1930-06-19 — Page 2

HONG KONG DAILY PRESS, THURSDAY, JUNE 19, 1930.

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- rately good sot suitable for re- ceiving such signals. Success in picking up these stations also depends very largely upon fav- 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 lists.

43.5

RADIO

LONG-WAVE STATIONS.

cycle

Call Eilo- Sign K.Z.I.B. 1,153 K.S.M.S. 1,085 C.R.C. 1,070 E.R.C. 937

Wave length (Metres) Station

260 Manila 277 Shanghai 280 Tientsin 310 Shanghai 320 Peping C.O.P.K. D15 -345 Tokyo J.O.A.K. 353 Hiroshima' J.0.F.K. 355 Hong Kong Z.B.W. 347 Bombay 361 Sapporo 366 Keijo

310 Nagoya 370.4 Calcutta 380 Kumamoto 390 Sendai

365 Dairen

398 Rangoon "400 Osaka

410 Canton 413 Maxila

SHORT-WAVE STATIONS.

STATION

CALL 8:08

HSAPJ.

KILO

CYCLZA.

870 850 846 Y.U.B. 640 J.O.I.K. 830 J.O.D.K. 820 J.O.C.K, :810 V.U.C $09.0 J.O.G.K. 780 J.O.H.K. 770 J.D.A.K. 760 V.U.R. 764 J.O.B.K. 750 -Q.M.B. 732 F.Z.R.M. 796

TIME (HONG KONG) OF WORKING

4,134 Mon., Wed, & Fri, 6 p., & 2 a.m. 4,900 6-10 p.m.

7,310 Not regular

7,738 | Daily 11 p..

8,109 Tups, & Fri., 9 p.m.- .m.;

67,68 Dobiste (Germany)

A.F.K.

6018 Khabarovsk (Russia)

Pu1.97.

58.7

NARUS

A.O.J.

6,291 Not regular-

50.

Moscow

LF.N.

6,000 Tue., Than, Sat., 3.p.m.

Bome

1.M.A.

6,596 Sunday midnight

44.

Ferth

6.A.G.

7,142 Daily 8 80 p.m. & 11 p..

41.3

Singapore

V.S.1.4.B.

38.8

Kootwijk (Holland)

P.C.L.

37.

Bangkok (Sian)

32.h

Sydacy

2.A.L.

31.55

Melbourne

3.LO.

31.49

Schenectady

91.00

Eindhoven (Holland) | P.CJ,

31.8 Sydney

1.F.C.

31.

Nairobi (Kenya)

28.G

Sydney

2.M.E.

27.8

Bandoeng

P.L, I.

9,230 Not regular

9508 Not regular

W.2.X.A.F. 9,530 | Daily 7 Lin.

25.53 Chelmsford (England) | 5.8. W.

18.69 Bandoong

P...', B.3.1.P.J.

24.5

Manila

K.1.X.R.

28.35

Schenectady.

W.2.IO..

P.I.G.

18.4

Kootwijk (Holland)

P.C.I

17.4

Bandoeng

109

18.88

Hnizen (Holland),

16.74 Dandoong

15.6.

Nancy (France)

Bangkok

16.3 Kootwijk (Holland)

13.93 Pittsburg

P.H.I.

P.O.K.

9,620 Fri, 3 a.m.. Sat. 3. & 10 a.z. 9,500 Not reguler

9,877 night daily

10,520 Not reyalar

11,uzo Midnigbf-3 a.m. daily 11,751 780 p.m. & 3 am daily, ercept

Saturday and Sunday

12,240 Nightly 12,800+. Wod.. Fri, Sat.

16,100 Daily 030 pm to midnight 16,004 Daily 7p..

17.280 Day 9 pm. to midnight

17,761 Sundays7 p., & midright

17.789 Drily 10 p.m.

18,104 Each afternoon

19,220 Daily 5,30-7 p.m.

P.LE.

19,351 Daily 3 a..

W.8.X.K.

21,643 Not regular

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 tabes. Can also be used with LOEWE short wave attachment.

Just arrived-New Shipment of LOEWE R533A.C. SETS. 8126 without Loud Speaker. $150 with Loud Speaker.

Demonstration Hours:

11-11.30 a.m«.

12.30-1.30 p.m. 5-5:30 p.m.

Daring demonstration hours expert European advice

is given on all Wireless matters.

THE

FEATURES

THE MAGNETIC PICK-UP.

EARLY DESIGNS AND DEVELOPMENTS.

[BY COHERER.”]

Also

vibratigns could be utilised, mea- sures had to be taken to prevent its sticking to the magnet. was to be considered the fact that any rigid means of suspension would. prevent its free response.

Rubber was found to be the most. useful substance, it having the add- ed advantage of "damping" or dissipating the natural frequency or vibration of the armature.

TO-DAY'S WIRELESS

PROGRAMME.

BROADCAST BY Z.B.W, ON

334 METRES.

11 to 11.30 a.ta-Commercial Nawa. 11.30 a.m. to 12,30. p.m.-Chinese

programme.

11.30 p.m. to 2 p.m.-Programme of Victor Records by courtesy of Mesars, Teing Fook, Piano Co.

to 6.30 p.m.-Aunty Letty, Aunty Joy and Aunty Peggy will an- tertain the children.

6.30 to 9 p.m.-Programme of Vic- tor Records by courtesy of Messrs. Tsang Fook Piano. Co. 8.30 p.m.-La Ferza del Destino, Overture, Creatore and His Band.

It is rather surprising that, elce | vibrate at a certain, frequency trical reproduction of sound dating current will be set up in the coils back to the time of Graham Bell's which, when connected to a pair of original, telephone-receiver fifty head-phones, or by means of an years ago, the practice has only amplifier to a loud-speaker, will give off sound-waves of the same the gramophone been applied to

frequency as that imparted to the during the last three or four years,

It is less than four years ago that diaphragm. With a gramophone the idea of a magnetic pick-up for needle attached to the diaphragm the conversion of recorded vibra and the nail tracking over a grame tions into electrical energy was phone-record or disc in the same

Although many". manufacturers first brought to the notice of radio way as the ordinary sound-box, it amateurs through the medium of follows that the diaphragm will be still use this means of armature the wireless journals.

subjected to vibrations in response suspension such a material in an to those recorded on the disc electrical instrument has many dis-6.30 p.m.-Gems from "Bohemian which, again, are in response to advantages, the most obvious being. Girl," Victor. Light Opera Co. those imparted by sound-waves, failure to maintain a constant char- 6.38 p.m.-Soliloquy, Paul White-

The gramophone pick up, there-acteristic with time and tempera- fore, differs from the sound-boxture. inasmuch as it converts the record- ed vibrations into electrical waves

For a long time manufacturers did not secar to consider the idea worthy of development on produc- tion lines, or else it was that some time was cecessary to improve on what was originally merely a proof of the action of electro-magnetic induction.

Meanwhile many weird arrange- ments mainly of head-phone ear- pieces, rubber, and gramophone sound-boxes, were constructed by amateurs, and given the name magnetic pick-up" on the sole basis that their arrangement be- tween a gramophone turn-table and a pair of headphones resulted in a sequence of noises emanating from the latter.

Action of the Fick-up. Briefly, the action of the pick-up is the inverse of the ordinary tele- phone-receiver. As explained in these columns in the notes of April 10, the action of a telephone receiver or horn-type loud-speaker is that a varying current passing through a coil or pair of coils of fine wire placed in the field or straia of a strong magnet (thus forming an electro-magnet) will set up vibrations in a thin diaphragm

of metal placed in close proximity

to the electro-magnet..

With the current passing through the coil made to vary in response to sound waves by means of a microphone, it follows that the vibrations of the diaphragm will be

in accordance with those waves, and thus the original sound will be reproduced.

The action of the pick-up, as already stated, is the reverse of this. By ausing the diaphragm to

COPYRIGHT IN BROADCAST NEWS.

instead of sound waves.

Early Applications.

|

ל

Magnetic Damping.

The most useful departure from the use of rubber in pick-ups was placed on the market by a leading The earliest attempts at this con radio manufacturer only a few version differed very little from the months ago, suspension and damp- mengre theory of the action hereing being maintained entirely by explained. Gramophone sound magnetism. boxes were robbed of their stylus and soldered to head-phone dia- phragms in order to provide a con- nection for the needle. The tone arm flange of the gramophone unit, being fixed to the back of the ear- piece, provided a means of attach. ment to the moving tone-arm and the theory was this ready to be put into practice.

Such a crude construction was soon found to be merely a basis en which considerable experiment was nccessary before a perfect and use- ful instrument could be produced,

A complete diaphragm was "fourd to be not only unnecessary but deleterious in that it was subject to vibrations other than those im- parted by the needle. This part of

the pick-up, the correct term of which is armatear," was there fore narrowed down to a mere strip, jus sufficiently wide to cover the pole-pieces of the magnet around which were wound the coils.

-Armature Suspension.

A certain amount of difficulty was presented in finding a means of suspension for this armature, for although it was necessary for it to be in close proximity to the magnet in order that the full effect of its

DASHBOARD WIRELESS

FOR CARS.

FINGERTIP" CONTROL,

Finger-tip control of wireless sets is likely to be a feature of new motor-cars.

Motor-car receiving sets in Ameri- ea have proved so successful that makers are now fitting sets with no more concern than ordinary acces sories are provided.

The intention now is to intro duce them into England on a con-

The right of broadcasting bodies to claim copyright in the news they. distribute has been denied by the Reich Supreme Court, which upheld decision in this sense by two lower. Courts. German broadenst ing stations generally announce that the reproduction of the news in printed form is forbidden, or more recently, we should like to j aiderable scale. draw attention to the fact that. re-

The favourite design consists of a receiving, set that is mounted production of the news is not per behind the dashboard. A switch is raitted:"In November, 1928, how fitted so conveniently that the ever, as Debisfelde newspaper pub-driver of the car can operate it with no more trouble than is oc- lisher heard from the Stuttgartensioned by turning on his lights. station that the Graf Zeppelin had landed in America, and issued a special edition with the news. The German Broadcasting Company brought a test action to protect its rights. The German-Broadcasting- Company's news hulletin this even. Ling mas furorded by a broadcast -

statement in which it was an

CANTON TRADING ASSOCIATION, LTD. nounced that, as from to-morrow

CARL SCHROTER, Manager – 5TH FLOOR, CHINA BLDG,

TELEPHONE 24610.

listeners licences will be modified to make it clear that reproduction of broadcast news in writing" or print is a breach of the terms of the-licence.

For heavy work, where space is not limited, such as in the repro- duction of talking-films, a system of oil-balancing is employed.

The Differential Pick-up. The system outlined above is known as the "balanced armature"

method, differing slightly in con- type of pick up. There is another

struction though not in theory, known as the “difierential" type.

In this case the armaturé or reed, having at its lower extremity a means of attaching a needle, nasses through the centre of the coil, thereby forming a vibrating

core.

The coil is magnetically energised a in the former case, and the

strength of its energy, varying with the vibrations of the core, an elec tric current is set up in the coil.

The whole unit, 48 In the balanced-armature type, "is mount- ed with terminals on its casing, connected to the ends of the coil, and a means for tracking the in- strument over a gramophone dise

The further development of the consider pick-up and points to when choosing such an instrument will be discussed in next week's netes.

In the sets now being fitted to motor-cars (at an extra cost of from 220 to £40) it is claimed that the interference, caused by the ignition system has been overcome by ade- quate shielding and earthing, and by special filters in the ignition circuits.

The aerial is concealed in the roof is bebind the dashboard, with wire of the saloon and the loud-speaker

mesh to protect its face.

In several parts of America seri- ous protests have been made against the installation of wireless receiv ing sets on motor-care for use while the vehicle is in motion, but they have been unavailing.

r

It has been urged strongly that motorist's attention-must be dis tracted if he tries to listen to a broadenst programme while driv ing. The danger is obvious,

BUY BRITISH & BE PROUD "We have just unpacked & Shipment of

ALUMINIUM BASE-BOARD & PANELS. Suitable for Sbort Wave Receivers and other sets that require Screening

OTHER RADIO & WIRELESS PARTS (Goarantend British Made).

ORIENTAL COMMERCIAL & Co., LTD. BANK OF CANTON BUILDING,

TEL. 24405,

6.33 p.m.-Brown Bird Singing

(Haydon Wood), John McCor mack.

6.44 D.m.-Aloha Oc, Kreisler

(Violia).

man.

For Better Result

TRY MULLARD

|7:03 pin.-Do not go, my Love, THE BEST BRITISH MAKE

Marguerite D'Alverez.

7.12 p.m.-Memories

Neapolitan Trio.

of Home,

7.20 p.m.--Gems from "Pinafore,"

Victor Light Opere Co. 7.28 p.m.-La Paloma. De Gegorza. 7.35 p.m.-Over the Waves, Inter-

national Concert Ord 44 p.m.-Love's Jey, Rachmani-

noff (Piano).

7.50 p.m.-II. Trovatore (Selce-

tion), Creatore and His Band. 8 pm Chinese programme. 10.30 p.m.-Close down.

THE

MASTER VALVE

British & American Bases Available

SINCERE'S

SOLE DISTRIBUTORS

We have just received a New Shipment of an Improved Type of

TELEFUNKEN

styled

30 W

TELE {FUN}

KENY

TELEFUNKEN 31W

0.0

SIEMENS CHINA Co..

PEDDER BUILDING, 4TH FLOOR, HONG KONG.

Showroom:

KOWLOON

TELE FUN

PEEING BUILDINGS,"

KEN?

27, NATHAN ROAD.

Also: htainable:

Messrs. WALL MEI ELECTRIC CA. 185, D23 VærX Kötő, HUNG MING ELECTRIC CO., 167, Des-Vaux Boad. ANDERSON MUSIC, Co. Br. GEORGE'S BUILDING, Ion HOUSE STEKET,

TELEN FUN! KENT