1931-08-27 — Page 2

HONG KONG DAILY PRESS, THURSDAY, AUGUST 27, 1931.

Listen -

If

RADIO

you want Best British Components, it is undoubtedly

1ISSEN

TRADE MARK

WE KEEP REGULAR STOCKS

AND

ACCEPT

FORWARD

ORDERS.

Apply for Catalogues

THE SINCERE Co., LTD.

SOLE DISTRIBUTORS.

HAVE YOU HEARD THESE?

Here are lists of long-wave and short-wave stations” which, should be picked up by anyone in Hong Kong who has a moda. ratály good set sultable for re- ceiving auch signals. Success in plaking up these, stations, aland depends very largely upon,tav- ourable atmospheric conditions Readers are invited to add to this list should they succeed in picking up any station not in cluded in either of these lista.

LONG-WAVE STATIONS.

Ware 'length

Call Kilo (Metres) Station Bign cycle

960 Manila

E.ZI.B. 1,153 277" Shanghai

K.S.M.S. 1,083 345 Tokyo 1.0.A.K. 870 333 Hiroshima J.O.F.E 810 355 Hong Kong Z.B.W.

948 357.1 Bombay Y.U.B;" 940: 1.0.1K 830 TO.DK 20. J.0.0.K. 1810' 7.0.0. 800

361 Sapporo

268 Keijo

370 Nagoya 370.4 Calcutta

380, Kumamoto J.O.G.K. 700 300 Bendai KJ.O.ELK. 770 895 Dairen 400 Osake

410 Canton. 480 Manila

SHORT-WAVE STATIONS.

STATION

CALL 810%

A.F.K.

37.68 Delinte (Germany)

60.29 Khabarovsk (Busain) 21.07.

50. 48.6. Bome

Naucu Моко

4.

Porth

41.8

Bingapore

பிம்

JQAK 780: J.O.B.K750 C.M.B.. 739 K.ZEM. 825

Tina (Hoxe Komα)

OF WORKING

FEATURES

HMV TACKLES TELEVISION.

INTERESTING DESCRIPTION C OF NEW SYSTEM.

Much has been done by research workers all over the world to bring television, an already Bocomplished fact, into tão realm of practical politics, but there is still a long way to go before this branch of science becomes of use to the average man. The latest developments have come from an unexpected quarter-the great Gramophone Company's, factory and research works up; Hayes. An account of the system of television developed there is given below.

[BY A CORRESPONDENT.]

It is a long time since we have state of the ether would make it heard anything much about tele- essential that short waves, be used vision, either in this country or if radio were to be a medium of abroad, and one is

to transmission of the I.M.S. system system imagine that lack of news on the of television. subject means lack of interest" ön the part of experimenters and re- search staff.

Land-Line Dimenllies,

Land-line work on long distances on this system of television is also difficult, because under the scheme, as it was shown to me, & band of over 23,000 cycles per second on

;י

nel. The total scanning of the five of the film projecting, shaft which sections is reassembled on tho receiv-energises a special form of control ing seroon.

at the receiving end, There are pig advantages in using Whether anything will come of five channels, for in the H.M.V. this system remains to be acen. At system a modulation frequency of present it is an interesting labora only £3,750 is required instead of tory presentation of television, and five times that amount, and the The Gramophone Company do not design of low-frequency amplifiers wish it to be taken as anything but capable of handling with anything inboratory experiment at the mos liko A straight-line relationshipment.

such high frequency, though not (57) Which is Better"

"

aaay, is rendered more prácticable.; The question in readers” minds Five-Sectional Scanninge. that will immediately rise is " Is

Tho Alm is passed through a

the HMV kystem se good as the cinematograph of the usual type, Baird There is no direct answer the light from it baing reflected to this. It is entirely different in through a series of lenses on a reconception from the Baird system, volving drum, which for every re-and the two can hardly be compar volution completely scans the pic- ture in five sections.

•The light

In order to obtain successful pro- jection about sixteen pictures per second or a little more are used on the

ordinary cinema, when no flicker is noticeable. Occasionally one can reduce the speed down to

reflected through the The result of the H.M.V. system about, twelve Pictures per second revolving lenses is thrown upon as shown to me le rembly before the eye will notice fickor..

Therefore, it will follow that in five photo-electric cells, each taking picture where there are perhaps care of its own section of the pie ten thousand small dots, each of ture. theas small dots must be reproduced

ed.

brilliant and clear, the sections do

not blond quite properly but would be grossly unfair, to both sides if I were to say here are two symtoms of television; this

That this is not true is shown by the fact that I received a tele phone call from the Gramophone Company (H.M.V.), and to ing utter astonishment the object of the each channel was covered, neces-twelve times a second in order to call was to invite me to bomo, down/sitabing not only a special design give the transmitting image the valves, and the signals from these better than the other."

ا ہے۔

and see a" now system of televisioned amplifier, but highly efficient illusion of moving, and still to which had been evolved at the land lines. Over short distances make use of this persistence of

vision to H.M.V. factory, -

suficient extent to avoid objectionable dickor. In

results, no doubt, would be per- factly good, but over long distances it remains to be seen how much other words, 190,000 individual mutilation would be caused by land-signals will have to be transmitted line loss.

per second...

I knew that the Research Depart ment of the Gramophone Company had been doing a lot of work on the photo-electric cell, and I knew that they had developed a very But let us go on to the technical efficient one, but I had no idea that description of the whole system, by they had been turning their atten-which you will be able to judge for

tion to television in any shape or yourselves exactly how much has

form.

The Entertainment Test.

been accomplished, though as a means of assisting the formation of your judgment I should like to So, therefore, it was with un-state that the pictures shown were usual interest that I made the short journey down to Hayes, where Mr. Dyer was waiting to show me round and to explain this development.

First of all he introduced me to the new photo-electric cell, of which H.M.V. are justly proud. It is,

11

eesiumi photo-electric cell, and was

perfectly clear and steady from the ordinary cinematograph point of view, though the blending of the five sections was not all that it might be.

Like a Printed Photograph, My readers are probably well

being shown in connection with a aware that any system of television

talkie amplifier in a comparative

test with an up-to-date commercial model of photo-electric cell of the potassium type,

A modulated neon lamp as the light sourse was being used through out the experiment, and the light

The General Arrangement. This seems a lot, but it is a 120,000 signals per second will be fact that a picture transmitted with

somewhat lacking in definition, and this is where the man who is trying to design a television system for broadcasting comes up against it. In order to restrict the frequency of the impulses to within, the band allowable by broadcasting under the present system, the number of dots per second has to be reduced, and therefore the detail of the picture has to suffer.

E.M.V., however, decided to.com- centrate their efforts on achieving

The output from each photo electric cell is amplified by the

are further amplified,

The future alone can show what

The signals are again amplified will be the ultimate end of either

by special designed amplifers, and system, and I do not intend to pro- it is claimed that an amplification phecy ultimate adoption for broad- A BEast transmission of television pra- of nearly a million is obtained;

As the intensity of th

of the trane, grammes for oither. We must wait mitted signals will vary according and ace to whether they are generated by

light spots that are bright or dark parts of the picture, the light from the are lamp, therefore, must be modulated in sympathy. This is done by a specially developed form of Kerr cell, a light-valve capable of operating at high frequencies and of handling a considerable amount of light, p

No Bash Promises. These special cella are situated ning the object to be televised at a perfect a picture as they could between the arc lamp and

yet attempted bas consisted of scan-

a rapid rate and in sending over in order to ascertain bow much

in soquence very tiny portions of entertainment value could bo secur

ing drum.

TO

This latter has on, it the picture by means of a series ed, and not primarily with any idea highly polished mirrors which cor

of tiny electrical impulses that the systems might be used on respond. exactly both in speed of

The result at the receiving end

broadcasting. Their argument is revolution and relative, position that without entertainment value with the transmitting lenses. television" is bound to fail ag" a commercial proposition, and that

from this lamp was allowed to fall can be likened to a photograph in turn

on to the commercial block, for any close examination of photo-electric cell and then on to a printed illustration will disclose

The synchronising is very simply

the HM.V. cesium cell. A very the fact that the picture is actually unless the result of their researches carried out by means of a special marked difference in sensitivity and made up of an enormous number Provides entertainment it is no dynamo mounted on the less dram in the Brillance of reproduction was of small dots which vary in size good tackling the problem at all... noticed immediately; as a matter and blackness. If there are a large

of fact the II.M.V. cell gives 4.3 microamperes per lumen as against

The general arrangement of their number of these dots for a given system can be gathered from the arca the texture of the picture is sketches accompanying this article, the 20 odd microamperes per lumen finer, and the correct tone is

one is better but before discussing these I must

of the commercial cell, so it is a achieved. If, on the other hand, impress upon you two principal great advance.

there are few dets the, picture is points in the development of that said to be course,

I was then introduced to the real

system! object of my visit, the démonstre Now the detail attained by tele

Ono is that in order to get de tion of projected television, And vision depends on the number of finition a large number of signals here it must be explained that impulsés per accond form a given per second for a given area of the H.M.V.'s have fackled the question area. If the impulses do not come picture is used, and the second is 6434 Mon, Wed & Fel., 6p.m.& 2 km of television from the entertain fast enough then the picture will that in order to get sufficiens illu 4,990 6-10 p.m.

| 5,291 || Not rögular 1991 3

6,000 Tank Thur, Sat:8 p.m.

6,300 Bunday midnight

B.FN.

6.4.G.

V.8.1.A.B.

3,780 Daily 11

·89.8 Kootwijk (Helland) PC.L

Bangkok (Siam)

32.6 Sydney,

11.55 Melbourne

|HSAPJ

2.B.LX BLO.

7,142 Daily 8.50 p.m. & 11 p.m.

7,910 Not regular

8,108 Tues & Fri, 9 pm/-1 am,

B230 Not regular

9.508 Not regular

1.2X.A.7.0,630 Dally 7 am

87.48 Babenectady 81.20 Eindhoven (Holland) F.C., 31,28 Sydney 81. Nairobi (Kenya)

Bydney

27.8Bandoeng

2.FC.

7.1.0.

PLR

25.68Chelmsford (England) 5.5.W.

28.35

Manila Schenectady

15.83 Badong

15,4 | Kootwijk (Holland)

Bandoong Bangkok

27.4

18.9

158 Kootwijk (Holland) 1874' Bandoeng

15.8

Hanoy (France)

19.08 Pittsburg

0,620 Fri 8am. Bat. 3 am, & 10 am. 9,600 Not regular

9,077 Midnight daily

3 [10,620 | Not regalarong TaM

11,020 Midnight-3 am, daliy 11,751 7.80 p.m. &'am. daily, except

Saturday and Sunday

K.I.X.E

12.210 Nightly

W210. PLC. P.O.L PALV HELPI PO PLE

12,560 4 Am, Wed, F, Sat,

10,102 Daily 6.80 p, to midnight 18,304 Daily 7 pm.

17.280 Dally 8 pm, to midnight

17751 Bundays 7pm, & midnight

Rach

afternoon

18,404

19,200 Daily^2/30—1

10,351 Dailym

WALK. 71,340 | Not regular:

„time !!« in mari «Euro-

ment point of view rather than flicker and become blurred, and ifmination for the imaging so that from the scientifio wonder a

as there are not enough impulses per it can be said to possess entertain- pect, and they have attempted to square inch then the detail will be ment value, some means of modů. develop a system of televised lacking. cinematography that in the future might be exploited for use for the broadcasting of films of test matches and other important public over 23,000 eventa

In each of the five sections of the system there are lock pond, which gives a very fine degree of definition

HM.V pulses

The transmission of television of living objects in not being attempt Now we all know the principle ad at present, I understand, but on which the motion picture camer there is no doubt that. H.51.V's and projector operate and this

got over a very good representation principle must be considered when

R

lating light, had to be found. *

A comparatively feeble illumine tion as displayed by glow discharge famps (such as the neon type) which have frequently been used have not

proved themselves, sufficient. The

set themselves the problem of, cm- Gramophone Company, therefore,

ploying the light from a powerful

that would actually control the are lamp, and designing apparatus

of film, projected on to a screen dealing with transmission of mor-light from this source.

so that a large audience could seeing objects by televisión.

-it-

In order to get definition, every||

It is based on the fact that the large number of dots or points of Whether the system will over be eye attempts to retain an image light are employed, and in order practicable from a radio point of after the actual object, has been reto redues, the total number dots view remains to be seen, because moved. This is know as “permat, par second the picture was divided five channels are used, and this enes of vision," and no moving into five sections, each section being would mean five "separate wave picture would be. ssible without scanned separately and the lengths So the present congested this peculiarity

Transmitted along a separated chán.

Popular Wireleis,

A LITTLE

care in setting up an advertisement often doubles its selling power.

It is that little extra thought and care, which g given to advertisement drawn up in the office of the Hong Kong Daily Press, which brings good results

every

G.I.C. DOUBLE-BUTTON CARBON MICROPHONE

Front

Faithfal Reproduction

on Voice and Musical “Frequencies.

Frequency

Response Corve uniformly flat from 80.7,000 cycles per second..

Public Address Ampli- flors, Giant Dynamic Horns and Induction Dest Motors are all available:

APPLY T

THE WING ON CO LTD.

28871

Distributors

Radio Depa