1931-07-09 — Page 2

HONG KONG DAILY PRESS, THURSDAY, JULY 9, 1931.

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RADIO

If you want Best British

FEATURES

INCREASING

YOUR SET'S POWER.

A FEW HINTS ON HOW TO GET MORE OUT OF A

SMALL INSTRUMENT.

Components, it is undoubtedly high-frequency valve you will

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Those of you who have a small set have often thought how much better it would be if you could get many of the stations at much greater strength. If you add a

"valy's in crease the range and bring in more stations and also, of course, bring up the volume of those stations you already receive, but in doing this will make the set more difficult to control, since you add to it another tuning dial.

A

some sort sich 48 a potentiometer power type, because if you want connected oross the secondary to handle really loud signals and winding, because this will give a get good distortionless reception, is means of adjusting the power sup- is no use inscrting a small power plied to the fast valve.

valve in this socket. A super power, In order, to make certain that valve will enable you to handle with motor-boating and other low-fro-120 volts H.T. & grid swing of 18 quency troubles do not occur, it is to 18 volts, which is quite adequate advisable to insert an anti-motor for ordinary domestic purposes, boating device in series with the detector valve. This can bo carried out as follows. Break the lead which at present goes from H.T. positive to one side of the trans former primary in the first stage. Insert a wire-wound resistance of 20,000 ohms or thereabouts, taking one side of the resistance to H.T. positive, and the other side to the

Your volume control across the transformer secondary winding will permit you to obtain the necessary graduation in strength, and there will be no excuse for the valve being overloaded."

How to Use's Pentode.

There is a further advantage, and that is that you will be able to

BROADCASTING IN SINGAPORE.

REPORTED GOVERNMENT

OFFER:

Д Govern

Singapore, with a population of cloro on half a million people, is the only city of its size in the British Empire without then broadcasting station, but this state of affairs is shortly to be put to rights,

In a few months' time, if the scheme which is at present proposed goes through, Government will pro- vide a transmitting station and the Amateur Wireless Society of Malaya (Singapore) will provide the programmt.

Letters have passed between the local wireless society and the Colonial Office, and these reveal a desire on the part of Government

In addition, you do not increase the receiver's handling capacity, be cause that is a function of the last stage, which will naturally remain the same. Therefore, although you make stations louder, you will prob- ably got distortion on your local transformer, primary, On the trans. out down the amount of reaction to provide a station for the trans former primary side of the resist Jou are using, because of the ad-ision of news and concert pro ance, jein & &mfd. or 4-mid. conditional magnification due to themes providing that one or two technical difficulties can be-over- denser, taking the remaining ter- new L.F. stage, and in so doing you come. minal to LT negative...

will if anything get better repro- duction.

transmission due to overloading.

Adding an LT. Stage. The easiest way out of the dif- ficulty, provided you do not want to bring in more stations, is to ado a low-frequency valve which can conveniently be transformer cou- plod To do this you can build up a separate amplifier unit, or if there is sufficient room on the bass board, you can obtain a trans former, together with an extro valve holder, and modify your exist

THE SINCERE Co., LTD. ing wiring accordingly,

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 mode rately good sat suitable for TB-" ceiving auch signals. Success in picking up these stations also depends very largely upon, fav- ourable atmospheric conditions, Beaders are invited to add, to this list should. they succeed in picking up any station not in cluded in either of these lists.

LONG-WAVE STATIONS.

Call

Kilo

Wave length (Metres) Station

200 Manila 277 Shanghai

Present Valve Suitable. You will thus have a nieans of by passing via the condenser, any stray

which may act as a means of coupling through the H.T: supply, to the last valve. Remember that 4-mfd. condenser is better than 2-mid, but you can always try the lower value in parallel to make

There is another method of get tag much greater volume, and that

The Kuala Lumpur Station; P: The F.M.S. Government gave the Amateur Radio Society of Kuala Lumpur a new short-wave trans

Short Wave Transmitter..

Subsequently, on May 15, the Colonial Ofce wrote to the Bociety, under the signature of Mr. C. W Dawson, as follows:→→ In con- tinuation of my letter of February 8, I am directed to inform you that the Scoretary for Postal Affairs, S.S. and F.M.S. reports that it is extremely doubtful whether the medium-wave transmitter will be

available for use by the Amateur

Wireless Society of Malaya (Singa- pore) as proposals for its use in the F.MS are now under considerá-

tion.

"He adds that it seems probable that a short wave transmitter would be more suitable for brondenating from Singapore and that this matter is now under consideration.'

Some weeks ago an official of the Amateur Wireless. Society was in Kuala Lumpur and he was inform- ed by the postal authorities there. that "the question of installing a short-wave transmitter in Singa pore was being considered by the Posts and Telegraph, Department, ind that all that is required is proof that there is a demand for

auch a station.

is by using one of the new pen-mittter from which the Society

Heed for a Station.

Later information from a Govern-- tode valves. These valves, as most broadcasts programmes each Thes

day, Friday and Sunday, and thement source in Singapore is to the readers are aware, have five elec

Singapore society was determined trodes, but from the practical point to secure the same concession for of view ail that one has to remein- the Settlement, ber is that there is an additional

low-frequency socket,

posible that the existing var which was previously in the terminal on the base of the valve of the which is connected to H.T. positive. powers type 11 so, this can still The only point which seems to be used with advantage, but it is prohibit the use of a pentode, some advisable to increase the grid bias what, is the fact that a special out on it in order to cut down the plate put transformer should be used. current passing through the second There is nothing very terrible in

* The addition of an extra low-

forward matter than that of a frequency valve is a more straight 1)

H.F. type. There is less likelihood

of trouble, and the results from the loud-speaker point of view are usually more satisfactory. The ren son who one so often hears of cases

pore) should be asked to be respon sible for the arranging of the pro- grammes for broadcasting.

effect that Government is prepared to fit up a broadcasting station in At the beginning of the year the Singapore on similar lines to that Singapore Society wrote to the in Kuala Lumpur, and it is the Government to instal, in Singapore, Wireless Society of Malaya (Singa Acting Colonial Secretary asking present intention that the Amateur the medium-wave transmitter which was then in use in Kuala Lumpur, A letter was received from the Colonial Office, signed by Mr. C.

directed to informed you that the W. Dawson, stating: "I am

reports that though the new trenér mitter for use in Kuala Lumpur has arrived it will be some time he fore it can he brought into use owing to necessary structural altera tions to the building and the sed for thorough tests.

The Straits Time understands

in which howling, and so forth have transformer's primary winding. By this, because all that ope has to Acting Secretary for Postal Aff that the top floor of the Post

been produced when the extra traps former-coupled stage has been add

Y

Office Building is eminently suited to the purposes of transmitting room and studio offices, while acriale

are already in being.

Incidentally, the fact that

Sir

Cecil Clementi, has consented to be.

"Ho adds that he is anxious to come patron of the Amateur Wire-

ciety of Malaya (Singapore) every is an encouraging sign, especially ufford the Amateur Wireless So-less Society of Malaya (Singapore) assistance, and will be able to ro

so doing, you will remove, any do is to insert the primary winding possibility of saturation occurring of the transformer in series between ed, is because the additional valve and, moreover, the compartively low H.T. positive and the undode of has been connected

up in

an hap-magdiGention given by such a valve the pentode valve. The loud hazard manner without the know-will reduce the possibility of LF. speaker is then connected across the Sign cycle ledge that with the greater ampli-troubles. It is never advisable to secondary terminals. K.ZI.B. 1,152 Beation then available, there is also get too much magnification per K.S.M.S.. 1,083

With a pentode one can get much a bigger likelihood of something stage, and although you may grudge greater power without the neues 345 Tokyo "J.O.A.K. 870 353 Hiroshima J.O.F.E 850

going wrong.

this slight loss of volume, you sity of using an extra low-frequency 355 Hong Kong Z.B.W. 846

should bear in mind that this is stage, but care must be taken to port further, in three months' time, 357.1 Bombay V.U.B.

B40 381 Sapporo

J.O.I.K. 330

If the set already includes a better than to have a very big casure an adequate H.T. supply as to the possibility of acceding to 366 Keijo

your request" J.D.D.K: 820 trapsformer stage, the second in-volume with distortion. A After all, However, if the H.T. supply is 370 Nagoya J.O.C.X. 810 370.4 Calcutta V.U.O. 809.0

strument should have a very low the lost of volume will be quite sufficient to work a super power 380 Kumamoto J.O.G.H... 790

valve, then it is quite good enough 300 Sondai J.O.H.K,

ratio, certainly not greater than 3 small, 770 305' Dairen

J.Q.A.K.

740 400 Osaka J.O.R.K. 750 C.M.B 73% K.Z.R.M. 825

410 Canton

480 Manila.

SHORT-WAVE STATIONS.

STATION

CALL BION

Kro

TIME (HONG KONG)

OF WORKING

4,434 Man, Wed. & Fri, 6 pm & 2 am

67.66 Dobints (Germany)

A.F.K.

60.19 Khabarovsk (Rusia)

A97.

4,080 0-10 p.m.

69.7:

NERO...

A.G.J.

6,201 Not regular

30. Mosco

R.F.N.

6,000 Tace, Thurs., Sat., 8 pm.

13.6

Baine

Porth

MM.A 4.4.0.

6,898 Sunday midnight.

7,742 Daily 6.80 p.m. & 11 p.m.

47.9

Bingapore

7.8.1.AB.

P.C

38.8 Kootwijk (Holland).

27. Bangkok (Blam) HSPJ

Bydney

7,810 Not roguiar

7,780 Daily 11.p.m.

8,109 Tues. & Fri, 0 pm-1 am..

0,230 Not regular 0,503 Not regular s

W.LIAF. 9,680 | Dally 7

9,620 FYL 8 ain. Bat. 5 ́s,m, & 30's.m. 9,500, Not regular

2.BL.

31.66 Melbourne

8.1.0

81.48 Schemostady

51.20 Eindhoven (Holland)

P.C.J.

$1.29 Sydney

2.F.C.

81

Nairobi (Kenya)

7.1.0.

1,677 Midnight daily

29,6 Bydney

2.E.

10,820 Not regular

27.8 Bandoeng

P.LR.

26.59 Chelmsford (England) 5.8.W.

11,020 Midnight-8 m. dally 11,761 7.80 p., am. daily, except

Saturday and Sunday ELIT. 12.210

Nightly 11,850 m. ed., Fri., Bat, 10,102 Daily 6.80 pm, to midnight.

10,304 Dally 7 pm.

17,280 Daily 8 p.m. to midnight

24.0

Manila

28.35 Bahenectady

W.2.X.O.

18,89 Bandoong

PLG.

18.4

Kootwijk (Holland)

·P.CL

17.4 Bandoong

P.LF.

16.9

Bangkok

8.1.P.J.

17,751

16.0

Kootwijk (Holland)

POK

16.74 Bandoong

P.LE

16.5

Nanoy (nos)

10,251

Dally 8.

1983 Fittaburg

W.8.I.K.

21,640

Not regular

Bundays 7 p., & midnight" 18,404 ). Each afternoon --- 10,220 Dally 807 p.

** [Allowance must be made for "guramentims ? in moet Euro- pean countries, which is one hour ahead of trus tims.

Inserting De-coupling Device,

to 1. Moreover, it is just as well

Now in the ease of the last valve, for pentode. With a pentodo it in to incorporate a volume control of you will need one of the super-desirable, to have a volume control.

WAVE LENGTH CHANGES.

PROBLEMS OF AIR CONGESTION

Important changes in the existing wave-lengths of the broadcasting stations in England and do the Con tinent may be one of the results of a conference which is sitting at Copenhagen.`

ליי .

projetted programmes of more high-two years of communal listening, power stations, have made the and the use of wireless exchanges. question of broadcasting and wave It has an important political side, Jengths more dificați than ever bear the Left Wings of the Labour fores

parties are becoming increasingly There are, beyond the rapid conscious of the importance of the development of the high-power radio as a means of disseminating stations which are recognised by propaganda, a vlad the International Radio-Telegraphia Class consciousness by the Convention, other stations of equal. Communist section of European ly high power, which may "jump" Labour parties has been greatly a wave-length already allocated to helped by the steps taken in Russia, a member of the Convention. ** where redevelopment of com

For instance, a new high-power munal listening is an integral part station has lately been built by n of the Five Year Plan." It în syndicate in Luxembourg, which ob- proposed to establish 120,000 com viously is not intended simply to i munal listening-in village pointą in This is the meeting of the Inter serve the inhabitant of that small, connection with the Plan, Pa national Consultation Technical Duchy. What wavelength will it How communal listening is ex- Committee, who are engaged in fuso!

tending is shown by the fact that putting forward suggestions for 20" "The World's Lilteneri.~~.

Fin Holland 45 per cent of the the agenda for the International

listeners are on wireless exchanges, Radio-Telegraphic. Convention to be. It is catimated that there are over But: wireless does not recognisó. held in Madrid next year..

one hundred million people in the boundaries, and tho, individus pro- The conference is settling, among world listening-in every night. This grammes on wireless exchanges are other problems, one of the most im-number, however, does not include already, causing problems in our ́portant factors in the immediate | Russia, fors which the Sgures are rounding countries, and

future of broadcasting-the, distri: uncertain. In Europe, Denmark These are a fow of the problems, bution of warp-lengths for broad-, heads. the list of listeners, the pro- | which the Convention are notting caating purposes, especially in portion with sets of their own to out for settlement in Madrid next Europe, where the other gives every the total population, | last year, year. In is of-interest that of the sign of being congested in the near being 130,6 Sweden | second in six chosen representativos, who are future "Another important question Europe with 18:99—and Orest attending the Conventing on behalf is to decide whether the existing Britain third, with 77.4 per thon-¡ of the technical committed of the interval of nine kilo-cycles between sand set-owners,austro da quality International Broadcasting - Union. each wave-length sufficient. ( Another "problem" of political ax | two ars BB.C. engineers Mr. Nöel The increase in high power sta-well as radio-telegraphic importance Ashbridge, Chief Engineer at Savoy - tions in Europe, and the, further 1 is the great increase during the last | Hill and Mr. L. Hayas

Silver Marshall Superheterodyne

RADIO

t

wiren it is recalled that His Excel-. leney did much to promote wireless broadcasting in Hong Kong,

Engineering Features

Advanced 1932 Models

FOB

8-TUBE SUPERHETERODYNE

CHASSIS

(3-80REEN-GRID &

2-245 TUBEB)

TONE CONTROL LOCAL-DISTANCE SWITCH EXTENSION SPEAKER.JACK TEN K.O. SELECTIVITY SENSITIVITY-REDUCED

NOISE LEVEL ILLUMINATED DRUM DIAL FULL TONE ELECTRO-C

DINAMIO SPEAKED

NO REPEAT POINTS-

NO OSLLATION

CHASSIS ONLY 12

COMPACT SIZE

FOR FURTHER PARTICULARA, APPRX 70-,

THE WING ON CO., LTD.

„DISTRIBUTORS;