1930-07-10 — Page 2

HONG KONG DAILY PRESS, THURSDAY, JULY 10, 1930,

RADIO

FEATURES

RADIO AND THE TALKIES.

HIGH-POWER ELECTRIC REPRODUCTION.

Much has been said in the course of the last two or three articles in these columns of the construction" and action of the snagnetic pick- up, and its application to a radio amplifier. It is to be assumed,

[BY COHERER."]

the valves in the final stages being a matter for the utmost care.

Talkie Reproduction.

M

Large gramophone discs of about eighteen inches diameter carry the recorded sound of a reel of film,

From radio to the talking pic-each reel having its own disc. The lm projector has incorporated a ture may seem to many a rather fer cry, but to those who have pick-up and turntable which is

therefore, that the majority of teken more than the average in. geared to run in synchronisation |

Д

readers have now at least elementary understanding of the principles involved in electrical' reproduction of sound and its am- plification to the audio stage. "

The selection of a suitable ampli-

•fer depends a great deal on the pick-up employed and the amount of volume required. For ordinary home use a straightforward trans- former-coupled low-frequency au- plifier of two от three stages is sufficient and, as already stated, the low-frequency stage of a radio receiver answers" the purpose quite

well.

Factory-made amplifers, special ly constructed for electric gramo- phones, are apt to present a rather formidable maze of wiring at Arst sight, "especially when incorporat ing a unit for mains supply.

with the passing of the film over terest in radio reproduction, the

the projector lens Duplicate pro- relationship is obvious. So closely allied are the principles involved jectors are employed and as the film in radio, gramophones and the and disc of one run out, the other, talking picture that a few remarks on which the second film and dise the latter under such a heading has been placed in readiness, is as "Radio Topics" will not he automatically switched in.. (Hence the slurring sometimes noticed in considered out of place by the

the middle of a film when the turn- majority of radio enthusiasts.

table fails to reach its normal

Sound synchronisation of moving pictures was first attempted by speed immediately.) Herr Myster more than thirty years ago, prompted, no doubt, by the development of the gramo

Herr

The German inventor. Vogt, was the first to meet with success about seven years ago in demonstrating a perfret speaking film.

Film Recording..

A more modern method is the

HAVE YOU HEARD THESE?

Hare are lists of long-wave and short-wave stations which should be picked up by anyone in Hong Kong who has a mode- rately good set suitable for, re- ceiving such signals. Success in picking up these stations also depande 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- chuded in either of those lists.

31.48

LONG-WAVE STATIONS.

Wave length (Metres) Station

960 Madila 977 Shanghai 280 Tientsin 310 Shanghai 300 Peping 345 Tokyo- 353 Hiroshima

368 Keijo

370 Nagoya 870.4 Calcutta

SHORT-WAVE STATIONS.

STATION

CALL 8103

1L.O.

AN AMATEUR'S RECORD OF STATIONS PICKED UP.

The following stations have been recently picked up by the owner of a Loewe F.E.63 set, fitted with a short-wave adapter. Other amateurs may like to try their luck in getting these sta "tions, and we shall be pleased to publish any details relating t "Gall Kilo-

Siga

the result of their efforts. cycle K.Z.İ.B. 1,153 K.S.M.8. 1,0885 C.R.C.

List of Stations in the Far East.

Wave 1,070

Lengths. 200 m. 277 m.

Readings. Difference Left. Right. re Taiwan.

Remarks.

7-8.30

Do. Before

E.R.C. 967 C.O.P.K. · 945

Stations and Coll

Sigus.

Manila KZIB

385 Hong Kong

J.O.A.K

J.O.F.K. Z.B.W.

BTO 534

Shanghai KSMS

13.3 15.3 17.7

19.7

Very rarely.

19,9

-15.1

Do.

Tientsin

CRO

303 m.

93.5 26.1

-8.0

846

357 Bombay -V.U.B. 840

Bangkok

11PJ

300 m.

..23.5

26.1

-8.9

Wed. & Sat.

Shanghai

NFS

010 m. 25.9

28. S

Rarely.

361 Sapporo,

345

Dairen

399 Rangoon

J.0.1.K 830 J.O.D.K. €20 J.O.C.K 810 Y.U.C '800.9

790 380 Kumamoto J.O.G.K. 390 Sendai J.O.H.K. 770 J.D.A.K. 760 V.U.R." 754

Peiping COPE

320 m.

28.4

31.5

-3.3

Very faint.

Shanghai KAC

029 mi

30.7 33.9

-1.1

Regularly.

Taiwan

JFAK

333 m.

31.T

33.0

0

Tokyo

JOAK

345. m.

34.4

38.2

3.2

Japan (1) JOFK

353 m.

36.4

·40.4

3.4

Do.

Hong Kong ZBW

355 m.

37.1

40.9

*5.9

Regularly,

Bombay

7BY

357 m.

31.7

41.3

0.5.

Till 1 a..

400 Osaka

J.O.B.K.

750

Sapporo

JOIK

381 m.

38.9

42.6

7.6

Before 9.

410 Canton

413 Manila

Q.M.B. K.ZB.M

Kyoto

JODK

365 m

30.4

43.6

5.6

Do.

732

Nagoya

JOCK

370 m.

40.5

45.2

10.0

Do.

790

Calcutta

Shanghai

Trax (Honu Koxo) OF WOLKING

TCA SSC Kumamoto JOGK Hangchow IGY Sendai JONK Dairen JOAK Rangoon 7NR

370 m.

40.5

$3.0

10.0

Up to 12.30.

18

370 m.

40.5 45.0

10.0

Very rarely.

380 m.

42.0 47.7

12.7

Before 10.

300 m.

429 47.7

12.7

Not found.

300 m.

43.3

30.2

13.4

Before 10.

305 m.

40.6.

51.7

18.7

398 m.

47.3

$2.8

17.6

Osaka

Mukden Manila Nanking KYZ

JOBK COMK KZIM

400 m.

47.8

53.0

15.1

Before 10.

410 m.

50.3

55.8

20.8

-Canton

Harbin сонв

UMB

413 m 429 r. 435 m.

31.0 50.6

21.6

52.3

·69.3

93.5

Regularly.

56.6 €2,6

Except Tues.

445 -

59.0

85.2

30.2

Manila Tientsin

KZBM

480 m.

67.9

74.7

· 30,7

COEN

485 m.

68.0 73.9

39.7

Nanking

XOW

400 m.

€9.9

77.4

494

Japan (1)

JOJK

490 m..

52.9

58.9

Hauchow(1) XGY

415 0.

$1.2

57.0

Do.

European Stations.

267 7

15.8

17.7

Music

2-3 a.m.

353 in Y

36.4

40.7

330 m ?

43.0 47.9

43,0 50.0 433 m. 61,0 07.7 392 m. 45.8 51.1

Talking Music

12-1 a.m.

382 m.

44.7 48.5

Talking

2-3 a..

KILO:

4,434 Mon., Wed & Fri, 6 pan. & Jam. 4,990 6,291

8,896 Sunday midnight

7,143 Daily 6.80 p.m. & 11 p.m.

7,370 Not regular

7,730 Daily 11 p.m.

6.108

Tuen &

& Fri., 9 p.m.-1 a.m. 9,930 Not regular

9.503 Not regular

W.2X.A.F. 9,530

P.C.. 31.30

phone. The idea lay, dormant for light film. With this, the sound a number of years, and it is rea sonable to assume that it was the is recorded by means of n 'varii- perfection of radio amplification tion of light and shade on a separ that brought the talking film out ofate film. "This film is illuminated by a small incandescent lamp as it the experiment stage.

paseca across a photo-electric coll. A little tracing of the varicus

The light penetrates the recorded eircuits, however, will show that

lines on the sound film to a greater or less extent, depending on their othing beyond the last two or

densities, varying the light on the three stages of a radio receiver are

electric cell accordingly. 27,8 photo present with one two power

There are two methods by which. The cell responds to these varit stages to bring the volume, if re- quired, to a considerable strength, the sound is brought to accompany tions in the form of a current of It is the attainment of this strength the silent. film, the disc-recording corresponding density and alterna without distortion that necessitates and film-recording. most exacting" design throughout viates but slightly from the ordition, in a similar manner to the the system, both electrically and nary record electrical reproduction current leaving a pick-up.. mechanically, the construction of by means of a pick-up..

ΟΙ

"EVERYTHING

The

Alternative Methods.

The first da

From this stage the two methods are identical, the current passes to an amplifier which in turn feeds a loud-speaker or bank of land-speak. ers, usually installed behind the

GE.C. ELECTRICAL screen.

your guaranter

TENACIOUS COATING

KEEPS YOUR SET

AT PEAK PERFORMANCE

It's not the filament but the coating on it that counts

MADE IN : ENGLAND

Sold by all Wireless Dealers.

Osram

Valve

Osram Valves

with the "TENACIOUS

COATING

WRITE for " OSRAM WIRELESS GUIDE” (1929' Edition) Sent Post Free.

It is probably in this last stage that there exists the most room for improvement, no loudspeaker res ponding to frequencies of sound with the same degree of perfection, and mest, responding more faith fully to music than speech.

Tuned Loud-Speakers.

Experiments are going ahead with a system of tuned electrostatic loud-speakers, the idea being to provide a bank of twelve or more speakers each tuned to respond to a definito band of frequencies only, in a similar manner to an aerial being tuned to only one wave length..

The latest cinema projectors are now constructed to take either the dite or film method of sound-record-" ing. the latter now being accom nodated the edge of the picture film.

Recording the Sound,

It can hardly be necessary to dwell on the many difficulties pre sented in adapting the previously silent film to take sound. Syn- chronisation presented the greatest difficulty, both in the studio and In the cinema, but a very close

second was the exclusion of extrane ous noise in the original record- ing.

1

The noisy clicking cameras have now to be placed in sound-proof glass cabinets spluttering sun-arc projectors are being replaced by the alent mercury vapour lamps, atid the heary actor who could. previ ously only do justice to a part un- der the strains of soft music no .doubt has to use his imagination where the scene does not call for music. How the producer, under the sensitive car of a microphone, contrives to convey to the perfor mers his requirements, opinione, and those irate remarks usually a sociated with such people it is dif ficult to imagine.

Future Development. The electrical recording of sound on a film gives rise to considerable speculation as to the ruture develop ment of the home gramophone. It is not difficult to imagine such a practice being applied to an or dinary electric gramophone in the future. Imagine the simplicity with which, for instance, a record- ed opera or musical masterpiece,

of five

9.630

Daily 7 am

Fri. I am. Sat, 3 am, & 10...

67.85 Dobintz (Germany).

56.7

80.12 Khabarovsk (Bussis)

Nanon

A.F.E. B.A.07. A.G.J.

8-10 p.m..

Not regular

50.

Moscow

R.F.N.

6,000 Tue, Thurs., Sat, 8 p.in.

43.6

Bowe

1.M.A.

4.2.

Perth

C.A.G

41.3

Singapore

36.8

Kootwijk (Holland)

V.8.1.L.B. P.C.L.

37,

Bangkok (Siam)

H.S.4.P.J.

32.5

Sydney

2.B.L.

31.55

Melbourne

Schenectady

Eindhoven (Holland)

31.28

Sydsay

A.B.C

31.

Naimbi (Keoys)

7.1.0.

23.6

Bydney

2.M.E.

20,526 Not regular

Bandoeng,

25.53

Chelmsford (Engiand)

P.L P 5.3.W.

11,20 Midnight-3 a.. daily

11,751 7.30 p.m. & 3 a.m. daily, arcept

Saturday and Sunday

24.5

Manila

23.35

18.58

Schenectady Bardoeng

K.1,X.E. W.2.X.0. P.L.G.

19,240 12,850

Nightly 4am, Wed., Fri., Sat.

28.4

Kootwijk (Holland)

P.C.L.

17,4 38.9

Bandcong

P.L.F.

Bangkok

19.38

Kaizen (Holland)

16.3

Egote (Holland) 18.74 Bazdowoz 15.3 Nandy (France) 13.93. Pilburg.

9,590 Not regular

-0,677 Midnight daily

18.102 Daily 6.30 p.m. to midnight

18,304 Daily 7 p.m.

17.280 Dally 8 p.m. to midnight".

H.S.1.P.J. 17,761 Sundays 7 p.m. & midnight

P.E.L.

17.760 Day 10 p.is.

P.C.K.

18,404 Each afternoon

P.L.E.

19,220 Daily 5.80-7 p.m.

W,8.X.X.

10,351 21,540

Dally 8 K..

Not regulac

A RADIO with Living Tone

THE

LOEWE FE 63

9

tube

set

is one of the most effectively sensitized instruments of the age, and reproduces the human voice, and music, flawlessly.....

This set requires a Frame. Aerial only with new Barium tubes. Can also be used with LOEWE short wave attachment..

Just arrived-New Shipment of LOEWE R533 A.C. SETS.

$126 without Loud Speaker. $150 with Loud Speaker.

Demonstration Hours

11-11.30 am.

12.30-1.30 p.m. 5-5.30 p.m.

During demonstration hours expert European advice

given on all Wireless matters.

THE

record, and necesitating continual CANTON TRADING ASSOCIATION

attention to the machine to reverse and change records and needles, be ing recorded on one film that will last out the whole work without. attention, and no needle scratch las

(Other Wireless on Page 3.);

CARL SCHROTER, Manager-

5TH FLOOR, CHINA BLDG.

TELEPHONE 24810.

358 m?

Regularly. Rarely, Fairly regular Till after 11.

These can be heard on the loud-speaker," but are rather weak: There are others which are too faint for the loud-speaker.

¿TELE

FUN NKEN?

We invite Inspection

of the New

Improved Type of

TELEFUNKEN 30 W

styled

TELE

TELEFUNKEN 31W

Most Suitable for Local Reception,

0.0

SIEMENS CHINA Co..

PEDDER BUILDING, 4TH FLOOR, HONG KONG,

Showroom

LTD.

KOWLOON

TELE ยม

PEKING BUILDINGS,

KEN

27, NATHAN ROAD,

Aleo Obtainable:

Messrs..WAH MEI ELECTRIC CO., 188, Das Vaut ROAD, HUNG MING ELECTRIC CO.,:" 137, DE VUL ROAD.

~ ANDERSON "MUSIC Co.,

ST. GEORGE'S BUILDING, Ian Hour STREET.

FUN KEN