HONG KONG DAILY PRESS, THURSDAY, SEPTEMBER 11, 1930.
IMPROVING
RADIO
THE
FEATURES
AERIAL..
AIDS TO BETTER LONG DISTANCE RECEPTION.
[BY COHERER."]
acrial is oiten used: This, of
SOME USEFUL HINTS.
The pearer you can get to the maximum H.T. recommended by the valve maker the better for re- production, provided that you are careful as to grid bias as well.
Terminals should. never be fled
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TO-DAY'S WIRELESS
PROGRAMME,
BROADCAST BY Z.B.H. ON .335 METRES.
11 to 11.30 am-Commercial News 11.30 am to 12.30 pim-Chinese
programme. 12.30 p.m.-European programme,
course, is a mistake as high insula over a.panel when variable condon-1.30 pm.-Weather, report.
Aerial Insulation.
Dealing first with the preservation is of equal importance at any tion, the subject of insulation point where the aerial has to be an earth connected against earth and provision for a secured to
body. path to the set only will be the first thought. I have been asked
Aerial Height, the number of insulators that is
Although the point need noi necessary between the aerial and
cause undue care to those who are content with local reception on a support at each end. "It is not so much the number as the amount of insulation that is of importance. fairly powerful set, for long dis
tance reception the height of an Where a good porcelain insulator of high breaking strain is employed aerial is of the utmost importance.
Although the subject of aerial erection, has already been dwelt
these columns upon in
some six months ago, from a reader's request far farther details, coupled with the not unreasonable, assumption that since the article referred to radio topics has developed a wider interest, it would appear
that further remarks on this important adjunct to radio reception will not
there need be no duplication, be amiss. Naturally, only radio re-
"It appears to be a common prac ception is considered in these arti- tice among some amateurs to use cles and, with regard to aerial and two or even three small insulators earth systems, this fact obviates the size of an egg at each end of the necessity of delving deeply into
the aerial which, although increas the technical intricacies of calculating the insultation against earth, ing inductance and capacity to the offers no increase in the breaking nearest micro-micro-farad or henry. strain.
At the same time, it is 25. well to bear in mind that it is mainly on these two electrical characteris tics, inductance and capacity, that the efficiency of an aerial and earth system depend.
Aerial Tuning.
Proof is the finest preserver of knowledge and any reader who has had occasion to alter his nerial or connect his set to a 'different aerial will have noted the slight deviation from the normal tuning of his coils and condensers that the aerial change will make. Remembering that the aerial is the first link in radio reception and that at this point in the receiving installation the radio energy is weakest, it is not difficult to realise that every care should be taken to preserve as well as trap the electro magnetic
waves.
A large insulator, the size of a low frequency transformer will com- bine the qualities of high insulation and a reasonable safeguard against collapse when subject to any strain.
Care of Insulators.
An important point to bear in mind is that whatever the insulat ing medium employed it should be kept clean.
13 $
By height is meant the distance above the root of the housing of the set and not the height above sea level.
sers are mounted, or the dust will get on to the vanes of the variable condensers and cause trouble.
It is impossible to receive good quality signals whilst the set is oscillating.
Constructors will find it a good plan to mount all terminals and file the ends ready for soldering before other components are fixed in place.
tortion.
The local licence regulations allow
Do not use old or doubtful fixed for an aerial length of one hundred
or radio reception. feet which is more than sufficient!
This length condensers for coupling, as the includes the down lead and should slightest fault in component used be considered as the total length in this position will result in dis- from the further aerial support to the aerial terminal on the set. Those who are favoured with suf scient space and other conveniences will find that a horizontal length of 50 feet with a down lead of 30 to 40 feet will provide a perfect aerial that will do justice to the best of sets.
The Lead-in Circuit.
The down lead should be kept as possible and early vertical should on no account be allowed to run back under the aerial proper, it being drawn away from the main length.
The carbon, deposit that naturally collects on an arti cle so exposed to the elements for any length of time, acts. partial conductor with the result that much of the high frequency energy will find a path to earth
At the point at which the serial other than through the set. Where it is necessary to employ subsidary enters the room in which the set is installed many amateurs seem to insulators such as on a stay to haul the aerial clear of buildings where countermand any care that may leading in to the house a smaller have been taken in the remainder
of the aerial. Insuficient insula amount of insulation to that emtion when boring through a window ployed at the main part of the
EVERYTHING GE.C
your guaranter
ELECTRICAL
TENACIOUS COATINGTM
KEEPS YOUR SET
AT PEAK PERFORMANCE
It's not
the filament but the coating. on it that
MADE IN ENGLAND
Sold by all Wireless Dealeri,
counts
Osram
Valve
Osram
valves
with the "TENACIOUS
COATING
Holes accidentally made in a panel need not spoil its appear- ange, for these can be filled up with sealing wax, or heelball as used by shoemakers.
*
*
The small holes in accumulator. vent plugs should on no account be stopped up, as by allowing the gas to escape when the accumulator is being charged thy play an import- ant part in its operation.
•
Always remember that great,care It should is necessary in handling of electric light or power wiring. not be undertaken by inexperienced persons.
*
#
When trouble is experienced on a mains unit in conjunction with noisy mains it can often be over- come by connecting two large con densers in series across the mains and earthing the centre point.
If you must have joints in either sash or a cheap tro-way carthing your serial or your earth wire, be switch, the terminals of which are sure they are soldered ones. allowed to corrode, are sources of conaiderable loss of high frequency, energy. The best method at this point is to employ one of the many excellent lightning arrestors that are. on the local market These components being completely en- closed have the advantages of free- dom from the harmful, effects of corrosion, do not require continual attention as regards switching on and off and offer a perfect safe- guard against any danger from lightning From the arrestor, the wire to the set should be of very heavy rubber insulated or passed through an ebonite tube
at the
point of entry. Joins in any part of the aerial circuit should be avoided and where unavoidable the greatest care should be taken to make a clean tight joint well secur- ed with solder. Sharp projecting points much as at the insulator terminations should also be avoid- ed, these offering a means of radis- tion for some of the energy col- Jected.
A Short Wave Aerial. To really keen short wave enthu- Biasta the Half wave aerial" will offer immense possibilities of im proved reception. This type of aerial is so constructed that its hori- zontal span is exactly half the length of the wave it is desired to receive, the down lead being con- nected at the dead centre.
2 p.th-Olose down,
0 to 8.30 p.m.-Aunty Pat, Uncle Jeff and Uncle Dick will try to entertain the Kiddies.
Europeon programme of
and H.M.V.
Victor records selected atd supplied by Messrs. Moutrie & Co.
The Daughter of the Regiment (Donizetti), La Scala. Orches- tra, Milan.
Dear Little Cate and I'll See You Again, Peggy Wood and George Metara, Vocal Duet:
False Trieste (Sibelius) and A
Keltic Lament (Foulds), Victor Olof Sextet, Instrumental. Poem (Fibich) and An Autumn Serenade (Becce), Reginald Foort, Organist.
Wait (G. D'Hardelot) and In An Old-Fashioned Town (Squire), John Turner, Tenor.
A Word Allow Me and A Song of Tender Mem'ries (Leonca- vallo), Peter Dawson, Bass Baritone.
H.M.S. Pinafore Selection (Sul- livan), The Band of H.M. Cold- stream Guards.
The Boys of the Old Brigade (Barri) and When the Sergeant Major's on Parade (Langstaffe), Peter Dawson, Bass Baritone. Policeman's Holiday-One Step)
Wee Macgregor Patrol. The Band of HM; Coldstream Guards.
pre
Toasts and Down in Our Village
in Zummerzet, Norinan Long, Humourons..
Announcing the Arrival of
FIRST SHIPMENT
OF
ATWATER KENT
RADIO
The Very Latest in Modern Screen Grid Radio; Distinquished by
COMPACTNESS, SIMPLICITY
AND TONAL PERFECTION.
Every Set Carries a Warranty from Manufacturers.
You have known the Name of Atwater Kent, But have You seen the Famous Apparatus?
Come and Then Inspect It.
Old Time Songs, Jack Hylton and THE SINCERE Co., LTD.
his orchestra.
Early Ragtime Memories, Jack
Hylton and his orchestra.
8 p.m.--Chinese concert.
9 p.m.Weather report, local time.
Chinese concert, continued, 10.30 p.m.-Close down.
HAVE YOU HEARD THESE?
Here are lists of long-wave and short-wave stations which should be picked up by anyone in Hong Kong who has a mode- rately good sot suitable for re- "ceiving such signals, Success in picking up these stations also depends very largely upon fav- ourable atmospheric conditions. Eeaders are invited to add to. this list should they aucceed in picking up any station not in cluded in either of these Hats.
LONG-WAVE STATIONS.
Wave length
Call Kilo- (Metres) Station Siga cycle
KZ.I.B. 1,153
960. Manila
277 -Shanghai - K.S.M.S. 1,085 250 Tientsin. C.R.O.. 1,070 310 Shanghai K.R.C .967 320 Paping C.O.P.K. 945 345 Tokyo J.O.A.K. 870. 353 Hiroshima J.O.F.K 850 $16 "365 Hong Kong Z.B.W.
357 Bombay
840 301 Sapporo
208 Keijo
370 Nagoya 370.4 Calcutta,
V.U.B J.O.I.K. 830-
J.O.D.K. 820
J.O.C.K. S10 V.0.0.
809.9
380 Kumamoto J.0.0.K. 780 3.0.H.K. "770 J.D.A.K. 760 V.U.R. -784 J.O.B.K. 750
C.M.B.
·K.ZR.M.
390 Sendai 365 Dairen 398: Rangoon 400 Osaka 410 Canton 413 Manila SHORT-WAVE STATIONS.
STATION
CALL BIGE
Kito
начало
TIME (HONG KONG)
OF WORKING
A.F.E. 37.85 Debintz (Germany)
448 Mon, Wed., & Fri, 6 p.m. & 3.m. 4,990 6-10 p.m. 30.12 Khabarovsk (Russia)97 56.7 NAUGH
A.G.J." 8,291 Not regalar REN. 1.M.A.
50.
Moscow
Esme
6,000 Tue, Thurs., Sat. 8 p.m. 6,896 Bunday midnight
Opinion has been solicited as to the local possibilities of the counter. poise aerial as a means of earth connection where a direct ground earth is not possible. It is gener- ally found that where a direct ground connection is not possible the erection of a counterpoise also, presents many difficulties, the lat ter being a length of wire, stretched parallel to the aerial some twenty feet below it and about ten feet above the ground. Providing this as -factor can be overcome the counter-
41.8 poise has much to recommend it as an alternative to the earth condér: tion, especially where the soil in
8230 Not regülar hard or apt to be dry for long
B.4.0; 9,603 Not regular periods. In all serial systems the
17. W.2X.A.F. 1,530 Daily
Sat 8 am, & 10 nm) wire employed from the further 81.20 Eindhoven (Holland) PC.J. $9,820,8 support to the connection to the
81.28 Sydney
2.7.0.
2,690 Not regular house should be of hard drawn a Fairobi (Honya)
7.1.0. 5,077 Midnight daily Bydnay phospher bronza, preferably in an 28.5
10,626 Not regular Bandoong 27.8
13,020 Midnight am daily unbroken length.
26.63 Chelmsford (England) 5.6.W
11,751 7,30 pm, & 5 m, daily, except
Saturday and Sunday
"D.X." MAUsed
SEPTEMBER NUMBER
ISSUED.
The September number of "D.X" has now been issued. Radio fans will find in this journal much to interest them diagrams accompany the articles, and there, is a special chapter on radio simplified for the beginner,
DX is on sale at Mesars.
WRITE for OSRAM WIRELESS GUIDE. (1929 Edition). Send Post Fraas Kelly & Wash at 50 cents per copy.
38.8
37,
32.
(Holland) Hangkok (Siam): Sydney 3165 Melbourne
Schenectady 8148
61.20
245
Manila:** 23:35 Schenectady,”
V.8.1.A.B.
P.C.I
7.112 Daily 6.80 p.m. & 11 pm. 7,310
#7.780
Not regular
11
30 am..
HSAPJ. 8,108 Tues
5.M.E. PLR:
m. Wed., Fri., Bat. 16,102 Daily 6.30 pm to midnight 16,304 Daily 7 p.m. z
17280 Daily 8.m to midnight
KIAB
12,240
WAKO. 12,850
Nightly
-18.88 Bandoeng
PLG.
184
Kootwijk (Holland)
P.C.L
174 10.0
Bandoeng
P.L.F.
Bangkok
16.89 Haizea (Holland)
P.F.L.
17,709 Dzily 10 pm.
Kootwijk (Holland)
P.C.K.
18,404 Each afternoon
16.74 Bandoeng
PLE
13,200 Daily 6.80 p.m.
18.5
Nancy (France)
19,861 | Dally 8 am...”:
13.88
itaborg
W.8.I.K.| 21,540 | Not regular
16.3
H.SLPJ 17,751 Sundays 7 p.m. & midnight
(Allowance must be made for sommer-time" in most Euro-
pean countries, which is one hour ahead of true time]
SOUTH CHINA SOLE AGENTS.
A RADIO
THE
LOEWE FE 63
9 tube set
A new shipment, just arrived, is one of the most sensitive instruments for long distance and recep- tion with six stages of high frequency.
This set is fitted with new Banum-tubes and requires,
a Frame Aerial only. Can also be used with LOEWE short wave attachment.
Newly arrived
Loud Speakers of various types.
Pertrix Batteries 150, 100 7. and Grid Bias Batteries, Gramophone pick ups of best quality..
Gramophone Electric Motors.
B' Eliminators a speciality to fit any requirement,
Demonstration Hours :—–
11-11.30 am. 12.30-1:30 pm.
5–5.30 p.m.
During demonstration hours expert European advice is given on all Wireless matters.
THE
CANTON TRADING ASSOCIATION, LTD.
CARL SCHROTER, Manager –
5TH FLOOR, CHINA BLDG.
ELEPHONE 24610.