1932-01-28 — Page 2

Page

HONG KONG DAILY PRESS, THURSDAY, JANUARY 28, 1932.

The

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1

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FEATURES

WHAT 1931 GAVE US AND

HOW ABOUT 1932?

PEEP AT LIFE- IN 1950.

SIR HUGH ALLEN PICTURES

THE B.B.C."AGE,

SWITCHES AND BUTTONS.

Wireless is still at the stage where A rough-and-rendy method of each successive year produces some accuring much the same result is development or other which tends to fix the tuning of the primary to make inst year's practice look acireuit at, say, 600 mttres when the A bit old-fashioned. This may, per

haps, be a drawback from certain points of view; but, on the whole it is a sure sign of healthy progress. From a broad point of view, laat year seems to be marked out by in tensive developments in the use of the scale the fixed primary gets London recently. He said:-

high-frequency amplification.

switch is on the 200-860-metre side. Then as the secondary is tuned to" any desired station, the "natural tendency to increased amplification on the shorter waves is again offset by the fact that as one moves down

more and more off tune," and so

A picture of the future life of a citizen provided for by the B.B.C. was drawn by Sir Hugh Allen, director of the Royal College of Music, at the conference of the In corporated Society of Musicians in

"Ons might say that the age of

The ether was never so crowded serves to cut down excessive eners the human race is roughly divided.. into three parta The old ago is

with good things as it is now, but

on a short-wave setting, and pro-

it has never before been so difficult vent any tendency to oscillate that known as B.C., the more modern as |

to pick and choose between them,

might otherwise arise.

Variable-mu Valves..

A.D., and the future age is going to be known as B.B.C.

The response of the designers to this problem of selectivity has been to develop new ways, and means of',

The appearance last year of a

"I want you to realise for a improving the high-frequency side new typo of valve, with very un-moment what will be the life of a of the receiver. Here they have usual properties, maaks an event person in 1850 lying in Led in the peen helped enormously by the of far-reaching importance. The morning in a room surrounded by introduction of new valves of ex. ordinary S.G, amplifier has a high an enormous apparatus covered ceptional power and efficiency with amplification factor-in some cases with switches and buttons and

various other things amplification factors measured by, as high as 1,500-which keeps con- the thousands instead of in tens of start within fairly narrow limits. The result is that it becomes difficult hundreds,

to keep the loud-speaker volume within bounds when one changes over, say, from a distant station to the local transmitter.

羶

Band-pass Tuning.

༈་

Morning Signals.

HAVE YOU HEARD THESE?

Here are lists of long-waAVÈ and short-wave stations which should be picked up by anyone in Hong Kong who has a mode. rately, good sot suitable for ro- ceiving much signals, Sucoses in picking up these stations also depende very largely upon fav. ourabls 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.

A

LONG-WAVE STATIONS.

Wave length

2.Uzale

OKII Kilo (Motres) Station Sign

250 Manila.

EZ.I.B. 1,19 277 Shanghai K.S.M.S. 1,083 345 Tokyo "J.O.A.K. 870 353 Hiroshima J.O.F.K. 850 355 Hong Kong Z.B.W. 840 367.1 Bombay V.U.B. 840 J.O.LK. 830 368. Keijo " F.O.DK..

J.O.U.K. 370 Nagoya

810 V.U.C. 370.4 Calouste

800. 380 Kumamoto J.O.G.K. 790

381 Sapporo

390 Bendai

395 Dairen

400 Oska

410 Canton 480 Manila

SHORT WAVE STATIONS.

STATION

CALL. SION

87.65 Dobinti (Germany) A.F.X. 60,12 Khabarovsk (Bunkin) (.497. 30.7 Nanan

A.G.J.

50%

Mosco

REN..

40.5

Rome

LMA.

Perth

41.3

V.S.1.A.B.

"At eight o'clock there comes a signed, and it says: This is the 25.8 British Bath Companyy

We urg taking you over to the company for the Kid-Regional After that we touch another button programme.' and we have our breakfast by the

British Breakfast Company....

the

With plenty of power in hand, it is possible to use selective circuits

In the new variable-my valve th: af, rather more complexity than usual-e.g., band-pass tuning-see-amplification varies in an elastic ing that any resulting loss of manner, so that the valve amplifies energy can always be made good, enormously on weak signals from a

Again we touch a button and For the same reason, "reaction has distant station, but comparatively.

go by the British Bus Company.' gone completely out of fashion. little on the much stronger inputs We live in lodgings provided by most modern receivers are of the from "a station at close range. soraight-circuit type, with a ghain Some slight alterations are necesWe are born by the British Birth British Boarding Company:' of inductances and capacities formsury before the new valve can Be ing a hand-pass input to the first fitted to standard set, go as to valve. In some casey a similar filter chsure that variation of the control circuit is used to couple the H.F.grid bias does not upset fixed 8.0. stages together.

voltage, but these are not dificult to carry out, and the result advan taga of easy volume control is well worth while

:

1]

Singapore Kootwijk (Holland)

·Bangkok (Slo) Sydney

6A.G

KILO

3.0.H.K. 770 J.Q.A.K. 760 J.O.B.K 760

C.M.B.

739 KIZ.R.M. 025

P.C.L...

ILS.APJ.

Tin (Hong Kono) OF WORKING

4,434 Mon.. Wed. & Fri, 6 p., & 2 am 4,990 6-10 p..

5,291 Not regular-

8,000 Tue, Thurs., Sat., 8 po

6,890 Sunday midnight

7,1-42 | Daily 6.30 p.m. & 11 p.in. 3° 7,310 Not regular

3,730

Daily 11 p.m.

8,108 Tuos, & Fri, 9 p.m.-1..

0,230 Not regular

9,603 Not regular

W.Z.X.A.F. 9,630 Daily 7 a.m.

Fri. 3 a.m., Sat. 3 am, à 10 alm. 9,600 Not regular

9,677 Midnight daily

10,026

Not regular

| 11,420 | Midnight-3 aim. daily

11,751 7.80 p.m. & 2 a.m, daily, except

Satu day and Sunday 12,240

+

18,850 4. a.m. Wed., Fri, Sat. 16,102 Dally 0.80 p.m. to midnight

37. 32.4

f

8265 Malbourne 21.48 Schenectady

1.B.L... 2.1.0.

31.20 Eindhoven (Hclinud) 31.28. Sydney

| PC.,

2.FC.

Nairobi (Konyn)

7.1.0.

28.0 27.8 36.58

Bydney

X.M.E

Bandoong

P.L. B

helmeford (England)

5.8 W.

K.1.X.B

28.85 Babonectady"

15.88 Rnudoeng

W.2.x.0. F.L.G.

18.4

·P.C

18.004 Daily 7 p..

17.4

P.L.F FI.B.1.P.

(17,280 | Daily 8 p.m. to midnight

17.751 Sundays 7 pm & midnight

P.C.K.

P.LE.

19,220 Dally 5.30-7 p..

19,351 Dally 3 ..

W.8.X.K.

21,540 Not regular

24.5 Manila

Kootwijk (Holland) Blandong 18.9 Bangkok Control.' We are named by the 18 Kosbwijk (Holland)

-18,74 | Bandeeng British Baptism Company,' and

10,5 Nancy (Franco)

we are married under the Bride 13,93 Pittsburg and Bridegroom Convention. We│ are buried by the British Burial Company,' and that is the end of

life.

In the Picture Frames,

Nightly

18,504 Each afternoon.

[Allowance most be made for ** summer-time” în most Euro,

.... pasa countries, which is one hour ahead of true time.)

Think what it will be for artista THE DAILY ROUND IN clear. A few more who were in the when, in a new house built some years heneh, you haya no pictures re-only empty frames. You touch a

nu.

The use of the band or filler type of circuit to pre-select the desired signal is preferable to ordinary razor-edge tuning, because, it com- The new valve also makes it pos bines reasonable selectivity with sible to utilise automatic volume good quality. Razor-edge tuning control RO that ductuations of will certainly give all the selectivity strength due to fading will that can be desired, but it tends long irritate the listener when to overshoot the mark by cuttingceiving distant programmes. Thi the side-bands of the incoming problem can be solved by using signal so severely as to strip away ruch of its musical" quality.

A band-pass filter, on the other hand, admits both the earrier wavel and the side-bands of any desired station, though it excludes any in terfering station. That is to say, it will exclude any other station which keeps outside the -kilocycle spacing recommended by the Inter. national Broadcast Commission.

Unfortunately, the **

second rectißer valve to produce an automatic grid-bius voltage for the variable-mu. H.F. stages,

button and it produces a picture of Leonardo da Vinci, or you touch another and see the Sqricts in Moscow playing cricket.

A SUBMARINE.

(Continued from Page 1)

first lieutenant. The second cox- That is what is going to hapswain on the foremost planes puls If the signals are strong, the outpen, and it seems to me that will be gut from the regulating valve is a very dull life to live. It will be

on nome "Rise Helm." The cox- automatically increased so that an essentially, lazy one, and that is swain on the after planes puta on strong negative bias is immediately really at the root of all our dif. applied to the H.F. valves, teading ficulties."

to cut down their sensitivity. It signals are weak, the negative grid spacing bias is automatically lessened, and

is not always observed by the

different transmitters, in which case it is practically impossible to Provent overlap,

the HF. vaives at once respond

crew

control room rush up the conning

tower ladder. The men in the torpedo" compartment hear tha crash and see the rush of wawr: They slam the watertight doors dividing the wardroom and space from forward. Perhaps the men in the engine room du" the

same. Those who cannot get up the tower are, drowned at once by the rush of water or suffocated by the chlorine gas when the salt water The future," Sir Hugh said, undoubtedly holds some very ex-

rushes into the batteries. The men

citing, stimulating and enccessful

in the fore compartment now loos times We are living in strange

at one another and say, "What are times and at a great pace,

the bridge, followed by

the we going to do about this " "Weeks are now days and signalman. The air pressure wo Perhaps the torpedo gunner's. maio" month are weeks, and we cram into have used to blow our tanks bas, is there, a man with many years' these periods of one week all that

taken out just sufficient to put our explains to them that there is only experience in submarine work, He we used to get in a whole year.

41

Strange Times.

some "Dive Helm to make the boat rise bodily and not nose Arst, and up to the top we go.

"Stop blowing," ordere. the first, lieutenant. The captain opens the conning tower hatch and goes up

to

with, increased efficiency. In this way the loud speaker output is kept uniform under all conditions." Constant Amplification.

Better Detection." Another tuning problem on which considerable work has been done is that of that of maintaining a con-

The-warch-for a perfect rectifier stant degree of amplification at all naturally follows close on the im settings of the tuning dial. When-Provements made on the high-fre We fly through the country seeing conning tower and casing clear of one way. They have the new life

quency side of the sot. The old ever an ordinary tuned circuit in grid-loak rectifier is highly sensi. nothing, listen to music all day on the water. The captain now used either as an input to a valve,

gets saving apparatus.. or as an intervalve coupling, there live and fairly satisfactory-within the wireless hearing nothing, and inte communication with the tender! is a tendency to favour the shorter first-class quality is required, how

certain limits. Where absolutely we gradually go by geometrical pro- wavelengths as compared with the the inductance capacity ratio as one the tuned input circuit, (b) that no time to sort anything out, and out. If we are not going to make vojec pipe cock and letting in the long ones, owing to the change in ever, it is opan to objection, (a) on gression or proportion into a very and learns the result of his attack opened until the internal pressurs

can be remedied by opening, thes tunes down the scale.

The foremost hatch cannot be

the ground that it tends to damp strange state of things. There is The day's nation "of rum is served equals the external pressure. That

it works on a bent part of the

This tendency is well-known to characteristic curve. For both these there is no time for us to soak any another attack the air compressors, water. Flooding the compartment the designer, and in practice he reasons it is liable to produce dis. thing, in." generally compromises by deliberate tortion.

ly designing a dual-range set, so

wave side of the switch.

The anode-bead rectifier avoids

are put on to blow out the remain will compress the air until it lifts

der of the water. The amgston

the batch The men knock off ́all

the clips except one of the batch,

our torpedo. This is life-saving apparatus and wait.

only a foot or so of air in loft.

that it is just stable on the medium both these defects, but tends to dis-pull, the two ends of the input valves are olceed, and we praced open the voico pipe, put on their wavo setting, although he know tort on a highly modulated signal transformer being connected direct that this inevitably means a cer Power-grid rectification is to be ly (and not through a blocking conto pick up tain loss of sensitivity on the long-preferred to both, and is, in fact, densor) to the two grids.

Any such sacrifice can be avoided reproduction. Even here the pro- now generally used, for good-quality

The absence of the grid condenser lowered through the foremost hatch The water rises up and up until by the so-called constant-coupling sence of a grid condenser is, how: proventa any risk of damping or and placed on the checks ready for principle, where anergy is transfer-ever, still a source of weakness, na

distortion, whilst any H.F. prosent red from one circuit to another, it tends to cause damping.

is balanced out in the output of overhaul, partly by capacity · coupling and

the two valves, so that there is no The push-pull detector is the likelihood of its reaching the LF. partly by magnetic coupling. In mixed coupling of this type the latest arrival and is likely to be stages. The reotified signals add natural tendency of the condenser widely used in next year's sets. As together in the output circuit, ba to transfer more energy on the its name implies, it calls for the cause they are, in effent applied to shorter wavelengths and less on the use of two separate valves, instead the two grids in paralled across the longer is offset by the opposite ten of one, though there is no reason input transformer, which only offers dency of the inductive coupling why both should not be contained a high impedance to the carrier The two opposite effects counter in the samo glass bulb. The signals wave and low impedance to the balance so as to sursa constant to be rectified are applied in pushual frequencies. Amateur Fire transfer at all wavelengths. 1 (Continued at foot of next column.) lesa.

WHEN AN ACCIDENT HAPPENS.

The hatch clip is knocked off and v thenden shoot in a bubble to the surface. Perhaps some hit the edge of the hatch as they shoot through or the jumping wire But imagine what happened to stretched tout above them. But the Poseidon. A small steamer is some escape, thanks to the Davis quite close to u and we are hit-Apparatus and the experience of u before the tower. The captain and man who has always been ready fer the men on the bridge are thrown just such an emergency as this