THE HONG KONG DAILY PRESS, THURSDAY, MAY 8, 1930.
ITSANG FOOK PIANO COMPANY,
& Des Vœux Road Central
(Entrance Ice House Street) Telephone 24648.
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Victor Radio
FEATURES
WIRELESS AND THE
THE CAUSE OF ATMOSPHERIC
BY COHERER.")
"At the discharge point positive and negative charges rush towards each other and neutralise, causing the sound known as a thunder-clap the resultant spark or flash-light
WEATHER.
INTERFERENCE.
The main effect of the weather on wireless as experienced by the broadenst Estener, is that grinding, crackling noise termed atmos- pherics. With the coming of the summer months' local radio recep-ning.
Although the sound and flash are tion, as many listeners are only too painfully aware, is getting increas- actually instantaneous there is a ingly subject to this interference. time gap in their evidence to our senses, due to the considerable dif. At home this annoyance is scarcely noticed, it being experienced not ference in their respective velocities more than a few nights in the whole-light 186,000 miles per second and sound roughly 250 to 350 yards per In this part of the world, how.second, dependent on the tempera- ever, we are not quite so fortunate, ture. and for as much as six months of the year reception of broadcast programmes is likely to be affected hy these disturbances.
year.
Although we are not concerned so much with the cause of this interference as its effect on our receivers, a few notes as to the source of this electrical energy should be of interest.
A theory is put forward that these discharges also take place, to a minor extent, within the clouds.
Atmospheric Intensity.
It has also been shown, from a world study of observed thunder lightning storras, that there are flashes actually in progress in some part of the world at any moment at an average rate of nearly 100
On the other hand, as already pointed out, atmospheries affect all tuned circuits alike, and this effect would be neutralised.
Theoretically, the principle is simple, but its application presents many complications which prevent its practice application.
Considering the millions of radio sets in daily use, and the very rare occations that one hears of one being damaged by lightning, the first long-element of danger from this source
may be taken as very slight.
as in the case of the novice who, when listening to, his distance transmission, excitedly de- clared that he could hear the rush of the waves of the sen
The elimination of these annoy- ing sounds is a problem that has given the subject for a good deal of research for years past, not, unfortunately, with any marked success. Many claims have been a perfect atmospheric made to eliminator, but all have failed as regards practicability.
This is obvious from the fact that even to the present day, during the electric storms experienced in the tropics, wireless communication is sometimes held up"for as much as three or four days. The main dif is that they have no particular ficulty in keeping out atmospherics or frequency. They will, tone. therefore. cause a receiving aerial to oscillate at its natural fre- quency, so that, whatever wave the receiver is tuned to, atmospheries jwill always pass through the re-
It is no doubt common knowledge That atmospheries are enused per second! those electric discharges through
Local short-wave enthusiasts who†ceiver. the ether which, when visible are
bave endeavoured to tune in Eng- Another serious item to contend koown as lightning, being an cle-land at this time of the year wil with in endeavouring, to apply some trification of the atmosphere. It is have no doubt as to the accuracy method for their elimination is not only during thunderstorms that of this statement!
their electrical strength. Esperi this electrification. takes place. Considering the above figures, it ments have shown that a current Even in very fine weather the at-is not surprising that atmospherics of about 10,000 amperes flows for mosphere is the source of con
ear-thousandth, of a second in i siderable electrical activity,
Hghtning flash, the average length of which is two miles. Taking the length of a flash as" a source of radiation similar to a transmitting aerial, the energy so radiated would be about eighty thousand times as strong as that from Z.B.W. {
are always experienced on a sen (sitive long-range set. The upper regions of the atmosphere, referred to above as the positive pole. of a huge battery, is known as the Heaviside layer," and is assumed to be that part of space about sixty miles above the earth's sur face.
This can best be described by taking the earth and the upper regions of the atmosphere ts. the negative and positive holes respec- tively of a huge battery. Clouds hetween these two poles receive a nsitive, charge in much the same -rw-az-a condenser-and-when-these What little deterrent it offers-to- charges become rufficicntly great radio in providing the atmosphere the pleatrical strain causes a dis- with a source of electrical disturb charge of spark.
ance, fa amply, made in for in the met that, without it, long-distance,
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mdio would be impossible,
Atmospheric Elimination.
That no efficient means have yet been discovered to nullify the effect of atmospheries on radio receivers must be a source of wonder, not to Eay exasperation, to many radio enthusiasts, for few if any, of us are able to appreciate their novelty
|
Neutralised Tuning.
•
At the same time it is as well during a local thunderstorm to switch off the set and earth the aerial.
Efect of Wireless on Weather. The general view of scientists as the to the effect of wireless on weather can be summed up in A similar manner to that in which a local entertainer gave a burlesque of a radio news bulletin one para- graph of which read:-" To-day's rainfall there has been no raic fall."
CAUSE
of
QUERY CORNER.
TWO VALVER.-The data you require, namely, for making an iron core F. choke of 20 Henries and 1300 Ohms, could better be supplied if you gave particulars of the wire available, the metal it is intended to employ, and the current-carry- itg capacity required. The wire ent is a high gauge constantin, an usually employed for this compon- alloy of copper and nickel.
The core is made up of soft iron stampings from specially selected and prepared metal with a low hys.
teretic constant.
It is very much doubted if either material is available in the Colony, and even so, it would be far ebean. er to buy one of the many Food makes obtainable at local dealers than to make one, the windin process being far too difficult to af- tempt by hand.
COHERER
Since the early days of broad-
ANNOUNCERS IN TROUME oisting there have been many who, claim to scientific basis for their London, have just had to undergo. although not having the slightest
Certain announcers at Shyo Bit views, have declaimed radio as
the
a rather terrifying examination “in- abnormal being weather. Especially was this the the pronunciation of foreign song case in England, where rainfall fees. The test was conducted be. above the average occurred during fore a number of lordly ones whose names alone might petrify anyone the first years of the B.B.C. The
cloud disturbance by gundre at gifted with the sang-froid. of theory of the same budding scient an announcer. There is reason to ists a few years earlier having believe that the examinees emerged proved fallacious with the cessation with their colours slightly droop- of hostilities, radio provided a hasising This will not distress the for the continuation of their views public. The public will side with Facts and figures have already been the all-British announcer who says
things as they are spelt." quoted quite suficiently for one. article to permit of a detailed dis- cussion as to the absurdity of these statements as set forth by leading scientists, but the proved fact that the energy per square mile taking place in the atmosphere resulting from rainfall is about 650 million times more than that due to a -normal-broadcast transmission should be sufficient to dispel any
The main theme on which experi- ments have been hased for a aum-ision as to ber of years in trying to avoid at-
oapheric interference is a system
of neutralised tuning.
Two tuning circuits are so wired that, if equal effects are produced in each, they will be in opposition to each other and so neutralized.
By tuning one circuit only to the wave-length required, the effects in each not being equal signals will be received on the one circuit in the ordinary way.
HAVE YOU HEARD THESE?
50.
Here are sta of long-waye and short-wave stations which should be picked up by anyone in Hong Kong who has a mode- rately good set suitable for re ceiving such signals. Success in picking up these stations also dopends vary 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 in either of these lists."
43.5
31.43 Schenectady
LONG-WAVE STATIONS."
Wave length (Metres) Station 260 Manila 977 Shangbai "250 Tientsin
310 Shanghai
Call Eilo Sign cycle K.Z.I.B. 1,153 K.S.M.S. 1,085 C.R.C. 1,0701 K.R.C.. 967
320 Peping C.OP.E ́015
345 Tokyo
J.O.A.K 670 353 Hiroshima 3.0.F.K. 860 355 Hong Kong Z.B.W. 337 Bombay V.U.B 361 Sapporo
363 Keijo
370 Nagoya 370.4 Calcutta
946
840
J.O.I.K
630
J.Q.D.K 820
J.O.C.K. 810
V.U.C
609.1
790 J.O.H.K. 770
380 Kumamoto J.O.G.K. 330 Sendai
365 Dairen J.D.A.K..7600
398 Hangoon
400 Osaka
420 Canton
413 Manila
SHORT-WAVE STATIONS.
| W.2.X.A.F. 3120 Eindhoven (Holland) P.CJ.
KILO
azubary
V.U.R 754
J.O.B.K. 130 C.M.B. 732 K.Z.B.M. 796
OF WORKING
6,000 Ties, Thurs., Sat., 8 pm,
7.143 Daily 6.30pm. &'11 pm
9,230 Not regular
9,608 Not regular
STATION
CALL SIGN
TIME (HO KON}
67.65 Dobintz (Germany) 6012 Khabarovsk (Russia) 56.7 Nauen
A.F.K.
4,434 Mon, Wed & Fri, 6 j.in. &.2 a, m.
R:197
4,990 610 p.m:
A.G.J.
Moscow
B.F.N.
6.291 Not regular
pin,
Rome
1.M.A
6,806 Sunday midnight
Perth
BAG
41.3
Bingapore
V.8.1.1
7810 Not regular
18.8
Kootwijk (Holland)
1,700 Daily 11 p.m.
37.
Bangkor (Bixm)
32.4
Sydney
31.55 Melbourne
HSARJA 2.BL. 3.1.0.
8,106 Tues. & Fri, 9 pm-1am.
(0,530 | Daily 7 222,
9,020 Fri, 8 ay Eat. 3 am, & 10
Sydney
11. 28.6 27,8
Nairobi
31.28 (Konja)
2.F.C.
9,590 Not regular
8,077 Midnight daily
Bydney
2.M.E.
10,526 Not regular
Bandoeng
PLR
26.68 Cheimilord (England) 5.8.W.
216 Manila
KIXÉ
12,240 Nightly
23.36 Schenectady
W.2.X.O.
18.88 Bandoong
P.L.G,
18.4 Kootwijk (Holland)
P.C.L
10,304 Daily 7.p.m.
17.4 Bandong
P.L.F.
17.280 Daily 8 pm to midnight
TRA
H.8.1.P.J.
17,761 Sundays 2 p., & midnight-
18.3
Kootwijk (Holland) 15.34 Bandong
P.C.K.
18,404 Each afterscon
P.LE.
19,220 Daily 5.30-7 p.m.
16.8 Nancy (France)
12,351 Daily 8 m
13.83 Fittaburg
W.&.IK,
21,540 Not regular
11.020 Midnight-a m. daily
11,761 7.80 þú, & à fim, daily, except
Baturday and Sunday
12,850m, Wod, Fri, Sat.
18,302 Daily 6.30 p.m. to midnight
rain-making radio.
These figures were deduced from!
For Better Result
TRY
MULLARD
BEST BRITISH MAKE
THE
MASTER VALVE
· British & American Bases Available
SINCERE'S
SOLE DISTRIBUTORS
BUY BRITISH & BE PROUD We have just anpacked a Shipment of ALUMINIUM BASE-BOARD & PANELS.
Suitable for Short Wave Receivers and other sets.
that require Screening
&
OTHER RADIO & WIRELESS PARTS (Guaranteed British Made),
observations taken in England. ORIENTAL COMMERCIAL & Co., LTD.
where the intensity of broadenst transmissiong is well above the
overage.
NOT A
A
BANK OF CANTON BUILDING, Trz. 24405.
NOTE IS LOST-
So Perfect are the Reproduction Qualities
If a LOEWE FE 63 9 tube set
is used
REQUIRES FRAME AERIAL ONLY WITH NEW BARIUM TUBES. CAN ALSO BE USED WITH LOEWE SHORT WAVE ÁTTACHMENT.
Demonstration Hours-
-11-11.30
--a‚m»
12.30-1:30 pm
5—5:30 p.m.
WE NOW HAVE IN "STOCK
"Pertrix" High Tension Dry Batteries
100 High
volts and 60 volts.
NEW PARTS, RECEIVING SETS and LOUD SPEAKERS
also arrive within the next few days.
THE
will
CANTON TRADING ASSOCIATION, LTD.
VALL SUHE in, dianuger--UTH" FLOUE
TELEPHONE 24610.