1931-06-04 — Page 2

HONG KONG DAILY PRESS, THURSDAY, JUNE 4, 1931.

RADIO

Hear the Golden Voice

FROM THE NEW

FEATURES

AVOIDING SHOCKS AND SHORT- CIRCUITS.

SOME PRACTICAL HINTS FOR BEGINNERS.

"Is there any danger attached to the working of a sot? Is it po sible to get shocks; is there any

quite safe to work from the ecc tric light 1"

but

ply' is switched off and, no other circuit is provided, there is the danger that, if the hands are placed

adjustment to the circuit, a shock may be felt if the condenser ter minals are touched,

TELEVISION IN SIX COLOURS:

AMERICAN SCIENTIST "MAKES IT POSSIBLE.

New York. Television pictures in different colours are now .com sidered possible by research work

RADIO DANGER,

Thermionic valves are usually fin ished off in an induction fur- nace, which is simply the space inside a coil; carrying a high-fro- quency current As soon as the valyo is placed in position, the metal electrodes are raised to ea

ATWATER KENT RADIO || danger front lightning, and is is bare peatoisote of ontdoor wires inside, the cabinet, to make some to the reddish orange siade of the some distanos sway, the inductive

our

E to

Radio COME

Department and let us demonstrate to you the new features of Atwater Kent Radio, Tone Control. Quick Vision Dial... Mastery of everything on the air. and many other vital points. that will interest you.

Listen to our Atwater Kent record. Hear how a great orchestra is build up--instrument by instrument---until all parts are blended into Victor Herbert's March of the Toys." You will enjoy this treat and feel marvellous. Come in! No obligation.

Decide for Yourself about Tone

The troubit is hardly ever likely to occur with indoor aorints and certainly not with frame aerials,

should make a point of fitting a safety spark gap, or, better still, an aerial-oarth switch, as close to the lead-in as possible. This may "efficient protection against big lightning discharges, but it certainly will prevent the set from being harmed by static discharges.

да

This is often applienced with mains units, the condensers of which generally have a very large capacity and hold sufficient elec tricity to give quite a bright spark if directly short-circuited within a few minutes after switching off the power. No harm will be done to the condensors by this short-circuit noling, but the shock experienced may

be considerable.

con-

These are the sort of, questions that every not owner has to ask himself when the aerial is over-not be hauled and one tentatively wonders whether there is any danger of lightning (the lightning danger is not confined only to summer time), or when a mains eliminater is, in-

The other "risks" iad not `are stalled and there is some. doubt

much more definitely under con as to whether there is any pos- trol; in fact with a carefully sibility of shocks or short-circuits.structed sot; there should be

Despite the millions of cutdoor possibility of shocks or short

This trouble can be minimised by aeria's which there aro in it is only circuits. If the sot works from infrequently one ever hears of a batteries, then all sorts of trouble making sure of cutting off the genuino case of an outdoor wire can be ebriated by the prevision high-tension supply before the fila being struck.by lightning, and then of a safety fuso A fuse of this ments are switched off. Most of the generally because that particular description should preferably be of condensors will then have an oppor serial was not carthed at the time the screw-in bulb type, for it gives unity of discharging through the and because there was no other ad- a visual indication when it "blows" filament anode pathe in the valves jacent metal. Direct "hits" by and fuses of this variety are chewIt does not follow that all the lightning are possible caly during per to buy and fit easily in stand fierce summor lightning storms. ard screw type buib sockets..

There is an atmospheric danger which exists all the year round,

The best place for a fuse in however, and it is quite likely to battery set is in the negative high- be serious during heavy rains, tensiun.connection. A siraile fuse Rain is frequently charged with

may be tied in a mainse electricity, and many users of sets, and it is also advisable tu Vide having an air dielectric preset fuse on the mains input side condenser in the aerial: load, find These can be of a different type that when rain is falling on the and it is necessary to have one fuss

THE SINCERE CO., LTD. aerial, small sparks jump across

SOLE DISTRIBUTORS.

The

the condenser insulation.

Statle Charges.."

These sparks are the result of the charging up of the aerial from the static potential of the anindrops. This potential builds up slowly until the value is so

Where to Place a Fuse.

ket

condensers will be discharged in this way, and if you want to carry out any adjustment to the set in perfect safety, you should first having switched off the bigh and denger in turn with a length of low tension-short circuit each era

flex.

white heat by the inductive action of the HE, ourrent, acting scross, To overcome paisible objections the intervening space. Even at neon lamp, Dr. Iloyd P. Garner, antion of radio-frequency energy of the Westora Television labora-can be quite pronounced, and more tories, has been experimenting with than one case is on record of den: cases which give various colours.tructive fires being caused in this The neon lamp, which comparea way. The United States Govern- with the diaphragm of the loud- ment have. in fact, recently pro- speaker in sound wireless, is used hibited the erection of short-wave in television to reproduce electric wireless transmitters near to any curront as lights and shadows

aircraft-fuelling.

the depot, on "ground that there is serious risk of explosion when petrol is stored in the vicinity.

How it is Done.

Dr. Ganner explained that he has been able to get pictures in yellow, red, blue, brown, sepia, green, or combinations of theso" colours. When a different colour was desired, he said, a different television lamp was placed in the

receiver."

...

He pointed cut that this "colour?- television was, not to be confused. with television in natural colours, which requires elaborat transmit ting and receiving equipment. The television receiver designed for broad tuning; is no more difficult to handle than the broadcast set.

Although still undergoing i

refinements here and there, it can "touching up" process of minor

Le built with single control tun

atus, there is a chance that a wrong gulate volume, or rather, inten With home marie mains apparing and an additional kach to re- onnection on the earth side will ity, for in televison advancing the

creasing picture detail.

in cack mains lead so that no mat. I causo a short-circuit. "An incorrect volume knob" has the effect of in-1

ter which wire is above earth, the | receiver is dequately protected.

Both with battery and mains driven sets there is the possibility

connection in the unit itself is easy

to trace, but it is not always no easy to trace the external maina wiring. This potential-danger-is

of getting shocks if the working of greater with direct current supplies the anode creuits is not properly than with alternating-current tealised. In the average set, there

A LITTLE

care in setting up an advertisement often doubles selling power,

It is that little extra thought and care, which is to every given advertisement drawn up in the- office of the Hong Kong Daily Press, which brings good results.

great that the current jumps the are at least two condensers which mains. Some dircut current wiring HAVE YOU HEARD THESE?

small air gap of the aerial conden £21. If a "safety valve" is not provided, the insulation of the tuning-side of the set may be damaged. It is believed that these static discharges are often the

have the full mains voltage across them.

If these have a value exceeding 1 mfd, then they will be found capablo-if the insulation is good

of holding an appreciable amount

systems have the negative wire connected to earth and some have the positive wire connected to Learth.

If these little points are watched,

EVERYTHING (GE.C. ELECTRICAL cause of cracked aerial insulators of electricity for perhaps several then there need never be any fear.

yout Zustander

COSIER FIRES

FOR COSY HOMES

ELECTRIC

Magnet

·An example from the -complete range of Magde Household Electric Appliances Irons Kettles.Toesten Ceaners Fans Fires Washing Machines Cookers Crillers. Appliances For the 'Toilet etc.

FIRES

MADE IN ENGLAND

THE GENERAL ELECTRIC COʻLTD"

Magnet

Fire

Current consumption z or si' unius an hour. Finished in brown, bine, green, grey or white vitreous enamel.

and broken lead in tubes..

ARMCHAIR ACTORS.

minutes. Thus, if the mains sup- of radio "riske,”

5.0,5, CALLS.

A REMEDY FOR FADING.

Radio actors appear to be in for

Between 860 and 950 S.O.S. colis,

Fluctuations in signal strength

a very easy time if the B.B.C. copies including police messages,

are due to fading are minimised in.

a new Continental idea. In a play broadcast by the B.B.C. annually commercial long-distance signalling recently transmitted from Lile, two

ü

of the principal parts were broad. It may be interesting to note that by what is termed automatic gaiz cast by the actors from their own of mesenges calling relatives to the control," in which the rectified out- sitting-rooms. By following the bedside of persons seriously ill, just put from the detector valve is used play with phones every member of the east was able to take his "Cues over half, are successful. Of mesto regulate the grid-bias on the first just as promptly as if all the actors Bages radiated at the request of the had been together in the studio. police for witnessee of accidopts,

A THIRSTY TRANSMITTER.

A modern broadcasting station consumes over 10,000 gallons of water daily for valve cooling pur poses. At Moorside Edge, provision has been made whereby no less than 200,000 gallons of water can be stor ed. When there's a droughton, things can become serious at a broadcasting station 1.

OPTIMISM IN CZECHO, SLOVAKIA-|

just under half are successful, On the other hand, only a fifth of the calls broadcast with object of tracing missing persons attain their object. Of every five 8.0.9. mes sages submitted to the B.B.C. for Uroadcasting only one reaches the microphone.

-5.0.5.

‹

H.F. amplifier, so that, as the sign-

strength falls off, the H.F. valva

is automatically made more "sen-

sitive" apd vice versa. The iden of compensating for fading has re- coatly been incorporated in Ameri can broadcast receivers, and will no doubt find its way, over here,

Fading control is

distinguished from ordinary volume-control by the fact that it operates solely to maintain the input or carrier wave at a constant strengh. It does not

Over a thousand ships are now fitted with special calling appara-affect the degree of madulation, so tus" designed to sound an automa that the relative loudness of differ tie alarm should the wireless opora- ont massages in a given transmission

The Czechoslovak radio authorities seem determined to please listeners, and they have copied the idea first. tried out in Denmark. They have or be off duty when the 6.0.5. is left unaltered, so long as the just issued a form which is to be signal is sent out from a ship in carrier wave is boing received, filled up by radio listeners. Ques distress. This ensures that no, call tions are to be answered regarding for help can go unanswered so long the popularity of each type of any ship equipped with an broadcast. It is not compulsory, ns-automatio alarm is within wireless

(Continued at foot of next column y ceding the netuZI ip' Denmark.

range. The devico is operated by

arbe

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 set sultable for re- ceiving such signals. Success in picking up these stations also depends very largely upon far- 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,

LONG-WAVE STATIONS.

Ware length

(Metres) Station

260 Manila

Call: Kin Sign cycle K.Z.I.B. 1,163 K.S.M.S. 1,083

277. Shanghai

345 Tokyo "J.O.A.K 870. 233 Hiroshima J.O.F.K. 880 385 Hong Kong Z.B.W, 387.1 Bombay V.U.B.

381 Sapporo

·366. Keijo

370 Nagoya 370.4 Calcutta.

J.0.1K

J.O.D.K. 820 3.0.0.K. 810 V.U.C 209,0

380 Kumamoto J.O.G.K.

300 Sendai

395 Dairen

400 Osaka

410 Canton 480 Manila

SHORT-WAVE STATIONS.

STATION

CALL BION

67.85 Dobints (Germany) 60.12 Khabarovak (Rusia)

Bome

587 ಕ. 43.5

413 .88.8

Nauenw Mosco

Forth

Bingapore

87..

Kootwijk (Holland). Bangkok (Siam)

Sydney

22.0

31.60 Melbourne 8148 Schenectady 3120 Eindhoven (Holland). 81.28 Sydney 81 Nairobi (Kenya) 23.6 Sydney. 97.8 Handceng

A.F.K.

B.A.ST.

A.G.J.

BEN.

TA

·

KILO

CYCLES

4,484

J.O.H.K. TID J.Q.A.K. 760'

C.M.B. K.Z.R.M. 693

Tims (Kone Kora)

OF WORKING

Mon, Wed, & Fr., 6pm, & am 4,000 610 p.m.

5,291, Not regular;

8,000 Tac, Thurs, Sat., 8 pm.

8,808 Sanday zuidnight 7,142

Dally &.80 p.m. & 11 p.m. 1,310 Not regular

1,780 Dally il p..

8,108 Tues, & Fri, 9 pm am.

8.A.G V.S.I.A.B. P.C.L. HS4.P.J. ARLA

9.280 Not

Not regular a.LOX

9,508 Not W.2.X.A.F. 9,550 Dally 7am. Not regular P.C.J. 0,680 Tri 8 Bal. 3. & 10 LF.C. 0,500 Nos regular 7.1.0.0,877 Midnight dally

Not regular

KIXE. 19,240 Wax.

26.08 Chelmsford (England) 5.8.W.,

Manila 245 23,35 Bohenectady

Bandoeng 18.4 Kootwijk (Holland)

18.88

Bandca

10.9 Bangkok 103

Kootwijk (Holland). 16.74 Bandoeng $13.5 Nancy (France)

13.93 Pittsburg

PLAG

PO

Midnight 8 am, daily

&6 am: daily, except by Estarday and Bunday

13.240 Nightly 12,850 Cam Wed, Frl, Bat. 16,102 Dally 6.30, pan, to midnight 16,804 Dally 7p.abdula 17,230

18 p., to midnight! H8.1.J. 17,751 | Sundays 2 pim' & midnight TCK 18,405 Each afternoon",

19,220 Dally 6,807 p.m. 10,851 Daily 3.

Wax K-21540) Not regular

A

TAllowance must ba'

for

In mort Buro

countries-

ahead of tru