube was designed by Twentieth
Century Electronics; using magnetic deflection,
it was just over three inches long, and there
were some problems both in handling it and in
assembling the set so that the spot would remain
adequately focused. Rather than using an
integrated circuit, which would have been ruled
out by the additional heavy investment needed -
for had not Sinclair already invested heavily in
the tube? - the Microvision contained 30
transistors and other discrete devices assembled
together in a three-dimensional package. The
packing density was incredible: components stood
on end where there happened to be convenient
holes, otherwise they lay down. Its design made
the Microvision very difficult to test, service
and repair.
And it had an interesting
side-effect. Chris Curry saw an example of this
marvel of compactness sitting on the bench, and,
with natural curiosity, picked it up. OUCH! The
set was switched off, but its EHT capacitors were
charged up to 2,000 volts. Fearful of the
consequences of dropping it, he tossed it into
the air and caught it. OUCH! The process
continued until all the capacitors were empty.
Despite its obvious
shortcomings, the Microvision was the star of the
1966 Radio Show. Three girls, dressed all in
silver - Clive's sister Fiona, his sister-in-law
Carol, and Sally Willey - ensured that no one
missed the Microvision, and would have distracted
the attention of the visitors if the sets had
packed up. They didn't pack up. A few orders were
placed by the intrepid in the expectation that
the set would be on the market the following
year, priced at £57.45, But it was never really
ready to be launched; the few orders were never
fulfilled.
This was partly because of the
difficulties in manufacturing the tube and partly
because of a fundamental design change: silicon
transistors had just become available and were
obviously going to be cheaper and more stable
than the germanium transistors used in the
Microvision. It seemed eminently more sensible to
carry out further development before going to the
market-place again.
Throughout the early and middle
seventies there were reports in the press that
the design of the Sinclair television was nearly
complete - and usually about a year from
production. Rumours were rife; the TV became
smaller and smaller, and one report even
suggested that Sinclair was really working on an
eye-level television that could be worn like a
pair of spectacles!
The two overwhelming problems
in developing a small television are the
circuitry and the tube, which doesn't leave very
much to achieve without effort. In 1973 Mike Pye
left Texas Instruments - where he had been
working on integrated circuits to join Sinclair
Radionics. He was to be research and development
controller for new projects; new projects
included a 2-inch screen portable television.
Technology transfer: Pye knew about the right
kind of integrated circuits so it was now a
matter of finding the right kind of tube. He
rediscovered Tony Krause, who was by then Chief
Engineer at Twentieth Century Electronics, and
who had been developing a tube for a flat screen
television.
Sinclair was impressed with
Krause's work, and it wasn't long before he left
Twentieth Century and joined Sinclair Radionics
as a consultant. Tony Wood Rogers joined at about
the same time, also to help develop the
cathode-ray tube.
The first outcome of this
collaboration was the 'coffin' tube, which was
about 6 inches long and presented a picture about
the same size as a 35mm slide. The glass envelope
was formed from three pieces: the front cap, the
top, and the bottom: in shape, it resembled a
coffin.
It was a low-power
electrostatic tube with the electrodes mounted on
long wires held in place by a frame while the
three glass mouldings were fused around them.
Positioning the electrodes accurately needed the
skill of the watchmaker. And when the tube had
finally been assembled and pumped out, the
components were mechanically very resonant; as
you might imagine, if you tapped the tube the
spot would swing all over the place.
Eventually Clive was forced to
call it a day on the coffin tube. It was a fine
design, but far too difficult to manufacture. In
fact, apart from the prototypes, none was ever
produced. However, as Sinclair has remarked: 'I
have an appalling habit of believing I'm right,
and once I decide where I'm going I'll get there,
come what may, however much I'm drawn off course
by circumstances.'
Where next to look for a tube?
Sinclair found that ITT had been working on a TV
project in the late 1960s, for which AEG
Telefunken had been experimenting with low power
consumption tubes. They had a number of
interesting designs, and after some discussion
agreed to help to develop a tube exclusively for
Sinclair Radionics. Their investment in the
development was eventually about £200,000, not
to mention the £25,000 they paid Sinclair to
help fund their part of the development. The
outcome of this work was that the TVIA - the new
Microvision - was launched in 1976, ten years
after the original model had been shown at the
1966 Radio Show.
The TVIA was aimed at the
international business market, mostly because of
the price - £250 while the up-market version,
complete with power supply in a lined case was
£650 from Harrods and Fortnum & Mason. The
set was 4" wide, 6" deep, and 1.5"
high. It operated either from rechargeable
batteries or from the mains. The black-and-white
picture could be viewed comfortably from about a
foot away. It functioned on VHF and UHF bands and
was the first-ever multi-standard receiver, which
meant that it could be used in nearly every
foreign country as long as the country used one
of the three major TV standards. It weighed some
26 ounces.
The key component was the
2-inch tube manufactured by AEG Telefunken. The
body of the tube was pressed glass made of two
halves split longitudinally. There was no
internal graphite coating; instead a metal shield
was used to collect the beam current the swinked
electrons which in their prime had caused the
screen to fluoresce.
The bulk of the electrical
circuit was contained in five bipolar ICs, three
of which were custom-designed for Sinclair
Radionics. The TVlA was significant not only
because of its size but also because Sinclair was
no longer taking available component hardware and
adapting it; he was now taking tricky design
problems by the horns. The TV1A's integrated
circuits, tuners and tube were nearly all
designed from scratch. It augured well for
British electronics.
By this time Sinclair Radionics
had a large export market, primarily because of
the calculators, so it was not long before the
TV1A was being offered in Germany and the States.
In fact Jim Westwood had taken an American
version of the 1966 Microvision to the States in
l968, but it hadn't worked very well and the
Americans had not been particularly impressed.
However, there was no reason why the Americans
should have remembered that Microvision, and once
the TVlA had been launched in the UK, it was
decided to display it at an exhibition in Chicago
in January 1977. This event is photographically
lined on the tablets of Jim's mind because no one
in the company had appropriate export experience
at this stage, and it was not until 15 December
that he was told what to go on show in the US the
TV would have to undergo tests for approval by
the Federal Communications Commission and the
Department of Health, Education and Welfare in
the US to ensure that no one would be X-rayed or
suffer from electrical interference. Clearance
normally took between three and six months!
Luckily, the Electrical Research Association at
Leatherhead agreed to test the Microvision just
before Christmas, and Jim Westwood recalls
stumbling around in heavy snow and failing light
at an RAF test range; as [he day merged into
night, the tests were carried out with the help
of car headlights and torches. But it was all
worth while; approval was granted just in time
for the exhibition.
The TVlA went on sale in the
United States for $400. Although orders began to
come in, it was fairly obvious that to sell
enough sets to cover development costs Sinclair
would have to lower the price. As one magazine
pointed out 'At nearly £10 an ounce it would be
a third of the price in solid sterling silver'!
This time, the Americans were
impressed. In GADGET, the newsletter for grown-up
kids, 'A.G.' reported on the Microvision he had
bought from Abercrombie & Fitch, New York
City, for $400.
'I felt like a kid awaiting
Christmas morning. Finally it came: the most
exciting and ballyhooed new toy of 1977, the
Sinclair pocket TV set. I rushed out to buy
it the minute it became available in New
York, even though $432 (including sales tax)
is a hefty price for a black and white
television,
'The set is as
revolutionary as all the advanced blurb
indicated. But before the praise, let's first
get its defects out of the way. My original
unit broke after three days, when the tuning
control jammed. Thankfully, Abercrombie &
Fitch has one of the best return policies in
Manhattan so the store gave me a brand new
set on the spot rather than giving me the
discount store runaround by forcing me to
wait for repairs.
'My replacement set is not
without other flaws. For instance, in a car
the picture is far from stable; it tends to
roll around. (New York City's skyscrapers
contribute to this, no doubt.) Also, the set
has a 15-second warm-up period. Another
irritation is that the tuning device is
incredibly slow-moving. One final gripe: when
the set is plugged in for recharging, there
is no visible glow light to verify that
recharging is taking place. But despite these
nitpickings, any GADGET reader who doesn't
buy a Sinclair Microvision simply cannot
afford to.'
But A.G. - clearly an
indefatigable gadgeteer - then sets out to extol
the virtues of his set:
'Another great capability
is that this is the only set that can receive
throughout the world, wherever there is a
television signal. According to the company,
it is the only such multistandard set
available today.
'The best thing about the
Sinclair Microvision for GADGET readers is
that, in spite of its smallness, it's
conspicuous. Wherever you are - buying a
beer, having a cup of coffee, or simply
sitting on a park bench - people will come
over and ask questions about the set. It's
like being the first kid on the block with
the Captain Midnight Decoding Ring - you're
the center of attention. After all, isn't
that why you're a Gadgeteer?
'On the more practical
level, the Sinclair does plug you in to the
world of not-to-be-missed TV shows. Sure,
some of you GADGET readers have video
equipment that can tape a show you would
otherwise miss, but with the Microvision you
can watch it as it's broadcast wherever you
are. Ironically, I got my Sinclair one day
after the New York City blackout in July. If
I had had it earlier, I could have watched
the goings on in the city while the
electricity was out, since NBC and CBS
continued broadcasting on emergency
generators.'
And A.G.'s conclusion?
'Clive Sinclair, president
of the company that makes the Microvision can
be proud of his accomplishment. Although we
cannot give this set unqualified praise, we
still think it is an exciting contribution to
our lifestyle, and we recommend it to GADGET
readers. If you purchase your set from a
top-notch store with a good record of
replacing defective items, you will be
thrilled to own this electronic miniature.
'Hopefully, within the next
two or three years, Sinclair will bring us a
pocket set that will enhance viewer pleasure
even more by including a color picture tube.'
Unfortunately, the price was
governed by the cost of the special circuitry
that enabled the set to work on several different
transmission standards and consume less power, so
there was no way of lowering the price on that
particular model. There were also the inevitable
production difficulties, although the sets that
were sold generally worked perfectly. Sinclair
had already learned the importance of quality
control; a sample from each batch of televisions
underwent rigorous tests before the batch was
released.
There was soon an adaptation of
the TV1A on the market: the monitor Mon1A. The
principal user was a company called Bywood who
used it as a tiny monitor with a display of 10
lines with 15 characters. It had an extremely
rugged case, as used in police walkie/talkies.
Sales of the Mon1A were small but consistent, and
continued for a number of years.
Sinclair was determined to make
the TV1A as small as possible because: 'This is a
pocket portable; ifyou can't get it in your
pocket it's not a pocket portable'; once again,
the components were tightly squeezed into the
space available, and this made it difficult to
manufacture. There was a very small clearance
between the PCBs - which sometimes carried quite
a high voltage (up to 2kV EHT) - and the case. It
was therefore necessary to put an insulating
layer inside the case, but when it came to
assembling sets there were problems in getting
the case sleeve over the innards and, if the
insulation ruptured, short circuits were
inevitable. It was really only a matter of a
fraction of an inch, but by the time anyone
realised the difficulties it was too late.
However, the company managed to
bring the output of the TV1A to about 4000 a
month by the Christmas of 1977. There was now a
labour force of 150 in the factory at St Ives,
half working on TV1A; 75% of the output was
exported, chiefly to the United States.
Meanwhile, development was
pressing on with the next model, the TV1B. John
Lawton, who designed its sound system, remembers:
'It was hell in the production department, I kept
my nose out of there, there was too much going
on. They had a flow-soldering machine which
cooked the boards being used for the TV1A. These
were very thin SRBP boards and someone would turn
the temperature up too high occasionally, which
warped the oards and made inserting them into the
case even more difficult.'
The TV1B was known as the
'plastic box TV'. It was designed for automatic
production and very low production costs. In the
TV1A all the components were inserted manually
into the five PCBs, using overhead projectors. In
the TV1B the main circuit fitted on to a single
PCB which was double-sided and through-hole
plated. This more expensive technology, which was
new for Sinclair, allowed a much higher component
density and automatic production. The other PCB
was a new high-tech UHF stripline tuner. The
prototypes were built in Radio Spares plastic
boxes.
The first version was for the
UK only because a VHF tuner, which was not
available at the time, was not needed. It used
the same video ICs as the TV1A but the sound
system was reduced from two ICs to one. The
speaker was made in Taiwan and was much smaller,
and there was a new AEG high brightness tube. It
had an automatic brightness control but produced
an inferior picture because there was no black
level clamping. The power consumption had been
reduced so that the set would work on four
calculator batteries (HP11s) which could be
replaced or recharged. It would run for about
eight hours per set of batteries, which meant
that it cost 12p an hour to run.
The TV1A had had a metal sleeve
case with plastic ends and this had caused some
of the shorting problems; the TV1B slipped into a
plastic box which, once tooling costs had been
met, would be much cheaper to produce and could
never cause short circuits.
Both the TVTA and the TV1B used
most of their power consumption for sound; the
TV1A used about 100mW without sound which isn't
all that much, though it could be used quite
effectively as a torch. Although the TV1B had a
one-inch speaker, it still used a lot of battery
power for the sound; both sets were better if
they were used with earphones.
The TV1B was finally launched
in the autumn of 1978 at the Roof Garden of the
Hilton in London. For the American market a VHF
tuner was necessary; the one on the TV1A was
insensitive so a new one was developed. This
model went through its FCC tests and was called
the TV1C. It went on sale in the US but not for
long; for the TV to be a success a mass market
was essential and this meant more than the UK or
even the US, but Europe as well. In Europe there
was a different sound frequency so the design of
the TV1D was put in hand. Unfortunately, for
reasons which we will come to later, the
marketing effort was never sufficiently
wholehearted for development costs to be
recovered. Sinclair Radionics particularly needed
the TV to be a success, because it was seen as
the one product which had the potential to
generate cash, for which Sinclair was now
becoming increasingly desperate.
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