Haig
SCOTCH WHISKY
JOHN HAIG & Co.Ltd.
(Deming Malg & Maig, b54 „}
MARKINCH, SCOTLAND.
470
THE HONG KONG DAILY PRESS, THURSDAY, MAY 15, 1930.
RADIO
Consumers are requested to see that every buttle of Joàn Haig Gold Label Whisky os supplied by us bears the foot label thus: "Gande Price & Co., Ltd., Sols Agents for Hong Kong."
་་
SOLE AGENTS:
GANDE, PRICE & CO., LTD., "St. George's Building, Ice House Street, DIAL 20135.
HONG KONG.
Five hundred and eighty-four leet of luxury!
TATSUTA MARU ASAMA MARU CHICHIRU MARU
THE SILK EXPRESS TO AMERICA
HONOLULU
VIA
N.Y.K.
BUY BRITISH & BE PROUD
We have just unpacked a Shipment of
ALUMINIUM BASE-BOARD & PANELS. Suitable for Short Wave Receivers and other site that require Screening
&
OTHER RÁDIO & WIRELESS PARTS
(Guaranteed British Made).
ORIENTAL COMMERCIAL & Co.. LTD.
BANK OF CANTON BUILDING,
TEL. 24405.
HONGAY SMOKELESS EGGS COAL
FOR
HOUSEHOLD USE.
KEEP THE HOUSE CLEAN AND NEAT!
NOTE CHEAP PRICES
FEATURES
ABOUT THE THERMIONIC VALVE.
IT'S EARLY HISTORY AND DEVELOPMENT.
[By #-GOHERER.”)
The First. Valve.. It was nearly twenty years ago | alter Hertz's discovery of electro-
Without delving too deeply into magnetic waves, which may be com
the electron theory, on which the dered as the birth of wireless, notion of the valve depends, the that Dr. Flaming in 1901 revolu-functions of the original tube may tionised science with his invention be briefly summarised as follows. of the Thermionic Valve for the rectification of wireless signals..
Previous to this invention and, in fact, for many years after (for sour years were spent in perfecting
The heat caused by an electri fed wire (Elament).sets up in the space about it a negative electrical charge. The plate, which is placed in close proximity to the filament,
to these negative charges (elec trons) in a manner somewhat simi- lar to the attraction of iron filings to a magnet.
Those who are familiar with the action of the present-day valve will see that in this first invention of Dr. Fleming the duty of the grid ivas shared by the filament and the plate..
Introduction of the Triode. Dr. Lee De Forest was the first three electrode to introduce the valve, inserting a metal, coarsely. meshed "grid in the path of the
filament and plate.
This grid.being connected to the tuned circuit carrying the induced
it) rectification, or detection as being charged to a positive poten. electronic. flow, namely between is more commonly termed, dependtial, provides a source of attraction ed in turn an the coherer, the crys tal and the magnetic detector.
Each of these merited the term valve," inasmuch as their action allowed, the passage of a current in one direction only. thus rectifying the received alternating current into one of unidirectional capable of developing sound response in a pair of telephones."
It is only the thermionic tube that is known as a valve to-day, the other forms of detection being prae- tically obsolete.
The valve in its earliest form con. sisted of an exhausted glass con- tainer-much the same "as is used in present practice, but containing only two electrodes, "a copper anode or plate, and a tungsten filament.
Although this type of valve was never very extensively used in wire less reception, it being soon im poved upon by the introduction of 5 third electrode (grid),,its action forms the basis of the many modern developments in valve design,
This continual flow of energy sel
up from filament to plate is termed the thermionic current, sometimes referred to as the electronic flow.
In the original valve it was found that if one end of the coil in which electro-magnetic waves were in- duced (aerial tuning-coil) was con nected to the filament, and another" connection was made from the plate to the other side of the coil, a cur rent was set up in this latter con- nettion which was rendered audible by connecting a pair of telephones acrpasib va n
TO-DAY'S WIRELESS
PROGRAMME.
BROADCAST BY ZB W. ON 335 METRES.
11 to 11.30 a.m.-Commercial News.
11.30
... to 12.30 p.m.-Chinese programme. 12.30 to 2pm-Programme at
Columbia records supplied a Messrs. Anderson Music Co. to 6.30 p.m.-Children's hour. 30 to 3 p.m.-Programme of Columbia records supplied g Messrs. Anderson Musie Cart- "Maximilian. Robespierre — Over. ture (Litolf), The National Military Band (conducted by Albert W. Ketelher). Come Into The Garden Maud " (Tennyson and Balfe) and "My Sweetheart When A Boy (Enach and Morgan), William Heseltine, Tenor with Orch. Get Out And Get Under The Moon' (Tobias, Jerome and Shay) and "Some Day You'll Be Sorry" (Seyler and Mor- gan. Layton and Johnstone.. American Duettists with Piano.
Pinan Theatre Orchestra.
or received aerial current. it fol-Gipsy Suite" (E. German). The lows that it will be subject to an alternating current, thus repelling er assisting the electronic flow within the valve.
These Auctuations affecting the potential on the pinte, variations of current, in the telephone circuit will, take place, causing sound dependent on the received or aerial current.
It will be seen that, in effect, the grid acts as a relay, very small changes in its current valve caus ing considerable response effect in the plate circuit.
#
Multi-Valve Arrangement.
Cr
The example taken is of a circuit employing only one valve; obvious-
It will be seen from, this that the valve was living up to its name inly the process can be repeated by cutting out half of the alternations a series of valves with suitable of the received current, thereby, as coupling arrangements, so that the mentioned above, rectifying the cur plate current of the first valve is, rent so as to affect a pair of head. passed to the grid of the next for phones.
further amplification, and so on..
HAVE YOU HEARD THESE?
Hord are sta of long-wave and short-wave stations which should be picked up by anyona. in Hong Kong who has a mode- rately good set suitable for r6- ceiving such signals. Success in picking up these stations also depends very largely upon fav. ourable atmospheric conditions. Readers are invited to add to this list should they succeed in picking up any station not in. cluded La either of these lists.
LONG-WAVE, STATIONS.
Wave
length
(Metres) Station"
900 Manila
977 Shanghai 280 Tientsin 310 Shanghai 320 Peping 345 Tokyo
ו,
いい Call Kilo- Sigo cycle
K.Z.I.B. 1,153
K.S.M.S. 1,085 C.R.C. 1,070 K.R.C. 967 C.O.P.K. 0-15 J.O.A.K. 870 353 Hiroshima 1.0.F.K 850 355 Hong Kong Z.B.W. 848 357 Bombay V.U.B. 840 331 Sapporo 330 Keijo 370, Nagoya 370.4. Calcutta 380 Kumamoto 300 Sendai
205 Dairen
J.O.I.K. 830 J.O.D.K. 820 J.O.C.K. 810 7.0.0 309.9 J.O.G.K." 700 J.O.H.K. 770 J.D.A.K. 760
388 Rangoon V.U.R. 754
400 Qaaka
410 Canton 413 Manila
SHORT-WAVE STATIONS.
STATION
CALL BIGN
KILO
J.O.B.K. 750 C.M.B. 739 K.Z.R.M. 726
Trus (HONG KONG)
or WORKING
4,434 Mon, Wed & Fri., 6 p.. & 2 a.m.
Once the three-electrode valve was established, muid strides were taken in development and valves with characteristics specially suited | for high-frequency amplification.. detection, or low frequency ampl- fication were designed.
4
The two-electrode valve principle. is only used nowadays for the recti Beation of high voltages, such as are used in transmitting-plants,
The further development of the valve and present-day principles in valve design will be discussed in another article.
QUERY CORNER. A letter from Screen Grid was received too late for attention, but will be replied to next week.
For Better Result
TRY MULLARD
• Frust-Vocal Gems (Gounod. English Version by E. F. Chor- ley Miriam Licette, Madam Clara Serena, Francis Russell and Harold Williams with Or- chestra.
Die Fledermaus - Selection " (Johann Strauss), Johann Strauss and Symphony Orch. Hedge Roses (Schubert)
"
The Trout (Schabert). W.. F. Watt, Tenor with Pingo. Golliwog's Cake Walk" (De- bussy) and "Daoce of the Turiblers" (Rimsky-Korsakov, arr. O'Donnell), B.B.C. Wire
rss Military Band conducted by H. Walton O'Donnell, The Student Prince
(Donally
and Romberg), Harry Welch- man and Theatre Chorus with Orchestra.
Four Ways" (Eric Contrs), Regal Cinema Orchestra conducted hy Emanuel Starkey.
"Land of Dreams (Gerard) and
Gossamer Winge (Gerard); J. H. Squire. Celeste Octet. 8 p.m.-Chinese prograinme. 10.30 pm.-Clase down.
LISTENING IN CZECHO- SLOVAKIA.
Broadcasting licences issued in Czeche-Slovakia up to the end of December last, numbered 207,962.
ROME'S NEW HIGH-POWER- STATION.
One of the most powerful wire. less stations in Europe. qualled enly by the biggest in America, was opened just outside Ron last month. The broadcast program. mes; which will comprise converts. lectures, political speeches, news, dance music, and excerpts from the theatres, will be chosen by a special committee with a particular view to interesting listeners from abroad.
TSANG FOOK PIA NO COMPANY,
8. Des Vœux Road Central- (Entrance Ice House Street) Telephone 24648.
Simplicity itself
One-motion tuning. Simplified circuit. Units all interchanger able.
There's nothing like
micro-synchronous
Victor Radio
HEARING IS BELIEVING
7,143 Daly 6.30 p.m. & 11 p.m.
7,810 Not regular
7,780 Daily 1 p.
10,626 Not regular
67.85 Dobintz (Germany) 60.19 Khabarovek (Buscia)
AFIK:
RAT
4,990 0-10 p.m.
66.7
43,5
In lots of not less than half-ton; delivered to.
42
41.3
Naven Moscow Вата Porth
A.G.J.
6,291 Not regular
RF.N.
5,000 Tue, Thura, Sat. 8 p..
1.MA
6,896 Sunday midnight
8.A.G.
Singapore
V.S.1.A.B.
38.8
Kootwijk (Holland),
F.C.L.
Peak District (above Bowen Road) Bowen Boad-and-Lower-Levels Pokfulum Road
Pra Tox. $23.00
37.
Bangkok (jam)
H.5.4.P.J.
8,108 Tues, & Fri., 9 p.m.---1 a.m.
az
Sydney
2.B.L.
3230 Not regular
Kowloon....
... $21.00 $23.00 *...'$19.00
31.55 Melbourne
3.LO.
9,603 Not regular
8148 Schenectady
W2XAF
9,530 Daily 7-1
31.20 Eindkaren (Holland)
P.C.J.
9,620 Fri 8am., Bat. 3 aó, & 10 am.
31.28 Sydney' |-
2.F.C.
9,600 Not regular
Orders should be sent in writing, not by Telephone, at least, 24 hours before the coal is required, and orders must be accom- panied by cash, cheque, or compradore order payable to BZE WAI & Co.
Please apply for prices of other descriptions of coal for bunker, factory, and other purposes?
TELEPHONE No. 25009,"
SZE WAI & CO.
49, BONHAM STRAND WEST, HONG KONG. (CANTON BRANCHEZE WAI & CO, Lok Yu SUM KOAD, CANTÓN
PHONE NO. 13650.),
Kootwijk (Holland) 15.74 Bandoung 15.5 Nancy (France)
13.83
Pittsburg
31.
Kairobi (Kenya)
7.1.0.
9,677 Midnight daily
28.5 27.8
Sydney
2.M.E.
Bandoeag
P.L. 1.
11,000 Midnight-8 a.m. dally
25.58 Ohelmsford (England) 6.8.W.
24.6
Manila 23.36 Bchenectady 18.88 Baadoeng
X.1.X.E
13,240 Nightly
W.2.X,0.
10.9
Kootwijk (Holland) Bangkok 16,88 Hulton (Holland) 10.3
P.L,G,
10,102 Daily 6.20 p.m. to midnight
PEL
17,769 Daily 10 p
T.C.E.
18,404 Each afternoon
P.LL.B.
19,220 Daily 5,30-7 p.m.
19,351 Daily 3am.
P.C.L.
H.S.1.P.J.
11,761 7.30 pan, & a man. daily, except
Saturday and Sunday.
12,850 m, Wed., Fri, Sat,
10304 Dally P
17,751 Bundays 7 pm, & midnight
W.8.I.I. 21,540 Not regular
THE BEST BRITISĘ MAKE
THE
MASTER VALVE
SINCERE'S
SOLE DISTRIBUTORS
AND A
LOEWE FE 63
9 tube set
will bring to your hearing all the best music. This set requires a Frame Aerial only with new Barium tubes. Can also be used with LOEWE short wave attachment.
Demonstration Hours
11-11.30 am. 12:30-1:30 p.m. 5-5.30 p.m.
THE
CANTON TRADING ASSOCIATION LTD
CARL SCHROTER,
Manager
5TH FLOOR, China Blog.
TELEPHONE 24610.