1924-01-26 — Page 14

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SATURDAY JANUARY

RADIO NOTES AND

How To Clean “Sulphated" Accumulators.

FOR EXTREME CASES, This was followed again by thorough washing with water, as before, to remove all sediment. The battery was now clear of sulphate, and after washing out with some new soid of charging strength, was filled up with now electrolyte and immediately put to the charging board in the usual way.

Wireless- experimenters who agitated again until the platos, have: neglected their equipment { were free of sulphate.. during the summer months may now find that one of their a cumulators refuses to take or hold ja charge says a writer în Popular Wireless. On examination it will be found that the plates of the faulty battery are more or less coated by a white or grey deposit of sulphate of lead. The trouble is generally, worst at the upper ends of the plates, at the acid level, where the "sulphating" In very bad cases of sulphating may be so extensive as to form it may be found that this treat- short circuit between the platos.ment causes part of the plate The only way to prevent "sul-fillings to break off after removal phating" of accumulators is to of the sulphate. This is not düze keep them constantly in use with directly to the action of the nitric regular changing and discharging- acid, but due to corrosion of the Even when an accumulator is plates during the sulphating. In laid aside with full charge, this such cases the celluloid cover {gradually leaks away, and as should be opened in the

soon as the battery is almost rua jusual, way, and the plates) dowa local action commences. removed to get tid of The electrolyte, dilute sulphate any coarse particles liable to acid, attacks the plates, forming produce shorts. the lead sulphate, which is one of If the outer surfaces of the most insolable substances plates which are not protected or known to the chemist.

supported by the celluloid separa. The usual treatment frequently tors show much sign of corro recommended for clearing up asion or disintegration, some glass sulphated accumulator is alter-wool should be inserted around nate reversal of current direct-same when replacing them in tion in charging. It has also the case, which is then sealed up been suggested that good results with celluloid cement. may follow a temporary replace-NEW TELEPHONY TRANSMITTER. ment of the arid electrolyte by. It is a well-known fact that, in strong soda solution during the order to transmit speech by wire- alternation of current reversal less, the radio transmitter must Such remedies may be effective produce waves which are un- with a very slightly sulphated damped, or what is more com battery. but I have not found monly known as. C.W. The sys- them successful.

tem used for producing the waves are andamped, or what is more (commonly known as C.W. The system used for producing these wares by most experimenters is the thermignię valve.

the

DIPOSSIBLE TO DISSOLVE.

A much more efficient method is to open the case, remove the plates, and carefully scrape off [the offending sulphate by means of a knife and a wire brush. This fuperation is not only tedious and jiroublesome, but not always an

unqualified success..

There Are many wireless amateurs, however, who, although familiar with the quenched park į system for spark transmitting, Obviously the most satisfactory are not aware that this type of method of removing the offending spark gap in the correct circuit sulphate would be to dissolve it will give continuous wave trans- by some simple solvent. Unfort- mission, and can therefore be used unately this cannot be done. A for telephony. This system; hot, strong solution of ammonium | which was invented by Dr. E. L. acetate has a solvent action on Chaffer. some years ago, pos- lead sulphate. It is also slightly sesses many advantages from isolable in a strong solution of the experimenter's point of ammonium tartrate. These solu-view, as it is easily and cheaply: tions may be tried in the case of constructed, and is particularly a slightly sulphated battery, suited for low-power transmis- where the plates have only asion. slight film of the sulphate.

The circuit required for this The writer has had from time type of transmitter is extremely to time many sulphated accumu-simple and differs slighty from lators brought to his laboratory the ordinary quenched gap for treatment, and, after numer-circuit which is used for spark ous experiments, found that the transmission. This transmitter only satisfactory method of re- is composed of three circuits.| moving the sulphate chemically which are as followes: the. lay in the use of solvent that a direct current or primary circuit, tacked the lead plates themselves, the closed oscillatory circuit, and thus loosened the coating of and the aerial circuit. [sulphate. A badly sulphated Tue primary circuit consists accumulator which had been out of the 300-volt high-tension of use for over a yeare and which supply, which can either be com- | absolutely refused to charge, was posed of a battery small genera- treated by this method success-tor or the house lighting supply. fully, and the first charge after The variable resistance and the treatment gave a reading of five iron core inductance are included volts for the two cells after a in this circuit in order to regulate normal period of charging. the strength of the supply

|current.

HOW IT IS DONE.

The following details of this

The variable, condenser which method indicate how a badly sulis in both primary and closed phated

oscillatory circuits, must bel accumulator may be

made with mica or "ebonite

cleaned up

The old acid was poured out of separators between the plates, the battery, which WAS

then

sary in both primary and second-

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While some of the birds took readily to the microphone, others had to be coaxed into singing\by soft tones of a violin.

L.C.C. TRAMS.

in order to prevent any sparking be clamped to a rubber washer. WTAM, the all-storage battery washed out with water, inverted, which is likely to occur, owing The construction of the spring station here.

Those who listened in heard and allowed to drain for a few to the high voltages used. This diaphragm and holder depend

upon each other. If the holder is the best canary voices in" the minutes. The cells were then condenser is. 005 mfd, max. half filled with nitric acid (pre- THE QUENCHED GAP.

composed of metal, it will be land. Fonter Premier,” jud- necessary to use for this iged the world's champion singer, pared by diluting the strongest

The remaining portions of the concentrated aitric acid with an closed oscillatory circuit are the diaphragm a mice disc, such as led the programme. Another are sold for gramophone sound-artist was ""Lohengrin,” · 1922 equal volume of water), plugged, quenched gap and the primary boxes.. If, however, the holder champion, which has been made and agitated so that the nitric coirof the oscillation transform is made of some insulating a gift to Mrs Coolidge was kept in active movement over er. The number of turns neces material, a metal diaphragın can the plates

In a few minutes the bulk of ary of this transformer will de-be used.

Having constructed the set, it the sulphate was detached from pend upon the wavelength used will be found that a few adjust the plates in the form of a grey and the size of the serial sediment. The nitric acid then The microphone is connected ments are required in order to

obtain an undamped wave. was emptied out into a glass in the earth lead of the open obtain this continuous wave vessel, in which a considerable circuit, and on account of this it amount of sulphate settled to the will be necessary for the instru-transmission it is essential that the spark frequency be exactly

The loss on the year's working bottom. The clear acid, after a ment used to be of sufficient size one-half, one-third, or one-quart of the London County Council few moments settling, was then to carry about one ampere, and iter of the oscillation frequency, trams is expected to be about poured off into another vessel for will be found that practically Since the spark frequency de £100,000. This can be easily met

ordinary -low-resistance A small committee of experts, which has just finished its work further use. During the settlingany

carry

pends upon the strength of the out of reserve. Much higher summoned by the League, dis-at Geneva has drawn up conven- of the sediment from the acid, microphone will

supply current the required estimates have been made, for the There is a proposal afoot for cussed the proposal recently at tione dealing with the tranmis the accumulator was repeatedly amount of current. League of Nations Conference Geneva and recommended that sion of electric power across half filled with water, plugged. The most important portion of adjustment can be obtained by trams find greater competition altering the variable resistance than ever in the omnibuses. The to organise a national system such a conference be called to several countries and with the thoroughly agitated, and em- this type of transmitter is the and the oscillation frequency maximum tram fare is to be re- of listening in says a London gether about the middle of 1924. development of hydraulic power ptied.

The conference would be partici-on international rivers.

duced from 6d. to 5d, and returne tickets are to be issued The recent developments in pated in by private firms as well

HOARDINGS THAT MAR LANDSCAPES wireless, whereby, for instance, as by governments and would distepers-in in this country can draw up a code of regulations

"A definite move in con bear Presiden: Coolidge making affecting wireless telephony and a speech in Philadelphia and the broadcasting, as well as wireless probable developments in the telegraphy. near future suggested by the

INTERNATIONAL RULES

PROPOSED.

comment.

MOST IMMORAL COUNTY.

quenched gap.

that

condenser.

Each wash of water brought The two electrodes must be can be controlled by the variable out considerable quantities of composed of copper, and these

A fairly tight coupling should load sulphate, accompanied by a should have a surface area of be used between the serial,coil very slight brown deposit of approximately 3g in each, and

and closed circuit coil, as this is peroxide. At least half a dozen should be separated from found to improve the quenching with the campaign Banffshire, according to Sheriff washes with water in this way each other, by about 03

of the gap More, has the worst record of any should be given, or more any One electrode is threaded so that At present there is no interna-county for immorality. Thirty loose sediment of sulphate re-it can be screwed in or out of the present researches into the potional scheme regulating wireless one cases of the kind have been mains. The accumulator was holder for adjust sibility of seeing by wire services, and the League proposal tried in Banff Sheriff Court within not quite free from sulphate The Meas, are responsible for the will no doubt meet with general a year. The Sheriff said there after this, so after draining the moun

hey seemed to be no public opinion în acid, which had been once used phra anitiative now being taken by the approval.

League of Nates for drawing up Appropriately enough, the Les- the matter, and either the law and settled clear of sedi International piles and regula-gue's Second General Conference was not known or it was laughed was returned once more

on Communications and Transit at

CÁKARIZS BRO.

disgurament of [countryside.