1932-07-05 — Page 4

i

It'll Rain, but-

HONG KONG DAILY PRESS, TUESDAY, JULY 5, 1932.

THE NEW BROADCAST TRANSMITTER.

RECENTLY INSTALLED IN HONG KONG.

DUST COLLECTION IN HONG KONG.

MR. M. K. LO WANTS COVERED LORRIES.

This is a condensed message concerning condensed vapour, which falls upon the person

of the unwary and damps his spirits-if he lets it!

At whatever price you have in mind (within reason, of course) we can equip you with a stylish raincoat so that you can face the weather's threat with a smile.

}

Prices range from

$19.50

Less 10% Discount for Cash.

MACKINTOSH'S LTD

THE MALAYAN CAFE

IS

The Ideal Restuarant where you can have meals served at all hours of DAY and NIGHT and t MODERATE prices-And WHERE YOU WILL ENJOY SPENDING YOUR MONEY—WHY ?— Because WE serve the most DELICIOUS Meals. If words cannot convince you, come personally and try our special MALAYAN foods:-SATAI, PLOW, CURRY CHICKEN, SAMBAL UDANG, etc. Malay Kronchonge and English music in attendance.

Tel. No. 28690:

No. 2, Tin Lok Lane, Weichai.

DO NOT PAY

A CENT

UNTIL OUR SUITS FIT YOU PERFECTLY THAT IS WHY

WE SAY

OUR MAXIM IS PERFECT CUT-AND

BEAUTIFUL FINISH

SUITS

MADE TO ORDER

SAIGON LINEN

SUIT $15.00 To $20.00 WHITE DRILL

.SUIT $12.00

POPLINASTIA

BUIT $18.00 To $25.00

PONGEE

(TUSSORE SILK) BUIT 820.00 To $30.00

PALM BEACH

SUIT $20.00 To $90.00

HARIRAM'S

51, NATHAN ROAD, KOWLOON.

TEL. 56845.

FULL OFFICIAL DESCRIPTION OF. THE INSTRUMENT.

The Broadcast Transmitter was gise the serial circuit with the full designed and built by the Bar power of the plant at a frequency coni's Co. for use as a main broad- controlled by the Independent cast set to serve a, comparatively Drive Unit. large area.

J

The Unit Comprises:—

The component parts of the A single oscillation Valve, a closed Transmitter are mounted in four oscillatory circuit, including an unita cach consisting of an open adjustabla inductance, a condenser steel framework of rigid construc. and high frequency ammeter, coils tion. Special attention' has been for variable reaction coupling ta paid to obtaining purity of re- the aerial circuit, & Feed milliam- production, smoothness of working motor, an aerial tuning inductance, and reliability.

protecting condensera and re- The transmitter is of the coupled, sistances.

At to-day's meeting of the Sani- tary Board Mr. M. K. Lo will nak:

With reference to the end of the Sanitary Department's replies to my question on subject of Refuse removal at

meeting

of this Bouril:-

i.-Will the Head on the Sanitary Department inform this Board as to whether it is the fact that some of the lorries SYS already provided with covers whilst some are not so provid ed, and if this is the case will the Head of the Sanitary De partment state what is the number of lorries in ench category 1

circuit type and is provided with, The Valyo filament is lighted from the Independent Drive System for the main filament machino un ad- maintaining constancy of the rajustable resistance controls the volt-it-Will the Head of the Sanitary diated wavelength.

age across the filament and ñï D.C.

The transmitter is designed to voltmeter connected. across the fila- work on any wavelength between ment indicates the correct voltágo the limits of 300 and 500 metres; adjustment. and is similar in design to, but of greater power than, the standard Broadcasting Stations erected by the Marconi Company.

Rating:

Modulator Unit.

The function of the Modulator unit is to magnify the acoustic eur. rents received from the microphone

The transmitter is given a no-amplifier and to impress these on minal rating corresponding to the the carrier wave by controlling the cor rcial rating of the power amplitude of the oscillations gonor- gen rating machinery, which in jatod by the main oscillator. this case is 9 kw. utilised for: supplying power to the anode cir cuits of the Valves and for Recta fier. filament lighting.

The Unit. Comprises:-

Four Main modulating Valves, One Sub-Modulating Valve, and One Sub-sub-modulating Valve. In addition the tinit contains the necessary coupling and protecting condensers and resistances and a

In addition to the power generat- fing plant a D.C, Generator is used for lighting the filaments of the main oscillating. Drive and moauinodulation meter. lating Valves,

The following table shows appro ximately the power distribution to

the various circuits:-- To Aoria!

.2.0 K.W.

To Anode of Main Oscil-

lator

...2.3 To Anode of Drive Oscil-

Jator

..1.0

To Auode of Modulating

Valves

...2.3

To A. C. alament light-

ing.

..1,0

23

To D. C. Alament light-

ing

.1:75

The Transmitter :

The Transmitter comprises four units, namely:

a. The Rectifier Cait.

b. The Independent Drivo Unit

or Master Oscillator.

c. The Power Oscillator or Mag-

nifer Unit

d. The Modulator Unit; Rectifier Unit:

·

Department recommend to Gov. ernment that all scavenging forries should be so constructed or altered in such a way that the space for the storage of refuse is divided into a num ber of separato and self-con- tained compartments, with a properly fitted and tight-fitting

·lid for each compartment, and if not, why not? iii-As regards such lorries (if

any) which already possess lids or covers, will the Head of tho-Sanitary Department in- struct the officers in charge not to overload the lorries in such a way that the lids or covers cannot be closed properly?

measuring the total input to the Transmitter.

A Switchboard is also supplied for controlling the filament, battery lighting generator.

The Valve flaments are lighted from the main filament machine, ad- justable resistances controlling the voltages across the valve filaments.

A small rectifying unit is pro-

This Switchboard consists of vided for supplying high tension angle iron framework upon which D.C. to the anode of the Sub-sub-are mounted a number of panels of modulator valve at' 1,000 volts:

insulating material carrying the re- This comprises a small bi-phase quisite Switches, Measuring Instru rectifying valve together with the mente, Fuses and Regulating De necessa13 filament lighting and vices.

anode power smoothing circuit.

transformer

and

Microphones and Microphone Amplifers.

Power Transformer. Duplicate power transformers a Marconi-Reisz Microphones are provided, of the closed magnetic provided for use in the Studios and circuit, oil-cooled type, for the par-also for use on "outside" Broad- Pose of supplying high tension al-casts. The Microphone is a modern tornating current to the Rectifying design of the carbon type instru-

↑ Valves. Each is capable of deliver-ment, and has special features ing a continuous output of 10 which render it particularly suitable K.V.A. when supplied with al- for use in.connection with a Broad- ternating current at 300 volts, 300 cast transmitter. cycles.

The robust construction and ab- sence of delicate parts combined with the fact that the Microphone can be set up at any desired angle, make it specially suitable for port- able use.

all frequencies, whether of speech The Microphone is aperiodic, and or music, are faithfully reproduced in the Microphone circuits. The Microphone currents are applied to the input Transformer of a three valvo A" Amplifer the output of which is then amplified up by "B" Amplifier to a

The function of the rectifier unit is to convert the alternating cur rent supply at 10,000 volts into a Each Transformer is contated Unidirectional or continuous car with galvanised iron case fitted reat and to smooth out the "rip-¦ with suitable porcelain bushed high ple" due to the periodic variations and low tension terminals. of the E.M.F. generated.

The secondary windings are So perfect is its performance in divided into two sections specially this connection that not the sligh-insulated from each other and from test trace of "hum" can be detected the core of the Transformer, in in the carrier wave,

order to provide ample scurity. The Rectifier Unit comprises an against breakdown: open steel framework mounting:-

Two reotifying Valves for recti- || fying the high Tension alternating An Auto Transformer is provided means of a current from the power trans for the purpose of regulating the strength sufficient to apply to the farmer: A voltmeter for measur supply of high tension current to Modulating Valves of the Transmit itig the voltage of the high tension the Transmitter, and will be com-ting Set.

C. feed current: A stepdown plete with the necessary control" transformer for valve flament lighting: A Voltmeter for indica- ting filament voltage: An adjust able iron care choke for regulating

system consisting of two iron core inductances and three smouthing condensers; an Ammeter in the low tension power supply and a D.O. Feed Milliammeter. Drive Unity

gear..

Auto Transformer.

Motor Alternator,

The two Amplifiers (Stages "A" and "B" are arranged to be used either side by side at the Studio, or in the case of a theatre or con- the filament voltage: A smoothing, for supplying current to the Power placed conveniently near the Micro

A Motor Alternator is provided cert-hall-transmission is Transformer and the Rectifier Valve phone at the theatre, nnd "B" is filaments, and, consists of a direct kept at the studio, "A" and "B" Current Motor direct coupled to a being connected by ordinary land- 9. K.W. (11.25 KV.A. at 0.5 power The "A" Amplifier is a three

line telephone wires or cable. factor) 300 cycles, 300 volts singlo phase Alternator, the two machines ago Amplifier employing re- The function of the Independent being mounted on a common bed sistance capacity coupling and is Drive Unit is to control the wave plate.

provided with input and output length of the transmitter and to The Motor Alternator is provided mounted on shock-absorbing holders Transformers, The Valves are maintain it at a perfectly constant with the necessary Field Regulators, to protect them from undesirable value.

The circuit is one of the outstand-Motor Starter, and the requisite tibration A-mensuring instru

wavo-

ing features of the Marconi aystem spare parts, tools, and sundries iment is provided with a flexible lead ef transmission and enables grant Battery Charging Motor Generator, Constancy and stability of length and freedom from harmonica to be obtained, The init comprises !--

...

The flament lighting and Motor Generator comprise a motor direct coupled to a D.C. Generator "apable of delivering 100 amperes at 22- A single oscillation valve; volte. A closed oscillatory circuit; in- The motor generator is specially cluding an adjustable inductance, dasigued to avoid commutator rip a condenser and a high frequencyple, and is supplied with Field ammeter; Coils for variable rean egulator, Starter and all neces tion coupling to tlie power oscil-sary spare parts and tools What lator grid circuit protocting-con-Tripple is produced is smoothed by

The Valve filament is lighted condenser units.

means of high capacity electrolytic from the main Filament machine. An adjustable resistance controls the voltage across the flament and a D.G. Voltmeter connected "across the filament indicates the correct

densors, and resistances.

adjustment

Main Oscillator Unit:

The function of the main Oscilla www for Magnifler) Unit is to oner

Switchboards.

inserting it the appropriate socket, connected to a jack plug, which by

enables anode voltage, filament volt age, feed current and Microphone current to be measured

A Potentiometer. in the grid cir cuit of the first valve enabice am plification to be adjusted to the designed degree.

The "B" Amplifier is three stage amplifier and is provided with input and output circuits suitable for connecting to ordinary telephone lines Controls are provided on this amplifier which give a 100 to 1 ratio in strength

A Switchboard is provided for controlling, the main motor al 1.1.0 CERTIFICATES, terator and comprises an angle iron framework with panel on which are mounted the necessary Switches Indicating Instruments, Fuses and in addition a watt hour meter for

Placemonte, Baale. (Local agents Messrs. Goeke & Co.).

Monday's (June 27) official quota- tion_in Basle.-£2 Ds. 8d.

COLLAPSIBLE SILK LAMP SHADES very convenient for Export.

The B-B-C-Company

have recently produced many Collapsible Silk

Lamp Shades.

Your Inspection Cordially Invited

18, Ice House Street. -----

Phone 25122.

HUNG YU COMPANY.

SHANGHAI TAILORS. EXPERT MAKING EUROPEAN LADIES' HIGH CLASS DRESSES, CHINESE AND FRENCH SILK-MERCHANTS. 70. QUEEN'S BOAD CENTRAL. (OPPOSITE LEE YUEN STREET. WELT) Telephone No. 27803.

DRY CLEANING

for the

Business Woman

HE can't buy SHE

many clothes, but she can afford regular dry clean. ing-that's her

secret of smart- ness!

KEEPS YOU LOOKING YOUR BEST!

THE CHINA LAUNDRY CO. 16, Stanley Street,

Tel. 27608. DEPOTS: 7, Stanley St.

5, Luard Road,

Tel: 26054. WORKS: Whitefield Rd., Causeway Bay.

We invite you to come and inspect our wonderful display of UP TO DATE modern furniture and get idea for your HOME, how to decorate it and make it cosy

We beg to announce that Messrs. KOMOR & KOMOR, Art and Curio Experts, will also exhibit some choice. Art pieces suitable to beautify your HOME.

Showroom:Gloucester Building,

16. Des Voeux Road, C.

Tel. 28377- Studio: Tai Ping Building,

16, Queen's Road, C.

Tel. 28326.

ATHENA

IN

GLOUCESTER BUILDING

18, Des Voeux Road: C.