MY YEAR
In 1928 I had just finished a year's research in
Lubricating Oil, and also had failed to get a job in that business. Somehow I
got to hear that the Daily Express needed somebody to look after the Picture
Transmission equipment,
which they were buying from the Americans, so I applied. This was
not really my line but I was lucky. The chief engineer of the Express knew even
less about the subject than I did. He
offered me £6 per week
( multiply by 50 to get present day values ), 6 weeks probation
on half pay, all subject to the approval of the Americans, who were to install
the equipment. As I and my widowed mother had been living on a war pension of
30 shillings a week, this was riches indeed.
The Daily Express at the time was owned by Lord
Beaverbrook. He was personally pushing it all along. The Paper had originated
in
He had been greatly impressed when visiting the states
by the Western Electric version of Picture Transmission equipment set up as a
public service between
When the big presses were operated at full speed, the
whole building rocked. The site had once been a marsh, either from the Fleet of
the
Meanwhile the rest of us got on with the Power Supply.
The big presses were supplied with 800 volts DC, and the lesser sized ones with
400 volts DC. This was not much use for us. Converters were fitted to produce
American style 115 volts DC, and a lower voltage for battery charging. The more
technical part of the installation ran on 24 volt accumulators, and 130 volt
ones for the HT supply. This was standard practice then. Studio Telephone
Exchanges and the like, were all on this sort of
supply. There were of course 2 sets of batteries, one in use and the other on
charge.
As the general tarting up of
the building was still going on, nobody except a few Top Brass
got a fixed office. I got shifted in to share with lesser beings a number of
times. Once I was put in with the famous 'Beachcomber' of that time. I don't
think he really liked me, he never replied to my morning greeting, and when I
was there he studiously read the newspaper. Another character was a hoot, he had new ideas on everything. I remember I was
harangued on the errors of
The one day the equipment was sighted in London Docks.
The Customs and Excise did their usual act. The promptly claimed that the
device was a camera and should be charged duty at some enormous rate. In the
end we paid duty on a few not very expensive lenses only. I was to see them
trying the same trick years later when the first Ampex
Video Recorder was imported by AR. That time the tried to prove the machine was
a Musical Instrument.
The gear was shipped from the docks to
installations. Some of the wire involved was really hefty, and would have been
impossible to get round a bend. After a lot of argument they withdrew their
ruling, when it was pointed out to them that almost every wire had its little
Grasshopper fuse; there were rows and rows of them.
However we had by no means heard the last of the
stranded wire story. The master plan called for the main earth to be solid ASWG
gauge 3 conductor, and an insulated one at that. This
took months to arrive and 36 ft of it duly appeared, and was connected firmly
to an incoming High Pressure Hydraulic Main, which supplied the lifts which
carried the big rolls of paper from one level to another.
When set out the equipment was found to be nicely made . As
received it was intended for the source to be a Transparency, this was made to
rotate and move along a lathe bed by the action of a lead screw with 100
threads to the inch, plus a rotating splined shaft
for the rotation. It could operate in either direction. A spot of light was
focused on to the film, and a photo-cell was placed inside the rotating film to
collect the signal. It was nothing special, but as its sensitivity was only 2 microvolts per lumen, it was an early potassium one. There
was plenty of light from the spot to provide a sensible signal. The cell
current passed to a DC amplifier made up of many Dry batteries and a few resistances,
which was an absolute so-and-so to set up. It was however stable enough when
finally adjusted. The signal still having the DC component
then passed to a modulator, where it took the audio carrier frequency.
The drive for the carriage was a two-phase 115 volt 60
Hz motor of low power produced by a 60 Hz tuning fork. The motor was a
fly-wheel of lightly made metal, and contained some 14 lbs of mercury. This
enabled a start to made with a dog-clutch, as the
light flywheel could quickly accelerate, and the liquid mercury could catch up
a few seconds later. The motors were not self-starting, but they could run in
either direction if brought up to speed with a modified hand-drill. They had I
think 20 pairs of poles and ran quite slowly. It was easy to run them up to
speed and they locked in readily.
The master tuning fork in
Once during my stay with the 'Express' there was great
excitement as the
The actual recording device which varied the amount of
light falling on the photographic paper, was a typical
Bell Labs 'Lightvalve'. This had a single dural ribbon flanked at each side by knife edges not quite
in the plane of the ribbon. The ribbon was in a very strong magnetic field, and
was tensioned to resonate at the carrier frequency. This might have expected to
have given a heavily peaked response, but the high magnetic field kept it down
to a few Dbs ( or TUs as they were then ). During a period of operation deep
red lighting was used. After some hours in this it seemed to have changed to a
rather nasty shade of pale pink.
The Post Office provided a four wire system of lightly
loaded cable for the system. It had hoped to get unloaded lines, but these we
could not have. The small loading coils gave as expected a low pass filter
effect which included a phase shift, which the long run to
There were I think at that time 14 repeater stations
between us and Glasgow. For the first weeks of transmission they spoilt nearly
half the pictures sent, by sticking phones across the line to hear what it
sounded like. Every time they did we got a level change, which caused a stripe
on the picture. Also the lines had poor signal to noise ratio. We had expected
this, and sent the whole picture information compressed into a range of 12 Db.
It was brought back to its original state by adjusting the intensity of the Lightvalve illumination.
Things went badly for a time. The
Eric Vast
July 1994
The actual printing of the picture by the big presses was done by the Half Tone process, which in these days was almost unbelievably complicated, ( it probably has little changed over the years ). It is still extensively used. The picture is made up of little black dots of various dimensions to build up the picture. In a good half tone the regular spaced dots are upwards 50 to the inch in exactly square layout. Where the blackest part of the picture occurs the dots just touch; at lighter tones the dots are smaller and the white of the paper shows. In the lightest parts they should be just about disappearing. Commonly you get a range from no dots at all, to a blob of ink with dots only visible in the intermediate tones. How this is done is interesting. A photograph is set up and a negative is made of it through a screen bearing the appropriate number of holes; in my day this was done on the old wet plate. A sheet of glass was coated with collodion, stuck in a dish of Sodium Nitrate solution, ripened in some devil's brew and exposed. These plates had no grain. The picture thus broken up into little dots was then projected, using an arc lamp, on to a zinc plate coated with a mixture of gelatine and Potassium Bichromate. The light makes this mixture tough and less soluble in water. The plate was then exposed to a spray of Sulphuric acid, the softer gelatine being washed away, and the etching process started. The plate then was covered with spots of gelatine of various sizes and toughness and etched areas of zinc. At this time it was washed in water, and dusted with a cloud of mainly resin particles, which adhered to the dots of gelatine giving added protection. Etching then restarted and then the plate began to resemble a field of tiny mushrooms on conical stalks of different heights. The trick was to stop when the tops all fell off, leaving a landscape of sharp little cones of various heights. these when inked and pressed into the paper by the big presses.
The picture plates were then made up into flat assemblies in a sort of frame with the letters of the text. and sent to the Stereotypers. These people made an impression of a flexible slab of material which could be bent to the shape of the printing rollers. It then went to the foundry and printing rollers were cast. It was rather a marvel that the results were as good as they were. Printing ink had to be spread evenly on the rollers, being pressed over a number of small rubber faces ones in series. It took a fair time to get things right, and the ceremony of running up, wasted many copies of the paper. Ocassionly a roller might be changed with the presses still running slowly to keep the ink supply from getting mucked up. Men would get inside the massive working parts, and slip a fresh roller on. This was dangerous, and I doubt it is allowed nowadays.
I went to
The customers were throwing empty bottles against our wall. We suffered from
this also in
After about a year things got very routine and having heard that our colleagues in Bush House were seeking engineers to install the new Talkies, I allowed myself to be lured away to sample the joys(?) of travel, generous expenses, and an unlimited supply of Usherettes. It had been a very interesting year, at least I had learnt to solder properly.
MY
YEAR
( Part 2 )
As the general tarting up of the building was still going on, nobody
except a few Top Brass got a fixed office. I got
shifted in to share with lesser beings a number of times. Once I was put in
with the famous 'Beachcomber' of that time. I don't think he really liked me,
he never replied to my morning greeting, and when I was there he studiously
read the newspaper. Another character was a hoot, he
had new ideas on everything. I remember I was harangued on the errors of
The one day the equipment was sighted in London Docks. The Customs and Excise did their usual act. The promptly claimed that the device was a camera and should be charged duty at some enormous rate. In the end we paid duty on a few not very expensive lenses only. I was to see them trying the same trick years later when the first Ampex Video Recorder was imported by AR. That time the tried to prove the machine was a Musical Instrument.
The gear was
shipped from the docks to
However we had by no means heard the last of the stranded wire story. The master plan called for the main earth to be solid ASWG gauge 3 conductor, and an insulated one at that. This took months to arrive and 36 ft of it duly appeared, and was connected firmly to an incoming High Pressure Hydraulic Main, which supplied the lifts which carried the big rolls of paper from one level to another.
When set out the equipment was found to be nicely made . As received it was intended for the source to be a Transparency, this was made to rotate and move along a lathe bed by the action of a lead screw with 100 threads to the inch, plus a rotating splined shaft for the rotation. It could operate in either direction. A spot of light was focused on to the film, and a photo-cell was placed inside the rotating film to collect the signal. It was nothing special, but as its sensitivity was only 2 microvolts per lumen, it was an early potassium one. There was plenty of light from the spot to provide a sensible signal. The cell current passed to a DC amplifier made up of many Dry batteries and a few resistances, which was an absolute so-and-so to set up. It was however stable enough when finally adjusted. The signal still having the DC component then passed to a modulator, where it took the audio carrier frequency.
The drive for the carriage was a two-phase 115 volt 60 Hz motor of low power produced by a 60 Hz tuning fork. The motor was a fly-wheel of lightly made metal, and contained some 14 lbs of mercury. This enabled a start to made with a dog-clutch, as the light flywheel could quickly accelerate, and the liquid mercury could catch up a few seconds later. The motors were not self-starting, but they could run in either direction if brought up to speed with a modified hand-drill. They had I think 20 pairs of poles and ran quite slowly. It was easy to run them up to speed and they locked in readily.
The master
tuning fork in
Once during my
stay with the 'Express' there was great excitement as the
The actual
recording device which varied the amount of light falling on the photographic paper, was a typical Bell Labs 'Lightvalve'.
This had a single dural ribbon flanked at each side
by knife edges not quite in the plane of the ribbon. The ribbon was in a very
strong magnetic field, and was tensioned to resonate at the carrier frequency.
This might have expected to have given a heavily peaked response, but the high
magnetic field kept it down to a few Dbs ( or TUs as they were then ).
During a period of operation deep red lighting was used. After some hours in
this it seemed to have changed to a rather nasty shade of pale pink.
The Post Office
provided a four wire system of lightly loaded cable for the system. It had
hoped to get unloaded lines, but these we could not have. The small loading
coils gave as expected a low pass filter effect which included a phase shift,
which the long run to
There were I think at that time 14 repeater stations between us and Glasgow. For the first weeks of transmission they spoilt nearly half the pictures sent, by sticking phones across the line to hear what it sounded like. Every time they did we got a level change, which caused a stripe on the picture. Also the lines had poor signal to noise ratio. We had expected this, and sent the whole picture information compressed into a range of 12 Db. It was brought back to its original state by adjusting the intensity of the Lightvalve illumination.
Things went
badly for a time. The
The actual
printing of the picture
by the big presses was done by the Half Tone process, which in
these days was almost unbelievably complicated, ( it probably has little
changed over the years ). It is still extensively used. The picture is made up
of little black dots of various dimensions to build up the picture. In a good
half tone the regular spaced dots are upwards 50 to the inch in exactly square
layout. Where the blackest part of the picture occurs the dots just touch; at
lighter tones the dots are smaller and the white of the paper shows. In the
lightest parts they should be just about disappearing. Commonly you get a range
from no dots at all, to a blob of ink with dots only visible in the
intermediate tones. How this is done is interesting. A photograph is set up and
a negative is made of it through a screen bearing the appropriate number of
holes; in my
day this was done on the old wet plate. A sheet of glass was coated with collodion, stuck in a dish of Sodium Nitrate solution,
ripened in some devil's brew and exposed. These plates had no grain. The picture
thus broken up into little dots was then projected, using an arc lamp, on to a
zinc plate coated with a mixture of gelatine and Potassium Bichromate.
The light makes this mixture tough and less soluble in water. The plate was
then exposed to a spray of Sulphuric acid, the softer gelatine being washed
away, and the etching process started. The plate then was covered with spots of
gelatine of various sizes and toughness and etched areas of zinc. At this time
it was washed in water, and dusted with a cloud of mainly resin particles,
which adhered to the dots of gelatine giving added protection. Etching then
restarted and then the plate began to resemble a field of tiny mushrooms on
conical stalks of different heights. The trick was to stop when the tops all fell
off, leaving a landscape of sharp little cones of various heights. these when inked and pressed into the paper by the big
presses.
The picture plates were then made up into flat assemblies in a sort of frame with the letters of the text. and sent to the Stereotypers. These people made an impression of a flexible slab of material which could be bent to the shape of the printing rollers. It then went to the foundry and printing rollers were cast. It was rather a marvel that the results were as good as they were. Printing ink had to be spread evenly on the rollers, being pressed over a number of small rubber faces ones in series. It took a fair time to get things right, and the ceremony of running up, wasted many copies of the paper. Ocassionly a roller might be changed with the presses still running slowly to keep the ink supply from getting mucked up. Men would get inside the massive working parts, and slip a fresh roller on. This was dangerous, and I doubt it is allowed nowadays.
I went to
After about a year things got very routine and having heard that our colleagues in Bush House were seeking engineers to install the new Talkies, I allowed myself to be lured away to sample the joys(?) of travel, generous expenses, and an unlimited supply of Usherettes. It had been a very interesting year, at least I had learnt to solder properly.
Eric Vast