1931-08-20 — Page 2

HONG KONG DAILY PRESS, THURSDAY, AUGUST 20, 1931.

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FEATURES

RADIO COMMUNICATION AND BROADCASTING IN THE U.S.S.R.

ERECTION OF 500 KILOWATT TRANSMITTER PROJECTED

NEAR MOSCOW.

A BAND-PASS FILTER.

Those who have tried a sat having

NEW TRANSMITTING SYSTEM.

aband-pass filter will, no doubt, TRY-OUT ON S.S. PRESIDENT

have noticed double-hump tuning. This indicates that the circuits are out of tune or else the coupling is too tight.

HOOVER

The new Dollar liner, 1.8 Presi, dent Hoover, made radio history an Attention to the ganging of the her sailing day from New York by two airenits forming the tuned being the experimental field for the Alter may put matters right, but

initial tryout of a new system of if you find that the pronounced fight pulsations that enable ships in transmitting sound by means of double humps continue, then the harbour to carry on secret and direct communiention with some action effect may be partly respon-

other point.

sible for the poor tuning, or thereing." was tried out for the first The system, called "Narrow Cast may be stray couplings.

time when music and voices were

The use of the radio for commertrains with radios. Up to the pre-t well as public speeches. In the cial purposes is increasing rapidly sent the best results have been at national republics programmes in in the Soviet Union as a result tained on the Northern Railroad. the various languages are trans. of the great economic development Furthermore, the continuous and mitted, with the view to raising the of the country. The main radio speedy development of the collecti- | cultural lovel of the population." centres are Moscow, Leningrad, vization movement in agriculture; As a result of the widespread (Urals), Khabarovsk (Far East), radio network to all agricultural working mansees a special section Tashkent (Central Asia), Novosi- centres, not only for amusement for home-study courses has been birsk (Siberia), and Tiflis (Trans- and educational purposes, but as established at the various radio bauendia). 'In addition there are a means of keeping the members of centres. The so-called radio uni other centers of secondary import collective farms informed of econo.versities are organized on a large mie progress throughout the coun scale. There is also a special de partment which handles correspond once from listeners in with sugges- tions for improvements, etc.

Kharkov (Ukraine) Sverdlovsk makes it essential to extend the desire for education among the coupling should be reduced. Re

ance.

Million Subscribors.

In any case, a reduction, in the carried across the Hudson River coupling will produce the desired from a transmitter projector en

Pier 201 result, bringing the humps together President Hoover, the distance, to receiver in the now

Band-pass circuits are very inter being approximately 3,000 feet. esting and much time can be spent Static does not a affect the new in finding the best valuedio waves are millions of times

medinm of communication..

For testing, a meter connected

District - centres and important | try.. cities have broadcasting stations Local broadcasting stations are varying from 1 to 100 kilowatts responsible for working out pro capacity. There are now forty-seven grammes

and

ascertaining the broadcasting stations in the coun-special interests of the local popa- try. The main stations in Sverd-lation. They are algo in charge of Thero are now more than 13 -lovsk, Tillis,-Kharkov-and-Tashkent- all technical equipment both for million licensed individual radio in the anode circuit of the detec- are of 25 kilowatt enpacity, while commercial and broadcasting sta-subscribers at present in the that of Khabarovsk is a short-wavo tions. transmission station of 20 kilowatta with a wave length of 70 metres.

Central radio advisory councils are formed from representatives of the various social organizations. These councils usually meet month

longer than the light bean waves.

The latter travel in straight lines. U.S.S.R. The fee for crystal sets tor is valuable. Do not overlook Beams from a powerfni Neon tube; is one rouble, & year and for valve the fact that the resultant tuning actuated by electrical vibrations sets three roubles. In this connee curve depends upon the characteris graph and radio receiver, hire car- generated by microphong phono tion, it should be borne in mind ties of all the tuned circuits ried by the waves Beams are that, unlike in

Amerien and

.1

رهم

The Moscow broadcasting centre has three stations of 100, 40 and 20 kilowatts, respectively. The erec-ly to receive replies to questions Western Europe in the Soviet

If, therefore, the filter circuit in focused by means of a concayo giant 500 kilowatt concerning the compilation of pro-Union collective listening-in is in the nerial and e tuned inter-mirror, at the distant receiver. station is projected near Moscow, grammes and to examine the broad- much more general, for-instance, in valve coupling, is used, be sure to which will be the most powerful in casting network. Programmes are the thousands of clubs, reading. note the combined effect, rather atmosphere and concentrates them At the receiving end A conver mirror gathers the rays from the arranged as far as possible to con- rooms and schools. In addition to

tion of a

the world.

form to the requests made by the the crystal and valve receivers in than that of the filten alone. The out a sensitive photo-electric cell A listener-in ibis way there is the U.S.S.R. there are loud speak best scheme, naturally, is to have

THE SINCERE Co., LTD. casting stations throughout the popular control of the content of ers at central points in cities, single-knob tuning.

SOLE DISTRIBUTORS.

HAVE YOU HEARD THESE?.

LONG-WAVE STATIONS:

Kilo-

Hera B16 Hats of long-wayU .... "and" short-wave stations which should be plaked up by anyone in Hong Kong who has a mode- rately good set multable for re-- ́ceiving such signals. Success in picking up these stations also depands very largely upon fav - ourable atmospheric conditions," "Readers are invited to add to

this list should they, sucoeed-in-- ploking up any station not in cluded in either of these lists.

Wave length

Call (Metres) Station Sign cycle 200 Manila 'KZIB. 1,153 177 -Shanghai H.S.M.S. 1,883 345. Tokyo J.O.A.K; 870 333 Hiroshima J.O.F.K." 800 355 Hong Kong B.W. 846 357.1 Bombay

V.U.B. 840 J.O.LK.. 830 J.O.D.K. 370 Nagoya "J.O.C.K. 370.4 Calcutta. V.U.C.

361 Sapporo

388 Keijo

820 BIO

800.9

Programmes.

LOW LOSS,

powerful amplifier is used to in-. crease the effectiveness of the result- ing electrical vibrations correspond- ing to the music of words sent out by the transmitter and these are. re-created in a loudspeakers

The General Electric Company, Although low-loss constructions which installed the engines and· are not now given as much atten- sonte electrical devices on the Presi tion as a few years ago, the need dept Hoover conducted the experi for avoiding the use of materials having doubtful electrical proper ties remains.

The Five Year Plan provides for the construction of sixty broad

U.S.S.R, varying from 10 to 100 the radio programmes.''

towns and villages, These may be kilowatts in size. The parallel

Been at street-car terminals, public growth of telegraph, wireless and

squares and buildings of import cable services provides the pos The main programmes comprise

ance. The number of listeners in sibility of interchanging methods of special items for workers, peasants, | communisation, should this be desir women, youth and army organizas expected to be 14 million by

1933. ed. This is already done in case of tions, etc. Musical programmes

The

Society of Friends of the events of great social significance. alternate with "general political The Five Year Plan also provides programmes,

lectures in Radio publishes two journals which for radio-telephone and television foreign languages, talks on health, appears every five days, the Radio service for all the basic centrés. . At'] etc. In addition to the special pro- Froat and Radio in the Fillage, present there is only one radio-telegrammes, there are those of a gen- Clubs and, schools throughout the phone, servies in the country, that era artistic nature orchestras, country have special study, circles

Cardboard is, for instance, some between Moscow and Sverdlovsk... singing, ste. Every evening special for instruction in all branches, of

Radio on Trains. *

events are broadenst from centres radio work and every encourage-times used for coil formers. This There is a general drive being of public entertainment, such as ment is given to students to join may be satisfactory, but will prob made to provide all long-distance concerts, operas and plays, as such circles.

DUAL RANGE COILS,

TOWE,

TRANSFORMER TROUBLES,

ably not be unless it has been care- fully treated. Good quality chonite and bakelite formers are worth using for coils which will be Atted"

ments.

What do

you want ?

JBothere Anything you want 20 buy or soll,

xinall Ulasified advertisement.

for 3 Insertions.^

Compact coils are sometimes not very efficient, although perhaps

It is often supposed that the front of reasonable efficiency.25 words $1.00 prepaid they are quite good for their size,

Most of the prepared tubes are suit- core of transformers and choking In many circuits we use a dual- and this point of the best serial

coils ought to be so well made that able, too. range coil having a tap on the connection is bound to crop,Pair gaps do not exist. This is not J.O.E.K, 770 medium-wave call for ths aerial. Sometimes a single separate aerial true when a direct current is pass-

This tap is useful, as the selectivity winding is used for both wave and magnification are both prob. bands, but here again something ably better when the serial 18 take is lost in the interests of simplicity to the tap instead of to the top | and cheapness.

360 Kumamoto J.0.G.K. 700 300 "Sendai

305. Dairen

· 400 . Osaka

410 Canton 480 Manila

- SHORT-WAVE-STATIONS.

STATION

CALL SIGN

67.05 Doblets (Germany)

60.12 Khabarovsk (Russia)

Namonw Mosco

06.7.

20.

40.6 Bome

Parth

41.3

Singapore

38.8 Kootwijk (Holland)

Bangkok (Ulam)

87.

Sydney

81.65

Malbourno 31,48 Schenectady

KILO

780

J.Q.A.K. J.O.B.K. 750 C.M.B. 739 K,Z.R.M. ten

Tixx (Hoxa Kora). OF WORKING

of the coil.

A.F.K.4,434 Mon., Wed. & Fri, 6pm, à 2 nu B.A.97. A.G.J.

R.F.N.

1.MA.

10.4.0.

4,000 0-10 pini

8,291 Not regalar

6,000 Tue, Thurs, Sat. 8 p.m. 6,590 Banday midnight

7,143 Daily 8.30 pm & 11 p.m. 7,810 Not regular

9,509

pm

1.9.1.4.E. P.C.Li

7,980 Daily 11 HS4PJ.,

8,108 Tues. & Fri., 0 p.m.-1a.m. 2.B.L. 9,980 Not regular 8.1.0 W.2.X.A.F. 9,630 Daily 7 a.m.

2.F.C 7.1.0. P.M.E. PLE

81.20 Eindhoven (Holland) P.C.J,

81.28 Sydney

81.

Nairobi (Kenya)

$23.6

$23.6

Bydney

27.8

Bandoeng

25.43 Chelmsford (England) 6.9.W.

245 29,85

Manila

with #

Sobenectady

18.4

Kootwijk (Holland)

ELKE W2XO. P.L.G. P.C.L

17.4

Bandoeng

P.L.

10.0

Bangkok

103,8

Kootwijk (Holland)

ELBI.PY. FCK

16.74 Bandoong

P.LE...

165 Nanoy (France)

18,68 Bandoeng

2009 Not reguler 9,620 Fri, 3 am, Sat. & am. 4 10 a 0,590 Not regular

0,077 Midnight daily

10,696 Not regular 11,020 Midnight-8 am, daily 11,761 7.80 p. & 2 a.m. dally, except

Baturday and Sunday 12,340

Nightly 12,550 4a.m. Wed., Fri, Sat.'. 16.102 Dally 6.80 p.m. to midnight' 16,004 Dally 7 pm

17530 Dally 8 pm to midnight 17,761 Bunday 7 pm,& midnight 18,404 Each afternoon 19,820 Daily BG-7.p.m.

19,861 Daily B «ii.

[Allowanow must be made forammer-time in meet. Eztro- porn countries, which is one hour ahead of trus time.)

The wavelength range with a given tuning condenser is greater... too. This is because the effect of the capacity of the aerial is re- duced by reonuecting it to the tap. Now, these advantages are usually not obtained when we switch over to the wavelengths, for the reason that the merin is not connected to a tap on this coil.

THOSE MAINS--VALVES,

ing through one of the windings as well as the alternating current.

Both transformers and shoking coils should have the highest in

ave the highe ductance under working conditions?

It is true that the greatest induc Should we use A directly or antive effect is obtained when the directly heated power valve in an direct current is very small or when A.C: Bet?

thero is none at all. X

#

Given a good and suitable direct,. But in practice the current may 15-henated power valve, the hum is be, say, 3 or 4 milliamperes in the negligible, being hardly heard at case of the intervalve transformer all The characteristics are as and perhaps 20 or 30 milliamperes

are good as a rule, as those of the in-the case of the choking coil. indirectly-heated type, and valves Tests show that in many instances working with an anode voltage of the greatest inductance under the 200 and giving a good power dut working conditions is obtained by put are available.

providing an air gap.

Simplified switching is respon sibic, and you cannot obtain the bent possible results without making

A centre-tapped transformer or It is possible, in fact, to obtain the medium and long-wavelength

a wire potentiometer of low resist a fairly uniform inductance over, circuits in the best way. In the ance say be used, and grid bias a range of direct currents by care- Binowave coils, separate long and

may be obtained by Including Irally proportiozí medium-wave aerial connections are

"resistance in the high-tensión nega- gap, and number of turns In used in order that the efficiency of tive return in the usual The

practice the gap is provided by

rap is provide the coils shall be high on both ware

fitting a thin piece of fibre or other. centre top trust be fairly accurate,

material at a joint in the magnetic or a hum may be heard

G.L.C. DOUBLE-BUTTON CARBON MICROPHONE

Front View

Rear View

Faithful Reproduction Voice and Musical. Frequencies.

Frequency Response Curve uniformly flat from 80-7,000 cycles per second,

Public Address Ampli Bers, Giant Dynamic Horns and Induction

Desk Motors are all available.

THE WING ON CO., LTD.

Distributors.

Radio Department..