1931-11-19 — Page 2

Page

HONG KONG DAILY PRESS, THURSDAY, NOVEMBER 19, 1931.

RADIO

EVERYTHING GE.C.) ELECTRICAL

your guaranter

GECOPHONE ALL-ELECTRIC RADIO SETS

and

RADIO GRAMOPHONES SPEAK FOR THEMSELVES.

DEMONSTRATIONS DAILY

¡ from 11.00 am.

All apparatus to the value of £5 or over can be supplied on hire purchase

terms.

Free service-for-3-months-

G.E.C. SHOWROOM Queen's Building, Chater Road, Hong Kong.

Osram

Valves

for

PURITY OF TONE

ARCTURUS

ACTION

in

SECONDS

Test Them Faster Bakter.

Tubea-To-dow

A-C LONG LIFE TUBES

ANGSLAUS

PZ- PENTODE

See the New Products

TYPE 551 VARIABLE-MU TUBE

New in design Advanced in principle Efficient in

performance.

TYPE PZ PENTODE

Higher power sensitivity Greater mutual conductance Larger undistorted

power output.

THE TUBES WITH THE

LIFE-LIKE TONE

For Better Results, Use" Arcturus" Blue Tubes.

THE SINCERE Co., LTD.

SOLE AGENTS.

FEATURES

WIRELESS FOR THE

SMALL SHIP.

ECONOMIES THAT CAN BE EFFECTED BY ITS USE,

So much has been written about the elaborate wireless installations now carried by large passenger ships that the usefulness of wiralens

to the small cargo ship is apt to ba overlooked. Apart from its safety of like considerations, wire- less can be just as valuable to the small ship as to the large one in safeguarding "hull and cargo, keep ing the ship up to time, and in many aspects of organisation and trading.

Every British ship of 1,500 gross tons and upwards is compelled to carry wireless apparatus with cer- tain minimum requirements, but

ita usefulness 19 нo marked that it

is exceptional to find a ship's wire-

less installation that does not ex-

ceed this minimum.. It is just as exceptional to find a shipowner who, once he has experienced the

}

many.

advantages of installing wire less on his ships, would be without it even if the law allowed the omis

|

DO YOU KNOW?

من

that some sats which motor-boat when a speaker output transformer is used may not do so when after circuit is used? This is particular ly the case with arts having an ultra-compact layout and is worth doting, especially when large power valves and heavy-duty speakers are... employed.

heard of again. It may, of courie, have met with disaster which over- whelmed suddenly and which would have prevented the use of wireless if it had been carried, but, on the other hand, there may have been just a few brief minutes avail- able"in which a hurried call would have brought help. Such cases aro exceptional, it is true, but the fact that they do happen provider a powerful exhortation to owzers to take full advantage of the facilities unde available by wireless.

DISTANCE

GETTING.

AND HOW TO DO IT.

For some obscure reason there are distant-station reception that is several mains valves which make worth listening to if there is tob good detectors and which do not much extraneous noise, y appear to be so critical in the

Sometimes

poor earth used, with mhtter of circuita condition as are mains-driven ct will upset the If you cannot get a satisfactory battery valves. In some maina number of foreign stations-885; Mullard 384V, and the Marconi or increase the amount of ham File driven sets, the Mazda AC/HE, the tuning pad, reaction and will also twenty or thirty-on a set which is Osram MHL4 give good reanits.ment wiring, too, needs to be car- guaranteed to receive them, then There are many other mains valves ried out carefully if the A.C. there are several possible causes,

which also function very well in ripple is to be cut out. It is a the detector stage and give no re Slow tuning and proper use of action bothers

good plan always to twist together the reaction control are the two

The only trouble with bome the Alnment loads in &- mains- quickest ways of getting plenty of maina-fod detectors is that there driven sot in fact it is easy to may be a slight background of A.C. | wire up this part of the circuit with bum and, of course, you can'i; get. [. ordinary maíns flex”

stations..

Control of reaction le equally im- pertant. You must realise that

control cannot be left in one post with the average set the reaction

tion, so that the set is on the verge of oscillation, and searching then effected with the main tuning 'con-- trol. With straightforward circuits | the oscillation point is not usually the same all, over the tuning dial.

Practice at the Dials.

T

It may take an hour or so at the time to get accustomed to the work- ing of the reaction control.in con- Another incident is provided by junction with the tuning knob; but a ship of 300 tona which ran this practice is worth while." If ashore during & voyage between your set has only one high-fre two Continental ports. The forequency stage, or perhaps no valve part filled with water and cargo at all preceding the detector, then was discharged into lighters. There it is only by the proper use of rét are many expenses involved in such action that you will get foreign sta

case-salvage discharge and re- tions. shipping cargo, repairs, docking, ete.--in addition to which the owner loses the use of the ship for some time while she is being repaired. Could wireless have prevented the It is surprising, therefore, that stranding? It is more than likely that it could, especially if the ship owners of ships below the tonnage had carried a wireless Direction which maken wireless compulsory.Finder." This, therefore, is a strong including those engaged in the argument why, this instrument should hid a place on every ship, home trade, have not taken greater

whatever its size, as it is the only advantage of the small installations reliable means of determining the which are now available-and which ship's position, no matter what the provide communication up to dis state of the weather may be.

tances of about 300 miles-to t

sion.

their ships with wireless, Many of these could profitably carry wire-

less, the two principal reasons why these installations should appeal to them being the economic and the humaae benefits which would re-

sult.

14

HAVE YOU HEARD THESE?

Here, ara- lists of long-w&TI and short-wave station which should be picked up by anyone in Hong Kong who has a mode- " | rately good set suitable for re- --belving, such signals. Success in picking up these stations also depends very largely upon far- curable atmospheris 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:

||

LONG-WAVE STATIONS.

WATE length

(Matros). Station

260 Manila

Call :: Bign

...Kilo

cycle

K.ZLB. 1,158 K.S.M. S. 1,093 J.OLA.E. 870

277 Shanghai 345 Tokyo 383 Hiroshima J.OF.K. 850

810- 355 Hong Kong Z.B.W YUB 357.1 Bombay

„240, 301 Sapporo J.O.I.E. 830 J.O.D.K.. 800 J.O.C.H. 610 V.U.C. 800.9

366 Keijo 370 Nagoya 370.4 Caloutta

380 Kumamoto" J.O.G.E.

300 Sendai

395 Dairen

400 Osaka

410. Canton,

480 Manila

SHORT-WAVE STATIONS.

STATION

CALL SIGN

Perhaps you find that there is reaction overlap, or that the set of oscillation. These are fatal to dues nct slide smoothly in and out good reception. You must remem ber that if the reaction cannot be applied gradually and smoothly

87.88 Dobintz (Germany) brought to its most sensitive con- 68.7 then the detector valve cannot be 60.12 Khabarovsk (Russia)97.

to oscillate. dition, that is, just before it starts 43.6

50.

4.F.K.

Nanow

A.G.J..

Mosco

REN.

Bome

.M.A.

42.

Portia

6.A.G.

41.8

Singapore

V.8.1.A.B.

38.8

Kootwijk (Holland)

| P.C.L.

Bangkok (Ulam)

Sydney

37.

81.

You can make quite a simple test to discover if your present re- 82. netion is good or bad. Switch on

81.56 Melbourne the set and tune it so that no sta

31.48 Bobenootudy These incidents show that wire-

81.20 Eindhovon (Holland) tion is received, Gradually in- 81.28 Sydney auxiliary equipment which ships of the reading on the dial. Turn the 27.5 Iras is not merely a pices of

Nairobi (Kenya). crease reaction and note carefully 28.6 Sydney over 1,000 tons carry only beegusdial a little further so that the set they are legally compelled to do is well oscillating and then slowly so, but that it is an important part turn the dial back again. 77 oscil 18.95 Bandoang, of a ship's equipment which no shipowner can afford to be without, whatever the law may say in the

matter and however smail the trad ing ship concerned may be.

where it hegen, then there is some- lation does not stop at the point thing wrong with your reaction

arrangements.

Economic Advantages. From the economie point of view, an important consideration is that wireless provides the only way of maintaining contact with a ship at Beh. If full use is made of it, un medical advice, and such matters necessary expenses in connection of vital importance to the welfare with pilotage, docking, reservation and contentment of its personnel. This is a double advantage as it of berths, cargo working, etc., can gives ship' crows the satisfaction

It is difficult, of course, to givo; he avoided, especially if the ship is that they are well care for if eir-

general advice which will apply to delayed, and the saving brought cumstances makes it necessary to

(every type of ́sot. If your detector valve is of some type, auch as the about by the ability to communi ask, for help, pad also, it places Mullard PM2DX, Corsor 10DET, them in the position of being ableMarconi or Osram Le10, or the to help others.

Assuming that. the set is made The Enmane Aspect.

up according to a standard circuit From the humane point of view and that proper values of com very little need be suid. Wireless ponents are used, then it is safe to provides every ship carrying it with any that the reaction fault can be a means of calling for assistance.traced to an unsuitable detector

cate with a ship at any time in regard to these matters soon pays for the wireless installation.

Direction Finders for Navigation,

It is perhaps not. generally realis- ed that even when a complete wire- less telegraph installation is not considered necessary

wireless Direction Finder can be carried for navigational purposes without other]. equipment, and that the ship'a officere can soon become aecom-

plished in its use. The latest types. of this apparatus are very compart and can easily be installed in small ships, in fact a large number are already carried by trawlers and yachts.

Where Wireless Might Help.

Two recent incidents serve to illustrate the value of wireless - to' the small ship. In one case a ship of 1,100 tons left portland was vot (Cantinued on nezi Uolumn.)

A LITTLE

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

It is that little extra thought and care, which

is

given to every advertisement drawn up in the office of the Hong Kong Daily Press, which brings good results.

ave, to an incorrect highrtension Falue, or to badly-chosen values for the grid condenser and leak.

Mazda L210, then you may find that best results are obtained with) a voltage in the neighbourhood of 100 and with grid condenser and leak values of .6002 microfarad and 2 megohms, respectively. This as- sumes that the detector stage is followed by a standard-ratio LF transformer.

For Special Sets,

If a transfermer is used having

a special ratio and, therefore, a | particular

primary inductance value, or even if the detector ·is) followed by a resistance-coupled stage, then obviously another H.T. value will be called for, With certain types of detector 45 to 60 volts are required on the anode and with a slightly higher value of grid leak, up to 5 megohms.

It is generally possible to borrow one or two grid leaks having dif ferent values and to try each in turn, altering, the amount of B.T. applied to the detector tapping..

HS4PJ.

1.B.L.

3.LO.

W.2.X.A.F.

P.C.J.

2.F.C.

7.10.

Bandoong

2.M.E. PLR 25.53 Chelmsford (England)] 5.5, W.

24.5 Manila 20.35 Schenectady

<

WIXO.

P.LG.

[R,QL/

P.LF.

E.8.1. P.J.

P.C.X.

P.LE.

WA.XX.

18.4. Kootwijk (Holland) 17.4 Bandoong 16.0 Bangkok 18.8

Kootwijk (Holland): 15.74 Bandoeag 15,8: Nancy (France) 18.93 Pittsburg

Kito

CYCLES

790

J.0.H.K. 770 JQ.A.K. 700 J.O.B.K. 780 CM.B. 789 K.Z.R.M. 095

TIME (HONG Kozo) OF WORKING

4,434 Mou., Wed. & Fri., 8 p. & 2.m 4,900 8-10 p

8,201 Not regular

6,000. Tue, Thuri, Sat., 8 p.m.

"6,806 Sunday midnight'

7,142 Daily 6.80 p.m. & 11 pm.

7,810 Not regular

7,780 Daily 1 pm.

6,108 Tues. & Fri., 8 p.m.-1 a.m. 9,280 Not regular

0,508 Not

regular

9,880 Daily 7 a,m,

0,020 | Fri 3 Am., Sat. 3 a.m, & 10 r.m.

2,500 Not regular

9.077 Midnight daily..

10,628 Not regular

11.00 Midnight-8 m. daily

11,761 7.80 p.m. & a .m. daily, except

Saturday and Sunday

12,240 Nightly

12,850a.m. Wed., Fri, Sat.

10,102 Daily 0.80 p.m. toʻmidnight 20,804 Daily pu

17.280 Daily 8 pm to midnight 17,761 Sundays p.m. & midnight 19,404 Ench afternoon.

19,220 Daily 30 p.m. 19,861 Daily Bam.

21.64 Not regular

[Allowance must be made for "summer-time” in- most-Furo- pasa countries, which is one hour ahead of trus time.]

Ideal for XMAS GIFTS. PILOT A.C. Midget Superheterodyne

(Lowest Price Ever Offered.)

Skilled Radlo Experts Supervision

Free Service to Patrons

1982 Model Engineering Features

7-Tube Superhet. Circuit (Including Multi-Mu Screen Grid and Power Pentode Tubes.)

Hair Line Selectivity

Volume and Tone Controls

Local-Distance. Switch

Pick-up Connection

Moving Coll Speaker

THE WING ON CO LTD.

TEL. 26871,

Sole Distributors.

Tux, 26672.