HONG KONG DAILY PRESS, THURSDAY, JULY 30, 1931.
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HAVE YOU HEARD THESE?
Here are lots 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 fav ourable atmosphèria conditions. Renders 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.
WAYS length
830
FEATURES
GOOD SHORT-WAVE AND
BROADCAST RECEIVER
THE NATIONAL "S.W." A.C. THRILL BOX: GIVES HUMLESS
RECEPTION.
B.B.C.'S GIANT NEW BEHIND THE SCENES AT A
MUSICAL SHOW, HOME.
CENTRAL TOWER OF STUDIOS.
Wireless performers, according to Mr. M. T. Tudebery, the B.B.0, Civil Engineer, may have to bo
Realizing that before short-wave short-wave receiver in which the is done to eliminate troubles from prepared to exercise a little for receivers could come into popular hum ia as low na in a battery power-so-called modulation hum..
480 they must be made toed set.
operate with the same case and First, the valves themselves must
The Tuning Circuitz/ Unit. convenience as a modern broadcast not only be of the heater type, but receiver. A receiver was need also, for complete freedom from
The unit comprises one pair of ed that would not only hold its hum, must be carefully selected. the R-30 plug in type coils and two own against any of the older type This is especially true of the detec of the new tuning condensers gung battery operated sets for general tor valve which may be found tong by Nation, type II drum amateur, and experimental recep- ho quite noisy when just on the tion, but would also meet every edge of oscillation, unless it is dial. The plug in coils are moulded requirement of the non-technical selected with care.
of R-39, the well-known low-loss owner who, when he felt so inclin- ed, wanted to hear GSSW, Cheims The cause of hums when using coil form material resently deve ford, England, 30 in Melbourne,
some types of heater valves is
bearance in the matter of damp walls when Broadcasting House, in Portland place, is in full working next spring.
The giant tower of studios which forms the core of the building if artificially ventilated, and the three-foot-thick wall which
which sepa
rates it from the outer offices at
ed"
(Continued from Page 1.)
again," says one pretty blonde, and on they troop putting smiles and animation into an ingenious tune to the words:
Just stand up and sing, You'll never do wrong, etc." And it struck mo that whatever words any girl sang, she could never do wrong. For if the words of musical-comedy choruses are only semi-intelligible from the front, they are utterly unintelligible from the wings. Perhaps it is as well.
The song is ended. The melody does not linger on. A litho figure
present contains many tons of water in
in grey suit I notice standing front of a contraption of which must gradually be sweat handles, brass plates, and mystic
out over a period of months.
inscriptions, prominent among "Although the heating and them being "Stand By, Randy, Go, Australia, or any one of a dozen apparently due to two things; one loped by the Radio Frequency ventilating apparatus an
is the most Flies, Audit, Lts., Gallery, Fly being direct leakage across the Laboratories for short-wave use. complete and efficient possible" P.S." It is Mr. Jack Buchanan. other foreign broadcasting stations coramic insulating column between They are specially made to fit 6-Mr. Tudsbery told a representa. He is supremely at ease. So would without the necessity of waiting one side of the heater and the prong socket, which permit, com- tive of The Daily Telegraph recent I be in his shoes, since all round me: for possible re-broadcasts of the cathode, and the other to an un neutralized 60 cycle field around the
stations.
As a result of this survey, the following essentials of a good short.. wave receiver were brought to | light-
1-Absolutely humless d.c. opera-
tion..
2.-Single dial control. 3-Loudspeaker reception
foreign broadcast stations. 4.-Good tone quality."
5.Non-critical tuning..
6.----Neat appearance.
plete independence of the three, it is not, unfortunately, adapted to the drying-out process windings which appear on each coil which must take place at first. In general, the 227 valves, when form. This independence permits
"For some time conditions in the
heater.
is sechery labelled "The property
of Jack Buchanan.'”.
Mr. Buchanan trota casily on to the stage and there is a roar of
operated on the verge of oscil | two major advantages. One is studios will not be at their, best, welcome. The clown in the old timo
lation, are less troublesome than
When they reach normal the at pantomime used to say, "Here we the 924 valves. At first it was
avoidance of detector grid-blocking mosphere inside the tower, for are again! Mr. Buchanan uses thought this quieter perfor. and the other is the satisfactory purity, temperature, and freshness,
a modern variant. He says, "Good fromance of the 227 would tend ganging arrangements. The new will actually be better than that
morning, everybody." Immense laughter. Lucky Mr. Jack Bucha nan! Yet it is not really luck be-- yond the Juck of possessing a per- sonality the public adore,
to recommend its use as the detec
tor. It was soon found, however, taning condenser has been designed of the outside offices, with windows
on the street,”. that, though more noisy when ap- especially for thort-wave work and proaching oscillation, the 2 screen is not of the cut down" broadenst
Gut Colling.
Sudden darkness Cimmerian.
Now, we have learned that after Brid detector, as, under practical | variety. Among the outstanding All the studios, including the Impenetrable. They call it a many years of research work on the conditions, actually quieter due to features is the use of the 270 deg. great concert hall, it is hoped, will -
development of mich a receiver in its improved sensitivity, eliminat- the laboratories of the National ing the necessity for full regenera- Company, Malden, Mass, U.S.A., tion for the same signal output as in collaboration with a number of obtained with the 227. Improved well-known short-wave authorities, tone quality was a further by-pro
rotation equicycle plates, insulated front bearing, constant impedance pigtail, single hole panel mounting,
be working by the end of the your A large number of the outer offices are already completed and decorat ed, and tenders for decorating
black out," and it is. Soft-shoed
stage-hands say Mind your back, plekso," in stage-band whisperers.
Hard-headed stage-managers
BOY,
* Don't worry me now, d--
a new all mains short-wave receiver. duct obtained from this decreased as well as provision for baseboard some of the studio suites will short on Huge walls of scenery are.
known as the National "S.W. A.C. Thrill Box, has been develop ed.
The Circuit,
amount of regeneration.
Power Supply.
mounting, inch shaft and R-39 lowly be invited in limited competition. loss insulation.
The B.B.C. secretariat is expected to "move in" in the autumn
The second point that must be
Operating Notes. given careful consideration if The circuit of this short wave successful .c. operation is to be
Owing to the sensitivity of the receiver itself comprises a tuned had, is the power supply unit. 224 screen grid tube, the tuned. screen-grid radio-frequency stage; & This unit should be entirely radio frequency is inther broad, screen-grid regenerative detector; a separate from the receiver itself, unless a very short aerial is used, Call Kilo- (Metres) Station Sign cyoletwa stage transformer-coupled audio completely shielded and located at
260 Manila KZI.B.: 1,153 amplifier, employing push-pull in least three feet from the receiver The trimmer condenser located on 277 Shanghai K.S.M.B. 1,093
the second stage and with provision proper.
the right hand side, of the cabinet", 345 Tokyo J.O.A.K. 870
for plugging phones into the output The outstanding feature of the serves to compensate for various 333 Hiroshima / J.O.F.K.
of the first audio stage when de power supply especially made for 355 Hong Kong' 2.B.W." 846 sired; and a separate power pack this short-wave set is its exceed lengths of aerial that may be 357.1 Bombay V.U.B; 840 especially designed for short-waveingly low inherent, hum. in its out used, and need be set but once, 361 Sapporo J.O.LK,
work. -830
put, by employing a double section when the receiver is first put in 388 Keijo J.O.D.K.890 The circuit as it appears is quite filter using good quality chokes and operation. As it affects the opera- 370 Nagoya J.0.0.K. 810 conventional in every way. When 370.4 Calcutta
plently of condenser capacity. The tion of the detector stage, it should V.U.C. 800.9
dealing with short waves, it is not power transformer has an electro-be adjusted and then forgotten, in so much the circuit which counts, static shield between the primary order that the stations may be but the manner in which the circuit and the other windings in order to logged accurately." is used. Little things, like the 788
prevent line disturbance from get The aligning procedure is simple: order in which the valve heatersting into the power unit and into the detector is put just under the ace wired, the insulation of the the set,
* edge, of oscillation and the trimmer bearings of the variable condenacrs. This set is completely enclosed condenser turned until a point is the type of materials used in the in a steel cabinet in order to ex found where oscillation is maximum. coil forms, and so on without end clude stray low-frequency magnetic Of course, the detector may still he is what makes the difference be fields. Incidentally, these strays made to stop oscillation control. tween successful design and one fields seem to be the cause of the This method of aligning is much a.chum frequently encountered more accurate than the usual Hum Eliminated
with some battery operated short-custom of tuning in a station for Opensionally good hum-free A.Ç. wave receivers. To make the shield- maximum volume. operation on short waves may being more effective, the power supply Having a good receiver in good obtained by the mere substitution potentiometer with its by-pass con- operating condition is only half the
350 Kumamoto J.O.G.K." 700 300 Sendai J.0.H.K. 70: 395 Dairea J.Q.A.K 760 400 Osaka: J.O.BE 780 410 Canton C.M.B. <80 Manila K.Z.R.M. 028
SHORT-WAVE STATIONS,
RTATION
CALL 8102
67.66 Doblaty (Germany)
TIM (Bono Koxe). OF WORKING
4,434 Mon., Wed, & Fri., 16 p.m. & 3 am which is a failure. .4,000) 8-10pm.
A.F.K.
30.12. Khabarovak (Russia) [RA.97.
35.7
Naudiów
'AGS:
**8,201-} Not regular
B.F.N.
6000 Tues, Thurs, Bat, 8 p.m.
50.
43.5
Bome
LM.A
6,896 Sunday midnight
Parth
6.A.G..
7,143 Daily 5.80 p.m. 11 p.m.
41.8
Singapore
V.8.1.A.B.
7,810 Not regular
B848
Kootwijk (Holland)
P.C.L..
4,780 Daily 1 pm.
37.
Bangkok (Big)
88.5
31.55
dhome
TSLPJ 2.B.L. 8.1.0. W.2.XA.F.
8.108 Tues, Fri, 0 pm-1a.m.
0,230 Not regular
ZE.C
81.48 Schenectady
81,20
Eindhoven (Holland) [P.C.J.
81.28 Sydney
|1.LO:
0,609 Not regular ride
9,830 Dally 7. MAT
9,620 Fri, 3 Am., Bat. 8 am, & 10 x.m.
9,690 Nob regulie
9,677 Midnight dally
10,620 Not regular 2.M.E,
P.L R
Secure England) 0.8.W.
W.2.1.0.
81.
Nairobi (Kenya)
28.5
Sydney
27.8
Bandoeng
20.69
KLIE
28.85 Bohenectady
18.85 Bandoong
P.LO.
18. Kootwijk (Holland)
P.C.L
17.4 Bandoong
10.9 Bangkok
108 Kootwijk (Holland)
16.74 Bandoent
15.3 38.98
alrurg
PLF HELPI PCK Pole E
WALK
11,030
11,761/night-8 am, daily ́
7.80 pan. & 2 am, dally, except
Saterday and Sunday
12,240 Nightly
13,350 m. Wod, Fri., Bat. 16,102: Daily 6.30 pm, to midnight 16,504 Thily 7 pani 2014 ma -17 290 Daily 8 pm to midnight 17,781 | Bundays 7 p., & midnight 18,404 Bach adenoon"
| 18,230 | Daily £60. pmi
18751|| Dilly 8km/
21,500). Not regular
ewe boer ahead of true time.
1
of the heater type a.c. valves for densers aro both located: inside the battle. You have to know when 'to- the more conventional d.e. types in set, in order to eliminate any exlisten, and at whatip points. on the
stations shown in this page with their hours of operation in local time, should be of great assistance. to you in this respect,
a standard battery operated short-ternal Isade which might contain diale. The accompanying list of wave circuit, In most cases the radio-frequendy currents
And now comes a method of humn mero use of conventional quick- heater type a.c, valves results in a control that will perhaps sean more quite pronounced and annoying tum logical than those already describ- that tends to vary somewhat on tifeed; that is the location and ur different short-wave bands.
rangement of the wiring. In the
After considerable experimenting, National BWs Thrill Box, the re- it was found that there were some ceiver is constructed on a metal dozen or so very definits sources sub panel, to which is also added a of hum trouble to be encountered in metal bottom shield. By being the short-wave receiver that would careful to aco that practically all not cause the slightest troublé in of the radio frequency leads are
brandcast receiverinaldizaynthe flock
sak nagelnwhile identification and the-chuination all of the power supply lends are of these concealed sources of ham located in the
compart- that finally made possible an a.c. ment beneath the sub-panel, much
Coll Tuning Ranges. Black (No. 11) Range 14 to 25
meters.. "Red" (No. 12) Range 23 to 41
meters.
White (No.33) Range 38 toll
70 meters.. Green
No. 14) Range 55 to 115 meters. Orange" (No. 18) Range 200 to
300 meters
So far the building has construct
ed almost exclusively of British materials and by British workman ship.
sliding easily into position. Cloths ascend and descend from the "dies," as if the gods in Valhalla were having a washing-day
stout sallow gentleman of Turkish aspect, wearing a prenos terous little Harrow stray-bat, re-
Hopton Wood stone, with a gilt aised Mr. Morris Harvey, My The entrance hall, designed in acues me I would not have recog
ceiling, has just been completed. fourteenth different hat this week, "We are very satisfied with the he says, "they are coming in from progress made," Mr. Tudsbery said. all over the world.?! "Work at present is actually ahead of schedule, and, as far as we can see, we shall have kept the cost to practically the originally - esti- mates," "
So we ascend to his dressing- room.
W
A spot!"
"Undoubtedly,
Thus is the ntago ritual complete. " Undoubtedly.",
SHORT WAVE RECEPTION Use A
NATIONAL “SW 5” THRILL BOX
ALL MAINS RECEIVER
Range 14-550 Meters
"AO MODEL
TY 24
DO MODEL
239
1-CA 230
3UY 227 1--UX 280
2 RCA 281
Matched Tubes
Complete Kit for both models are available.
'Inspection and Enquiries are
Always: Welcome,
THE WING ON CO LTD
Yellow''-(No.-17) Range 350 tolle Tatr
650 meters,
Sole Distribut