1930-07-31 — Page 2

HONG KONG DAILY PRESS, THURSDAY, JULY 31, 1930..

RADIO

FEATURES

AIDS TO BETTER RECEPTION.

MAKING THE BEST USE OF MEASURING INSTRUMENTS.

The importance of a periodical overhaul of a receiver has previous ly been stressed in these columns, and for those who prefer to under- take this task themselves rather than entrust the set to a dealer the observation of a few simple points should prove helpful.

The first essential is, of course, one or two tools and instruments, Nothing elaborate is required, and for tools a 'light pair of wiring pliers, an istrument screw-driver, and a small soldering-iron will be

1)

[BY · COHERER."}

the same instrument will be found quite useful for tests of continuity.

Continuity Tests.

ter-

£15

Another point of equal import- An exceptionally good loud. ance is the plug-in connection, such speaker is now on the Hong Kong is used for valves and coils.market, ie, the Celestion Cone. These plugs are apt to became com- Reproduction of high and low notes pressed with continual use, so that is extremely good, and the price is It is well worth ask- connection may be made at only reasonable. one point on the surface of the ing the agents for a demonstration. socket. A careful, prising-open of the spring-legs of the plug until a tight connection is obtained will easure against such bad contact, and will get over a good deal of the "home-made". atmospheres caused by such defects.

current and voltage can be mea- sured "with one instrument, employ ing a double reading-scale, render- ing possible the measurement of

For this latter test a small bat- both high and low tension. When exploring the internal connections tery of 4 to 6 volts is required, of a large set for tests of continuity being connected between å

SOME USEFUL HINTS. the handling of such an instrument minal on the testing panel and one calls for considerable dexterity of the leads used for making con-

When buying a Mains Unit, make while endeavouring to make connection, On the two leads being

sure it complies in its construction nection and avoid short-circuiting connected a swing will, of course,

be registered on the meter, and in with the recommendations laid at the same time.

this way the whole set can be test-down by the Institute of Engineers ed out point by point from aeria) See that the unit chosen has ade to loud-speaker-no swing or an in-quate power output for the require

A Simple Test-Set.

For those who are of a construc-

*

For sensitivity's sake it is often an advantage to reduce the value of the short-wave condenser. 'to .0001, and increase the grid leak up to about 6 megohms.

A run-down HT. battery is the cause of sizzling noises accompanied by distortion.

most

commen

*

+

A strong solution of ordinary washing soda will completely' re- move deposits" upon accumulator terminals.

Before trying to find a fault, in &.

all that is necessary for the major-ive tura of mind, a very useful termittent movement of the needle ments of your set. It possible.receiver, always disconnect the bat-

י

ity of sets.

For the latter article. the elec trical type is recommended, being clean, convenient, and capable of retaining heat, though the actual copper portion may be quite small. With one of these tools, clean joints, and a good flux, soldering will be found a simple and even

test instrument can be made. from

indicating a. break or bad joint in one of these meters, a small piece the particular point under 'test.. of ebonite, a few terminals, and a For testing transformers or chokes short length of wire. The meter is

a pair of headphones, wired to mounted in the centre of the battery in the same way as the ebonite, and terminals, suitably meter just described, offers a better marked, are screwed at each end. indication of continuity of winding Connections are wired under the The high-resistance of these com- panel from terminals to their reponents would not allow a very spective points of the meter. A appreciable movement of the meter: light wooden frame-work to act as needle, while the "click". heard The Volt-Ammeter. With regard to instruments, all a support and a pair of long leads through a pair of headphones when that is required is a hydrometer, with metal connecting-points com connection to a hattery is com- for those using a battery-operated pléte a most useful addition to a pleted is most distinct. set, and an electrical measuring wireless installation. With it, both instrument.

voltage supply and current con-

congenial task.

A most useful combination of am-sumption at any point in the rc- mster and voltmeter is obtainable ceiver can be quite simply checked, locally, by means, of which both and also, when searching for faults,

EVERYTHING

The

G&C ELECTRICAL

your guarantee

TENACIOUS COATING

KEEPS YOUR SET

AT PEAK PERFORMANCE

"It's not the filament but the coating on it that counts

Osram

Valve

Overhauling...

bave the unit demonstrated on similar mains and with a similar set to those you will have to run A perfectly silent back ground should be aimed at.

it on.

speaker, and they ars joined in If you use more thas one loud-

pary on-off switch wired across the series, do not forget that an ordi-

loud-speaker terminals will enable the instrument to be eut in or out as desired.

In short-wave work the high- frequency choke is of paramount importance, so only a good quality component should be used.

The most important wires in a short-wave set-are those from the grid to the tuned circuit, the next in'importance being the plate leads.

teries.

The damping effect of a close- coupled aerial circuit is very much greater in a short-wave set than in the case of a set working on ordi nary wave-lengths.

TO-DAY'S WIRELESS

PROGRAMME.

'BROADCAST BY E.B.W. ON

355 METRES

11 to 11.30.-Cci.mercial News. 11.30 am to 12.30 p.m.-Chinese

prograianta,

12.30 to 1.30 p.m.-Mid-day pro

gramme of H.M.V. and Victor" records selected and supplied by

outrie & C

An important point to look for when overhauling a set is defective soldered joints. These are apt to get dry after a while if badly soldered in the first instance, and when such a defect does occur it is most difficult, to trace, giving continuity of circuit. while at theIt is generally the last or output.

valve that causes distortion, alto some time causing crackling when though other valves are occasion..

set is subject to vibration.

ally to blame,

the

#

HAVE YOU HEARD THESE?

Here are Hats of long-wave and short-wave stations which should be picked up by anyone in Hong Kong who has a mode- ratoly good set suitable for re- calving such signals. Success in picking up "these stations also" dependa very largely upon fav- ourable atmosphèric conditions.. Readers are invited to add to this list should they succeed in picking up any station not in- clüded in either of these Hists.

LONG-WAVE STATIONS.

Wave length

Call Kilo- (Metres) Station Sign eycle... 200 Manila K.ZI.B. 1,153 277 Shanghai K.S.M.S. 1,053 280 Tientsin. C.ILC. 1,070 210 Shangbai. E.R.C. 967 320 Peping

C.O.P.E." 143 343 Tokyo J.O.A.K. 670 353 Hiroshima J.O.F.K. $30, 355 Hong Kong Z.R.W. 846 357 Bombay V.U.B 361 Sapporo JOLE. 630 355 Keljo J.O.D.K 620 370 Nagoya J.O.C.K. 810 370.4 Calcutta V.U.C $09.0 360. Kumamoto J.O.G.K. 190 390 Sendai JO.H.K.

J.D.A.K

395 Dairen

810

.770 - 760

398 Rangoon . V.U.R. 754

400 Osaka

410 Canton

413 Manila

J.O.B.K. 750

*C.M.E. 739

K.Z.R.M. 726

1.30 p.m.-Weather report and local time. Mid-day European pre gramme continued.

2 p.m.-Close down.

6.30 to 8 p.lu-Evening European programmé of H.M.V. and Victor records selected and sup plied by loutrie & Co. "The Girl Friend," Selection.-

Savoy Orpheans.

Oh, Could I But Express In Song" and "Sincerity" Peter Dawson:Bass Baritoné.. **Ballet Egyptien." Reginald

Foort-Wurlitzer Organ.

!!!

"Ca men Suite"; Gypsy Dance. Intermezzo, Soldier Changing the Guard, and March of the Smugglers. Philadelphia

ด

Symphony Orchestra. "OfTo Philadelphia " and Chorus Gentlemen."-Percy Heming-Baritone.

"Tambourin

Thais,

Chinois" and Meditation-Fritz Kreisler-Violin Solo. Faust-Ballet Music": 1, Dance of the Nubians; 2, Cleopatra and the Golden Cup: 3, Dance Antique; 4, Dance of the Cleopatra and Her Slaves; 3, Dance of the Trojan Maidens; 6, Mirror Dance; and 7 Dance of the Phryne.-Royal Opera Orchestra, Covent Gar-

den.

"One Alone" and

Baker-Baritone.

It."-George

An Autumn. Serenade"

Poem." (Organ);

and

Reginald Foort

"Kiss Your Lips” and “Salut D'Amour." Marek Weber and His Orchestra.

T. C.

C.

FIXED CONDENSERS

FOR

Accuracy Dependability

and Long Service

THE WORLD-FAMED RADIO COMPONENTS IN GREEN CASES

OBTAINABLE AT

8 p.m.-Chinese programmie-Studio SINCERE'S

Concert..

"Concert

9p.m.-Evening weather, report and

local. time.-Studio (Chinese) continued. 10.30 p.m.-Close down.

SOLE DISTRIBUTORS

BUY BRITISH & BE PROUD

We have just unpacked a Shipment of

ALUMINIUM BASE-BOARD & PANELS. Suitable for Short Wave Receivers and other sets that require Screeding &

OTHER RADIO & WIRELESS PARTS

(Guaranteed British Made).

6.30 p.m.-Children prg ORIENTAL COMMERCIAL & Co., LTD

gramme. Auntie Pat, Uncle Dick and Uncle Jeff will-enter. tain the childrens

If

BANK OF CANTON BUILDING,

TEL. 24405.

NOT A NOTE IS LOST-

So Perfect are the Reproduction" Qualities

LOEWE FE 63 9 tube set

is used

MADE IN

ENGLAND

Sold by all

Wireless Dealers.

O

Valves

with the TENACIOUS

COATING

WRITE for "OSRAM WIRELESS GUIDE * (1929 Edition), Sent Post Fra.

SHORT-WAVE STATIONS.

· TIME (Hong Kong)

STATION

CALL BLON

OF WORKING

47.85 Doblatz (Germany)

A.F.K.

4,434 Mon, Wed. & Fri., p. & 2 azi,

60.12 Khabarova (Russia)

B.4.17.

4,000 6-10 p.m.

68,7 Nauen

A.GJ.

6,281 Not regular

GO. MOSCOW

RFN.

8,000 Tue, Thura, Sat., 8 m.

43.5

Bome

1.M.A.

6,896 Sunday midnight

Perth

6.L.G.

7,142 Daily 6.30p.m. & 11 pin

41.3

Singapore

7.8.1.AB.

7,310 Not regalor

38.6

37,

Bangkok (Siam)

Kootwijk (Holland)

P.C.LA

5.4.P.J.

8,108 Tues, &. Fri., 9p.m. a.m.

32.5

Sydney

2.B.I.1.

81.55 Melbourne

31.49 Schenectady

7,730 Daily 1 p.m.

3,220 Not regalar

3.1.0 9.508 Not regular W.E.X.A.F.

31,20 Eindhoven (Holland) | P.C.J. // 31.23 Sydney

31. Nairobi (Kenya) 7.L.0.

28.7 Sydney

27.8

Bandoeng

9,630 Daily 7.

9,620 Fri 3am, Sat, 8 am, & 10 am,

9,690 Not regular

0,677 Midnight daily.

2.F.C.

2.M.E.

.10,528 Not regular

P.LE.

26.43 Chelmsford (England) 6.8.W.

11,020 Midnight-3 am daily

11,751 7.30 pin. & 3 a.m. daily, except

Saturday and Sunday

K1X.E. 12,240 Fightly

W.2.1.0-12,850 $am. Wed., Fri., Pab

P.L.O.

18.4 Kootwijk (Holland) | P.C.L

16,102 Daily 6.30 pm to midnight 16,304 Daily 7 pm

17-20 Daily 8 p.m. to midnight

17751 Shodaya aidoight

24.6 Maala

23.36 Schenectady

18.88 Bandoong

174 Bandoong

P.L.F.

50.9

Bangkok

HSL

416-98. Hulen (Holland) ***

P.H.I.

16.3 Kootwijk (Holland)

18.74 Bandoeng

PLE.

15.6 Nancy (France)

18.03 Pittsburg

W.8.X.K.

31,540 Not regular

17,789 Drily 10 p.

Data Verfion

19,220 Daily 480-7 p.

19,361 Daily 3 I.

[Allowance must be made for summer-time" in most Eure-

countries, which is one hour ahead of true time.].

REQUIRES FRAME AERIAL ONLY WITH NEW BARIUM TUBES, CAN ALSO BE USED WITH LOEWE SHORT WAVE ATTACHMENT.

Demonstration Hours

11-11.30 a.m.

12.30-1.30 p.m.

5-5.30 p.m.

During demonstration hours expert European advice is given

on all Wireless matters.

Loewe R 533 A.C. set $126 without Loud Speaker, with Loud Speaker $150-

gives splendid volume.

"Pertrix" High Tension Dry Batteries:

150 volts, 100 volts, 60 volts and 45 volts. Heavy Super Duty

and Grit Batteries 9, 12 and 30 volis.

PARTS „RECLIVING, RITA

and

- ПРЕДКИ

CANTON TRADING ASSOCIATION, LTD.

CARL SCHROTER, Manager-5TH FLOOR, CHINA BLDG.

TELEPHONE 24610.