Wireless Magazine, August, 1932 THE TRIPLE -TUNE FOUR ...

[Pages:104]Wireless Magazine, August, 1932

THE TRIPLE -TUNE FOUR Continued

TUNING

DETECTOR

large primaries give the best signal

strength. Those who live a fair distance from the nearest broad-

casting station will probably seldom have to use the small primaries, but

for those in close proximity to a broadcasting station the small pri-

maries will be invaluable.

Suitable Valves

Any standard types of screen -grid

valve will be suitable for the Triple tune Four. The detector should be

of moderately high impedance, say

of the order of 20,000 to 25,000 ohms.

The power valve will, of course,

have to be chosen with an eye on the

limits of the high-tension supply. If

VOLUME

ON -OFF SWITCH

a mains unit is used for obtaining high tension then the power valve

CONTROL

can be of much lower impedance

THRZ.F. TONING CONTROLS-BUT NO REACTION

than would be economical if dry

Although the Triple -tune Four has three tuning controls it is not at all difficult to operate. There is no reaction knob to complicate the adjustment

batteries are to be used. This is a point for the individual operator to

is switched off the potentiometer scores of stations at good strength decide for himself.

knob should therefore be turned from all over Europe.

Once more we repeat that only

right round to the left.

There is not much more to be about 2,000 sets of coils for the

Results on Test

said about the set. The method of Triple -tune Four are available. tuning will be clear from the remarks When they have been disposed of

The test report on page 76 may made in the test report and from they will not be repeated.

not seem very impressive for a four- what has already been said in this We are certain that they will be

valver with two screen -grid stages, article. Operators should try the satisfied with the results that can be

but it must be remembered that the alternative primary coils which, by obtained from this receiver and we

test was made in the middle of the the way, are plugged on the sides of anticipate that in a few weeks we

summer when reception conditions the main coils.

shall receive many enthusiastic re-

were at their worst. In the autumn Remember that the small primaries ports on the performance of the

this set will be capable of bringing in give the best selectivity and that the Triple -tune Four.

The B.B.C. Flag

MOST people passing by Broad- ling the earth.

casting House in Portland This unique flag

Place notice the B.B.C.'s flag flying is hoisted every

from the top of the building. This morning at 9 a.m.

flag symbolises broadcasting by a and is low,:red at

very appropriate design.

6 p.m. There is a

It may interest listeners to know smaller edition of the

that the flag is based on the B.B.C.'s flag for use on stormy

coat of arms.

or very windy days.

Earth and Ether

The flag flys over what most people

Made by Mr. G. P. Jennings, the would think is the

flag consists of a terrestrial globe, bow of the " ship "

representing the earth, on an azure called Broadcasting

field, representing the ether. Around House, but we now

the globe are seven planets.

think of this end a;

Pluto, the new planet, is not the stern, because of

shown, as this was not recognised as a course the ship's flag

major planet at the time when the always flies above the

original coat of arms was designed. " Admiral's " quart-

Encircling the globe is a golden ers. Sir John Reith

ring, symbolising transmissions gird- is just below.

78

THE B.B.C. FLAG Lheoanddqonuarertaedresrsowf tihllebeBa.Bbl.eCt.oasteBe rthoiasdfclaagstfilnygingHoovuesrethine

Portland Place Regent Street

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