TUESDAY, NOVEMBER 6, 1928.
Red Hackle
SCOTLAND'S
LEADING SPIRIT.
THE famous "BLACK WATCH" Highlanders are distinguished
by the "RED HACKLE" worn in their bonnets. They were award- ed this unique badge for their gallin try in Flanders in 1795, Twelve.de. tades later they were hack in Fland. ers serving their, country with the same splendid spirit.
Demobilized in 1919, a number of ex-Officers and Men set themselves the tank of providing a spirit worthy of the regiment. After exhaustive tests by experts, "RED HACKLE" Whisky was produced, and is now controlled entirely by men who served in France,
"Red hackLE" has all the easen. tials of perfect Whisky. Distilled in the Highlands, from home-grown bar. ley and pure mountain water, its de licate flavour and axquisite bouquet de light and satisfy.
WHISKY
Supplied to The House of Lords.
Proprietors :~~~HEPBURN & ROSS, Kelvinbridge, Glangow.
Agents-W. R. LOXLEY & CO.
DAILY CROSS-WORD PUZZLE.
(This cross-word puzzle has been made by an expert but our readers are warned to look out for occasional phonetic spellings, such as harbor, plow, and altho,) |
12
B
14
15 16
7 8.19 To
11
12
13
IF
15
16
17
18
19
20
21
22
225
26
28
[29
31
27
3
35
136
37
38 39 40
P
142
45
146
47
150
153
55
HORIZONTAL
1-Crush
4-Poisonous plant of
U. S.
7-Early Peruvian
race
11-Again
12-Droll fallow
14-Instrument
15-Underhand
10-Variety of illy
18-Part of verb "to be"
19-Swelling an eyelid
20-The Pope
22-Projection.
24-Win
25-Annoy
27-A univeralty
28-Hostile incursion
30-Genus of, grasses
$43
148
52
54
THE INTERNATIONAL SYNDICATE.
HOMIZONTAL (Cont.)
+J-Timid
45-8aad covering
47-Ananethetto
48-Garden Implement 145-Mountains between
Europe and Asia 51-Gloomy |52-Disappear gradually
63-Rational
*EHTICAL (Cont.) 19-Naglect }20-Magnificent housan
21-French hackney
coaches
23-Officer who
supervisas harses 24-Channels of travel 26-Fatigued 27-Affirmative 29-8pecified time 36-Perlod of equal days 33-Woody, plant
34-Low murmuring
sound.
54-A gem
and nights
VERTICAL
1-Dracendant
2-Ralen up
4
S-A stroke of luck
4-Endure
6-Merely
which includes oats! &-Damure
31-To bend, as the neck 8-At the present time
32-Religious
organization*
-Take basty
35-Citizen cf.bio
37-Petitionad
38-Cane
41-Searchers
10-Likewise
9-Outer garment
112-Staff
13-Flippant
15-Popular form of
Ice-cream servics
17-At a distance
95-Wagers 37-Plant
89-A musical work |40-Mra. David
Copperfield
42-Cloth used for
uniforms
43-Hot-weather
favorita
|44-Lean on one alde
48-Masculine nansa
(short)
48-Chance
50-Famous generat 152-Shrewd animi
(Twe solution of the above cross-word puzzle will appear in to-morrow's issue along with a new cross-word puzzle.)
THE CHINA MAIL,
RADIO TOPICS
SCREENED GRID V. NEUTRALISED H. F.
[By Ultimax]
+
One of the most difficult questions to decide when about to design a receiver with one stage of H.F. must surely be the method of H.F. ampli- fication. With the advent of the new screened grld valve, we are presented with average characteris- tics of 290,000 ohms impedance with a magnification factor of 200, and at first sight our problem would appear to be solved. It cannot be denied, however, that when we begin to look into the matter more closely and compare this form of H.F. amplifica- tion with the ordinary neutrodyne, is so far as efficiency, selectivity, ease of handling, necessary screen- ing and other methods of attaining. stability, and last but not least, the cost; all these points must inevitably be taken into consideration before. we can approach the final decision.
Each method of amplification has certain factors which are very much alike, although at the same time each has advantages denied to the other, and it will serve our purpose if we briefly run through the various headings, and endeavour to decide the final form which the H.F. side of the receiver will assume.
Efficiency
So far as efficiency is concerned, the magnification given by the screened valve depends on the im- pedance in the anode circuit, and the amplification increase with the im pedance. Taking a standard tuned anode circuit with a single layer solid wire coll, a magnification of 45 to 50 can be obtained: The high cat possible H.F. amplification with a normal valve, such as PM5X used in conjunction with an H.F. step-up transformer with neutrallied wind- ings of the most efficient turns ratio is about 88. There is therefore no doubt that the screened grid valva will score on the point of efficiency.
Selectivity
From actual tests, using either grid leak or anode band rectifica- tion, the neutralised circult gives better selectivity, and unless
As, however, the regional scheme screenfor, but with the new H.F. will not..be completed for at least transformer mentioned, no screen- another three or four years, we ing is necessary, greatly increasing shall have plenty of time to con- the ease of construction of the re-
aider the position, but it will be
seen that selectivity will become a fundamental point in considering the design in future sets. ́
Base of Handling
celver.
With the tuned anoda screened grid valve elaborate, screening. "is required to obtain stability. We can reduce the necessary screening It is sold one advantage of the by using astatically wound coils, screened grid valve is that stable but this will increase the H.F. re- operation can be obtained without sistance and tend to lower the this necessity of adjusting a. neu-amplification figure. Similarly, the tralising condenser. This point provision of a variable resistance to may appeal to the unskilled user of control the oscillation caused by a manufactured receiver, but to the inadequate screening will bring man who builds the set, the opera-down the possible amplification of tion of neutralising the normal the screened grid valve.
Father of Television.
Dr. E. F. W. Alexanderson, the scientist and inventor, with a televising projector tubo. The projector includes a disc with 48 lenses, the picture being transmitted through a ground glass
screen.
+
care is taken to get the correct HF, valve is so simple that we voltage on the grid serven of the think this much advertised point of new valve, selectivity will be com-superiority is of small considera- paratively poor, especially with grid tion, so far as the amateur builder leak detection. This point regard-is concerned.
re-
Radiation
So far we have not considered the use of reaction. If we apply reac flon to the circuit to reduce the loss resistance we shall increase the effective resistance and the actual amplification will be greatly augmented. It will be appreciated the higher the impedance the greator. the tendency to oscillate, so, that when we increase the amount of reaction and the detector circuit goes into oscillation, with our ex- perience of receivers of the "W.T.6" type, we would naturally expect the disturbance to be radiated by the serial, with the usual interference to eats in the neighbourhood. Actually this does not happen. The back coupling laalde the screened grid valve is so small that although the plate circuit is oscillating the grid circuit is unaffected. In a similar manner, by adding re- action to the neutralised circuit, we shall enormously increase the amplification, and provided the valve is properly neutralised, we can throw the set into oscillation, and readily pick up distant stations by listening for the heterodyne note. The familiar whistle will be con- fined to the set, and there will be no fear of it reaching our neigh- bours, (Precautions must of course, be taken to prevent direct pick-up, such as might occur by running the aerial lead-in close to the detector valve),
t:
Relative Cost
The screened grid valve costs 22s. 6d. and to this must be added an
amount to cover cost of screening, say 73. 6d. Against this we have the ordinary valve coating 10s. 6d. plus 48. 6d. for a neutralising coo denser. The colla will be relative- ly the same amount.. It will be on that the screened grid circuit
ing selectivity will become of ex- A necessity in any modern treme Importance in the future, beceiver is the provision of induct cause of the introduction of the ances covering both the broadcast will cost twice as much as the neu- Regional scheme. The only definite band and the higher, wave lengths, trodyne. To most of us the ques information at present is that we with a switch to obriate the bug-tion will arise, "Is it worth it?” may get five main broadcasting bear of changing coils. The step-
up transformer necessary in the neutrodyne is a more complicated affair than the tuned anode coll, and, with one exception, no neu- tralleed receiver has been published. covering both wave lengths without going to the trouble of changing coils. An efficient H.F. transformer with astatic windings on the broad- cast band, and incorporating a simple switch placing the windings
stations using two wave lengths (10 in all) with a power of 50 kilowatts. The difficulty in "cutting-out" these stations will be appreciated when we remember that the present main stations, operating between 900 500 metres, with the exception of 2LO and CGB, only use 11⁄2 kilo watts. The creation of stations transmitting this enormous power of 50kw, will mean scrapping all the popular Detector-LF. sets in series for the high wave lengths, used in Britain if we wish to use them for other than purely local reception because of the necessity of good selectivity, a condition in- possible to achieve with one tuned circuit.
will shortly be available; so that in this respect the screened grid valve has no superiority.
Screening.
In the past, a neutralised circuft has required a certain amount of
9 H.P.
CLYNO
The Most Economical
First Television Drama Broadcast.
THE
HONGKONG
HONGKONG HOTEL: REPULSE BAY HOTEL;
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AND
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Tel. Add: "Victoria. Telephone No. C. $73. .
J.-H. WITCHELL,
Manager,
Courtesy, Comfort, Service... and Luxuries of Modern Hotel Construction
THE HOTEL RIVIERA
MACAU,
Cable Address :-"RIVIERA, MACAU."
THE IDEAL SEWING MACHINE FOR THE
Light Car.
L. C. LTD.
A
HOME
HAID & NEU
ALL NICKEL-PLATED Easy, noiseless - ruaning. Sewing forwards & backwards. Easy and extensive regula-
tion of the tensioni." All Spare parts in Stock. For further particulars apply to
BITZER & CO. Queen's Building;" · "
Ice House. Street, 2nd floor. *Tel C. 4655.*
Sole Importers for Hong Kong & South China..
NOTE THE DATE
November 7th, 3.00 to 7.00 p.m.
AT THE
HELENA MAY INSTITUTE MRS. W. T. SOUTHORN
HAS KINDLY CONSENTED TO OPEN
SALE OF WORK
IN AID OF THE FUNDS OF
THE NEW WESLEYAN SAILORS' AND SOLDIERS HOME,
Goods to suit every purse and every person, Teas will be provided at 50 cents per head
If,
for any reason you can't nurse your baby or he is not thriv ing on your milk-put him on
"BEAR BRAND" -
NATURAL STERILIZED MILK The results will gratify you !
Bolo Agents for H.K. & So. China A. B. MOULDER & CO., LTD. China Building, Hong Kong.
HONG KONG HOTEL VISITORS
L
November 5, 1928.
Messrs. A. M. Birchall,. M; Bon, Pierce Butler, Mr. and Mrs. J. P. Beruns, Miss Elsa Bowman.
Mears. R. J. Callen, D. Baker Carr, T. A. Chalmers, Robert K. Cook, W. B. Coleman, Mrs. I. Cook, Jr., Miss E. Cook, Miss M. Chickering.
Mosars. R. Devaux, A. Doujou, Mr. and Mrs. Duron, Mr. and Mrs. | W. S. Drake.
Capt. T. F. Evans, Mr. A. G. Ellinger.
Dr. F. J. Farr, Mr. Raymond Fuller.
Mr. and Mrs. J. Gibson, Messrs.
P. D.: G. Gain, Mr. A. W., Gibson."
Mears. A. F. Henry, J. L. Hunter,
| Miss Margaret Hall, Mr. and Mrs. W. Hausen, Mrs. J. S. Haslan, Mrs. John Harper.
Mr. Lindsay, Mr. and Mrs. G. Lyons, Mra. I. Leiter. Spra
Mra. L Maurin
Mr. and Mrs. H. H. Priestley, Mr. and Mrs. E. Pepperell.
Mrs. S. W. Robinson.
Messrs. E. Stuhlmacker, John Smith, N. Vander Steen
› Mr. and Mrs. R. C. Tillinghast.
Messrs. R
Whitham,
Wallock D Watts, Misses LL Woble and Helen
whose hands
at Opportune times.
nca by wireless: as
camera is in the cigarettes and offer
action
AT PRESENT, OUTDOOR WORK ONLY
K. FUJIYAMA
PHOTOGRAPHER.
NIGHT PHOTOGRAPHY AND EN- LARGEMENTS A SPECIALITY. ENLARGEMENTS CAN BE MADE FROM ANY PHOTOGRAPH. NEW, OLD OR FADED,
WEDDINGS AND GROUPS A FEATURE.
ASPECIAL ATTENTION GIVEN TO
DEVELOPING, PRINTING AND ENLARGING AMATEURS PHOTOGRAPHS AT A VERY : MODERATE CHARGE,
PROM
N
DELIVERY GUARANTEED.
I can give you as good. resulta as any Photographer in the City and better than 95 % of them. TEMPORARY OFFICE:
Brd FLOOR, 117, PRAYA EAST, HONG KONG
TASSEURS.
TANG.
TING.