HONG KONG DAILY PRESS, THURSDAY, JULY 24, 1930.
THE
PORTABLE
RADIO
FEATURES
RECEIVER.
·LOCAL POSSIBILITIES OF THE LATEST MODELS.
The power invitations of the local station have not, as yet, encour
[BY COHERER."]
"Advantage of New Valves. The extensive development of agal a very great measure of popu-valve performance fine been the Yarity for the portable radio remain factor in bringing the port- ecivor."
able from a thing to be despised ether amongst the enthusiastic searchers to an instrument holding its own with more elaborate instal
ti
At home, the coming of the sum iner months always heralds further development in designs of this type, and the models for 1939, some of lations while still retaining its
claim to convenience of operation. which are already on the local mar-
accumulator, ket, have reached such a high state The non-spillable of efficiency that even with Hong the increased, volume now obtain Kong's limited transmission powerable from cone loudspeakers, and they should prove quite useful for the lower voltage required for the reception of Z.B.W.
latest valves have also largely add ..ed to the portable's practicability.
This Year's Models, Primarily designed for the pic- nie, the portable is now developing a good deal of popularity as a home set, having the advantages of com- pactness and the surmounting of that greatest of all bug-bears to radio reception, the erection of an aerial and earth
Set for Local Reception. The advantages of this type of receiver to local listeners need not be dwelt apan, and whether it is used out of doors or as a home set, a fortable capable of producing adequate volume from the local station should find a ready market. The essential features of a sit manufacturers have designed their answering this purpose, taking into later models to take power from consideration local conditions and the mains as an alternative to bat allowing for a range of twenty tery supply, and have also made į miles without an additional aerial provision for the connection of are as
With this end in view, many
gramophone pick-up connections and terminals for an extra aerial for those who wish to increase the range of a frame acrial.
EVERYTHING
Batteries (where mains are not available: Two volt non-spiliable accumulator and 190 volt dry bat
tery..
Aerial: 75 feet of 20 guage D.C.C. wire wound round the frame of the cabinet.
I
!!
"QUERY CORNER. "
SHORT WAVE."Your set could be adapted for short waves by making one or two alterations, Your present coil-holder in the aerial circuit will have to be ré-
circuit.
Screen Pictures.
One saw on a screen an image about three inches by two, and al- though it varied in steadiness and definition there is no doubt that both represented an advance on the achievements of a few months ago. There was perfect synchronisation
SOME USEFUL HINTS.
A dirty lead-in tends to spoil dis- cant reception.
+
Valves of the high magnification type generally make good detectors in short wave sets.
*
7
Give your valves the proper grid bins, as failure to do this results in imperfect reception and causes a strain on the H.T. batteries..
•
54
L. F. Transformers and L.F. Chokes should not be placed close together, and the cores should be arranged at right angles to one an other.
*
placed by one of the two pin type, of voice and vision. The proceed disconnecting point on on yourings were no sooner ended than may also be telephone messages of congratula- present helder. It necessary to place a small fixed tion were received from Eendon, condenser in series in the serial where a television set had been in-
stalled, and other outside sources.
One or two alterations have been made since the single-wave trans-
A common cause of "mysterious" missions began. At that time the faults is faulty contact, due to a televisor receiving set and loud-defective or broken flex-lead, speaker were enclosed in the same cabinet, now they are all soparat- ed, the televisor being in a neat gilt-lined cabinet. I was informed that a televisor similar to the one used is now on the market at 25 quiness.
The size of oils for different wave lengths can only be determin- ed by experiment, as they will de- Loud Speaker:-Direct.coupling
of your aerial. to a good make of cone unit driven to a slight extent on the value ing a nine-inch cone.
Tuning:-One condenser dial and reaction control.
Provision for connecting a pick up, screening of high-frequency stages and a turn-table for revolv.) ing the instrument until the aerind is in a position to receive the strongest zignals are also factors to be taken into consideration.
Local Tests.
A set built on these lines (home constructed) was tried out in the open at Repulse Bay recently with excellent resulty, volume being suf 'ficient for intelligible reception of speech at forty feet er more. "The sar set, when tried at a little more"
thin twenty miles from the trans mitting station, gave fairly good loud-speaker results, under sianidar conditions, but with an extret acriul of a few feet of wire at about eight feet from the ground the voluine was greatly increased. It should be
follows. Valves: Two stages of high-frequency amplicorne in mind that this increasing tion (Screen Grid) followed by a leaky rid-detector and two stages of the acrial length of a portable is apt to broaden" tuning, but of low frequengy amplification,
when only the local station is re- transformer coupled.
quired such lack of sensitivity is by no means a disadvantage. The eniployment of a pentode does not prove very successful in such a æt. Used as the only stage of lax-fre
your guaranter
quency following the detector, thus 9.&.C. ELECTRICAL mener following the detectores not give the same volume as two stages of ordinary low-frequency, while, when employed following a detector and a stage of low-frequency, it is apt to overload and cause distor- tion.
TENACIOUS COATING
KEEPS YOUR SET
AT PEAK PERFORMANCE
It's not. the filament but the coating on it that counts
MADE IN ENGLAND
• Sold by all.. Wireless Dealers.
Osram
Valve
Osram Valves
WRITE
with the
TENACIOUS COATING
SRAM÷WIRELESS GUIDE (1879-Edition)-Sent-Post-Free,
A set of short wave coil can be dained quite chiaply from many
local dealers. Your circuit is at the often of the Hong Kong Daily Press if required.-CONERER.
SIGHT AND SOUND
BY RADIO.
THE NEW EXPERIMENT
BROADCASTS.
The new facilities granted by the B.B.C. to the Baird Television Company recently came into opera- tion in London. During the past. few months there have been daily experimental
transmissions of
vision on the single wave-length available, but the granting of a second wavelength, now made pos- sible by the completion of Brook- man'a Park, permits the simul- taneous broadcast of both vision and sound.
A small company, which includ ed Lord Ampthill, chairman of the
Baird Company, Sir Ambrose Flem ing. inventory of the thermionic valve, Mr. Noel Ashbridge, chief engineer of the B.B.C., and Major Gladstone Murray, of the B.B.C was present for the first dual broadcast from the Baird Con- pany's headquarters in Long Acre.
HAVE YOU HEARD THESE?
Here are lista of long-wave 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 depends very largely upon fay- 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.
LONG-WAVE STATIONS.
Wave length
(Metres) Station
960 Manila
- Call.. Kilo
Sign cycle. K.ZI.B.: 1,183 277 Shanghai K.E.M.S. 1,085 280 Tientein C.R.C. 1,070 310 Shanghai, K.R.C. 087 320 Peping C.O.P.K. 943 345 Tokyo J.O.A.K. 870 353 Hiroshima J.O.F.K
850... 355 Hong Kong Z.B.W.. 840 357 Bombay Y.U.B. 840 361 Sapporo
LO.LK. 830 320 Keljo
J.O.D.K. $20 J.O.C.K. 810 370.4 Calcutta. - 7.0.0 909.9 380 Kumamoto, J.O.G.K. 700 JO.H.K '770 J.D.A.K 700 V.U.B. 754 J.O.B.K 750 -C.M.B. K.Z.B.M.
370 Nagoya
*390 Sendai
365 Dairen
399 Rangoon
400 Osakn 410 Canton -413-Manila-
SHORT-WAVE STATIONS...
STATION
CALL SIGN
€7.65 Dobintz (Germany)
60.12 Khabarovsk (Russia)
50.7. Nauer
60, Мовсот
43.5
42
418
38.8
27.
82.6
Rome,
Parth
Singapore
Kootwijk (Holland) Bangkok (Blum)!
Sydney
$1.56 Melbourne
31.48 Schenectady.
A.F.K.
KILO
TIME (Hone Koxe)
OF WORKING
739 726
4,494 Mon., Wed, & Fri., 6 pm. & 2 san. EA07 4,000 8-10 p
A.G.J.
E.F.N.
1.M.A.
6.A.G.
V.6.1.A.B.
6291 Not regular
,000 Tues, Thurs., Sat, 8 pm, 6,896 Sunday midnight
7,142 Daily B
1.p.m, & 11 p.tt, ·
7310 7,780 Daily 11 8,108 Tues. & Fri, 9 pan- at.
230 Not r 9,503 Not regular
P.C.L. HS4PJ. 2.B.L. 3.1.0. W.3.X.L.F. 8,530 Daily
31.20 Eindhoven (Holland) | P.C.J.
31.03 Sydney
31. Nairobi (Kenya)
23.6
Sydney
Bandoeng
25.53
27.8
*.m., Sat, 3 a.m. & 10 am,
0,620 Fri. 3
2.7.C.
8,600 Not regular
7.LO.
9,677 Midnight daily
2.M.E.
10,520 Not regular
PLE
Chelmsford (England) G.S.W.
11,020 Midnight-3 . daily 11,761 7.30 p.m. & Bam, daily, except
Saturday and Sunday
28.30 Seacrectady2,950
13.88 Bandoong
Kootwijk (Holland)
18.4
Bandcong
Bangkok
174
13.0
15,88 Haizen (Holland)
182 Kootwijk (Holland)
15.74 Bandoong
Nancy (France)
2.5.6
13.33 Pittsburg
P.L.G.
16,102 Daily
ite
·630)
0p.m. to midnight P.C.L. 16,804 Daily? p.m. P.LF.
Daily 8 pm, to midnight' TI.6.1.P.J.
PIL
17,280.
17,751 Sunday 7 pm. & midnight 17769 Dilly 10 pm.
2.0.K... 18,104 Dach afternoon P.LE... 19,220 Daily 5,30–7 p.m. 19,301 Daily W.8II. 21,540 | Not regalaz:
Home-Mada Televisors.
It is made by the Baird Com- pany, although the original inten- tron was to leave this branch of the business to outside manufac turers. In addition to the televisor one needs, of course, a receiving set, which is very similar to those in everyday use, slight alterations only being necessary, and a loud- speaker. In a short time it is in-
tended to supply parts from which amateurs may construct their own televisors, though one imagines that technical skill will be needed.
*
Always switch the flaments off before altering your grid bías nega- tive adjustment, especially if you are using a power valve.
#.
Disconnecting the aerial wire from the set, to see whether this has any effect upon interfering noises, is a good rough-and-ready test when it is uncertain whether the interference is atmospheric or due to trouble in the set.
Flat tuning is sometimes due to a leak across a panel, condenser- end, plate, or similar insulating sur | face.
Do not forget that an earthing switch or a lightning arrester
ther, when possible, and should re- should be protected from the wea
For the recent first broadcastceive an occasional overhaul. the speaker or singer sat in front of 4 microphone and television transmitter. The voice was carried along one line, and the vision along another to the B.B. control room at Savoy Hill. There both voice and vision were connected to Brook. man's Park, whence they were. radiated, being picked up at Long
Аста
Mr. Sydney A. Moseley, the "an- nouncer, made a few introductory
T. C. C.
FIXED CONDENSERS
FOR
Accuracy. Dependability and
Long Service
THE WORLD-FAMED RADIO COMPONENTS IN GREEN CASES
OBTAINABLE AT
SINCERE'S
SOLE DISTRIBUTORS
BUY BRITISH & BE PROUD We have just unpacked. a Shipment of ALUMINIUM BASE-BOARD & PANELS. Suitable for Short Wave Receivers and other sots that require Screening. &
OTHER RADIO & WIRELESS PARTS (Guaranteed British Made).
remarks and was followed by Lord ORIENTAL COMMERCIAL & Co., LTD
Ampthilt and Sir A. Fleming, who
briefly congratulated Mr. Baird on his achievement. Then came a con- trast in the shape of popular songs by Miss Gracie Fields and Miss Annie Croft.
TO-DAY'S WIRELESS
PROGRAMME.
BROADCAST »BY_Z.B.W. ̧ON
335 METRES.
12 to 11.30 a.m.-Commercial News. 11.30 am.
to 12.30 p.m.-Chinese programme.
12.30
to 2 p.m.-European pro- gramme of Parlophone records selected and supplied by Messra, The Canton Trading Association
I
6 to 0.30 p.m.-Kiddies' Half Hour, entertained by Auntie Pat Uncles Dick and Jeff. 6.30. to 8. p.m.-European program- me of Parlophone records aclected and supplied by Messrs. The Canton Trading "Association
Lohengrin, Emmy Bottendorf, and
Karin Brenzell (Duct). Sweethearta Holiday-Fox Trot and All That I'm Asking is Sympathy Waltz, Tampa Bine Artistes.
1.
ار
La Source-Ballet Suite, The
Victor Olof Salon Orchestra. The Punch, and. Judy. Show and You're in the Way, Raie "Da Costa (Pianoforte).
Der Rosen Kavalier, Editor-Lor
and Orhem Steadfast and True-March, Par
lephone Military Band. The Parlophone Laughing Record"
No. 2 (The Singing Lesson). Fortissimo, Parlophone Streich
Orchestra. A
BANK OF CANTON BUILDING,
TEL. 24405.
A RADIO with Living Tone
THE
one
LOEWE FE 63
9 tube set
new shipment, just arrived, is one of the most sensitive instruments for long distance and reception with six stages of high frequency.
This set is fitted with new Barium tubes and requires a Frame Aerial only. Can also be used with LOEWE short wave attachment:
Just arrived-New Shipment of" LOEWE R533 A.C. SETS.
Mickey Mouse Fox Trot and 8126 without Loud Speaker. $150 with Loud Speaker.
and March of the Chocolate Soldiers-Fex Trot, Arthur Rosebery's Band
Andalusisebo Serenade and Lie- besstandcher, Edith Lorand Orchestra,
Dance of the Raindrops Fox Tret and Vamp of Baghdad- Fox Trot, Arthur Rosebery's Band.
Sprich Nicht Non Ewiger Liebe
and Unter Doro Lindenbau Emin Betzenderi (SopraHOUT A Wie Sichst Du Asia and Parfum,.
Saxophon Orchestra Deburi.
Der Liebeswalzer, Emmy Betten-
dori (Soprano).
8 p.m.-Chinese programme...
Sp.m.-Weather report..
9.01 p.m.-Chincas programme con-
tinued.
10.30 p.m.-Close down.
Demonstration Hours.
11-11.30 am. 12.30-1.30 p.m. 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.
TELEPHONE 24610.