THIS YEAR'S RADIO

Radio Record, Volume IV, Issue 44, 15 May 1931, Page 9

THIS YEAR'S RADIO

A Review of the Radio Receivers and Equipment that will be available in N.Z. during the Coming Season

Majestic

-_ HIS . season’s. Majestics incorporate many features hitherto not generally seen in New Zealand. The introduction automatic volume control» minimises ading and keeps volume at a constant level, while a still finer degree of selectivity has been introduced without sacri-. fice to tone. "Multi-Mu" s.g. valves are used in the new sét and eliminate much background noise, cross talk, modulation distortion and valve hiss. They are equipped with. uniform -calibration full vision dials, so that tuning can be made easier. A double knob just below this includes the ‘tuning knob and a larger disc ‘which is the volume setter. An acoustic control, to regulate bass and treble and at the same time cut out a fair proportion of static, is also included, All the new sets are super-heterodyne. Model 21, although it looks a midget, has the power of the full set. It is adirably constructed and capable of really good results. It is equipped with a standard 8-valve chassis. Model 61 incorporates all the new fea~ tures and uses a 9-valve super-heterodyne circuit. | Gramophone combinations are also available. The Auckland agents are Lewis Eadie, Ltd. Pilot Products

prot radio parts need no introduc-tion-their name is legion among tadio- constructors. Every few weeks

sees the introduction of some new, and up-to-date component. Pilot market two receivers in this country, the Consolette and the Midget. The Consolette is a small set 33in. high, housed in a Queen Anne Cabinet. It is provided with tone and volume controls, th latter operating on the screen-grid valve and tuning knob. Six valves are employed, three 224 type, one 227 type, and one 245 type and, of course, the rectifier. All these are Pilot’s own manufacture. ‘ The Midget is only 17in. high, -but uses the same chassis and loudspeaker as thé Consollette, with all the same features, including tone control. Gulbransen

GULBRAN SENS make several models, the best known being the Champion, the Champion Lowboy and_ the Minuet. The Champion stands 4 feet high, and is housed in a console cabinet finished in American and Oriental veneers. Three screen-grid valves, two of the 227 type and two of the 245 type, in push-pull, are connected up in a straight circuit. The set is provided with tone control, volume control, which operates on the coupling and on the screen-grid voltage, and a local and distant switch. The Champion Lowboy is built of the same material and is as carefully inspected as the Champion, but its size and power are slightly less. Three screengrid valves, one 227 with two 245 type in push-pull are the valves: used. This set stands 40in, high. The Minuet is a large radio receiver in a compact form, It is light enough

to be moved from room to room, and serves as an end table when drawn alongside an: armchair. It embodies all the features found in the larger models. The circuit is the same as the Champion Lowboy, and the size in no way ‘means cramping of parts. The Auckland representatives are: Caddells Ltd., Queen’s Arcade, Queens Street, Auckland, and R. W. Strong Ltd., Queen Street, Auckland. Add-a-Phone

HE Add-a-phone is not a shortwave adapter, although it may be used as such, for it may be used in a separate set or coupled to either ac. or d.c. receiver. It is a remarkable set developed after years of intensive study of shortwaves. In view of its being shielded in metal it can be used in cities where interference is bad, while tuning dials of the direct drive type and alternatively 300-1 ratio, insure smooth control with no blacklash. It. will oscillate below 20 metres with .8 volts on the filaments of the 230 types of valves. The Add-a-phone can be connected ‘to a set and the phones kept on at the same time. It is an all New Zealand product, and nowhere is there a set even remotely resembling the Add-a-phone. Pam Amplifiers

PROBABLY the best known amplifiers in America to-day are the Pam, and these have already made their appearance

in New Zealand. This year the New Zealand agents, Messrs. J. A. Smythe and Co., of Wellington, are importing the new and improved amplifiers. Greater compactness, improved appearance, less weight, longer life and lower hum voltages are some of the features claimed © for this new series. Uniform amplication has resulted in a new brilliance of tone. There are three models, 29, 39 and 59. The 59 is the smallest, and delivers an undistorted output of just over 43 watts. It has two stages of screen-grid, one 250 and one 281. The largest is the 29, as before with two stages of screen-grid, but this time 224’s, followed by four 250’s in push-pull and four 428’s. This amplifier has an undistorted output of 18.6 watts, with an average gain of 65 decimals over the entire scale..-The net weight of this huge amplifier isanly 60lb. It is complete with line voltage, compensating plug and fuse. Pam antplifiers are to be found in many ofthe big ballrooms, and on many of the. béaches, sports and showgrounds in America. Radiola

THIS season Amalgamated Wireless are featuring the new Fisk Series Radiola 45E. This is an all-British receiver, the products of the AWA. factory in Australia, The circuit employs three screen-grid tuned stages, a screengrid power detector, and a 245 output stage. The tuning control is calibrated in metres for quick and precise station location. The volwme control varies the screen-grid voltage, while the set is provided with a local and distant switch. The voltage regulator, to enable the transformer to be adjusted to suit the main, is a safeguard on valves and cofdensers. The chassis is provided with a gramophone and loud-speaker jacks and 240-volt outlet socket for supplying current to. the gramophone ‘motor, a distinctive and altogether new innovation,

Radio-phone change-over switch is provided at the front of the cabinet. The set stands 37in. high, and the cabinet is specially constructed of wellfinished walnut in deep brown. In the. Auckland district the receiver is handled by the Farmers’ Trading Co. _-. Ultimate Radio FOR years the. pioneers of Ultimate «radio were convinced of the value of ead theanroh their exnerience in supplving

lightho u ses with short wave radio equipment. In the second year of production ‘about 100 receivers were sold in New Zealand. The third year brought a definite realisation to the radio" prospect that short wave reception had been

established as a means of entertainment and amtisement, with the result that about 500 receivers were’ sold. This year has demonstrated ° the fact that short wave reception is no longer a freak, and that it is as easy to receive the stations on the other side of the world as it, is to tune in the nearer broadcast stations. The new Ultimates are ac. operated and give speaker reception of these sta-

tions; furthermore, it is a British product. It appears that one of the features of the 1931 sets will, be the ability to receive short wave transmission from the most distant portions of the globe. The latest Ultimates are being shown at the Auckland. exhibition ‘by ‘the Farmers’ Trading Co. stands, who will be’ pleased to demonstrate or give. further. particu- ; Crosley —

ROSLEY has come forward with several new models. Worthy of note are the new cabinets which employ Crosley repwood, a new and exclusive material which enables the employment of new methods of construction and © ena 2 on a -_

zreatly improves the acoustic properties of the cabinet. The Crosley. Widget incorporates three screen-grid valves and the usual tuning and tone control arrangements. It is only 124 inches high. The Buddyboy is the larger model, being 154 inches high, and employs a new, highly efficient circuit, utilising three stages of screengrid. It is equipped with an all in-built . aerial and ground systems of flexible ma- | terial not much thicker than a visiting card. This is fitted into the top of the set-an entirely new and different devel-_ epment in radio which is exclusive to Crosley. It eliminates the aerial and ground in bringing in the local station. The. Crosley Classmate is a still larger set using two screen-grid valves. The Director is the largest set of the series, and it incorporates automatic _ volume control, It uses 7 valves in ‘all, two screen-grid in the radio frequency, screen grid detector, 227 as first audio, and two 245’s in pushpull, with a 280 réctifier The North Island agents are Abel Smeeton, Ltd., Auckland, and the South Island «agents are Messrs L. B. Scott, Ltd., Christchurch. Standard Telephones and Cables N important phase in the activities of Standard Telephones and Cables is undoubtedly the provision of radio telephone and telegraphic links for connecting the telephones and_ telegraphic systems of different countries. -Equipment consisting of 200 kw. longwave transmitters and 60 k.w. shortwave transmitters, through which the King, iva |

n London, was able to talk with the} Prince of Wales in Santiago, was manu-Ay actured by S.T.C. Another 20 kilowatts shortwave equip nent at Rugby is used for commercial ‘adio. and telephone service, Other standurd radio transmitters are in operation or in the course of erection at Madrid, Buenos Aires, Bogota, Lima, Rio ° de Janeiro, Santiago; and ‘Canary Islands Radio telephone broadcast équipments are used in. Sweden, Italy, Denmark, Poland, Spain, Firiland, Czecho-Slovakia, Switzerland, Japan, China, South ‘Africa, Australia and New Zealand. Lyratone ee ae

"THE Lyratone is a product of Gilfillian Brothers, one of the . pioneers . of American radio. "It is a midget receiver that has already become firmly established on the New Zealand market. The features of the set are a Lansing dynamic

speaker, four screen-grid a.c.. valves, one 227 and one. 245, with a 280 rectifier, four tuned circuits. for selectivity, ' tone control, compact-it is only 22 pounds, and stands 14 inches, and requires no aerial on the local stations. Although small, it losés nothing when results are to be obtained. The Lyratone combination is also a midget, for it is only 19 inches in height ‘and 15.inches wide. It is a five-valve set utilising three screen stages. The gramophone, which is made accessible by removing the top of the set, is of the induction type, and is provided with a volume control and automatic stop. The "Bantam" midget set will also be introduced this season by Messrs. Crawford and Finlayson, who are handling the Lyratone. This is a superheterodyne -valve set utilising three -screen-grid valves, two 227 type and one 245 type ‘valve. It is a wonderful companion with a wonderful range. Colonial

v~~ HE Colonial Princess is a full-size console model, .employing three screen-grid valves with a double preselector circuit in front of the first. The over-all sensitivity of the set is better than 5 micro-volts per metre on antenna height. When recently testing this set with an improvised aerial it brought in several American stations at good volume. As far as selectivity is concerned it is claimed that it will eliminate 2FC and 4QG, Brisbane, when operated quite close to Z2YA, and when near 1YA, 2BL and TOAK can be brought in. The volume control operates on a new principle, which makes for distortionless reproduction; even when throttling a powerful local the tone is faithfully maintained. Maximum sensitivity over the whole scale is obtained by an arrangement which automatically increases the coupling as the dial is turned towards lowe frequencies, Tremendous volume can be handled without showing any signs of distress, due to the provision of an exceptionally powerful speaker. Pick-ut terminals are also incorporated, and 2 change-over from radio to gramophone is accomplished by turning the dial to phono position. The Colonial Compact is a smalles set, 16 inches high, employing twe stages of screen-grid radio frequency, anc screen grid detector. All the vital parts

are made 50 per cent. over size, to ensure long life with trouble-free operation. The set also employs a four position tone control. The new models arriving shortly will include a radio gramophone combination which, though equal in all respects to the present model, will be not nearly so large as the standard combinations. Clarion Radio OR many years, the Transformer Corporation, of America, supplied manufactured materials for many of

America’s leading firms, and when last year they de-' cided to enter the receiver field they carried forward the good name they had earned in compotent manufacture. Their huge plant and experience enabled them to produce

everything that goes to make up a radio receiver at.a very low cost. And it must not be imagined that by making a set for a low sum the product was a cheap one; essentially it is not,-for they have gained a position among the leaders of radio in the States. This season | will see many of the new innovations incorporated in Clarion sets, the product of the Transformer Corporation. They will be displayed at the Auckland exhibition. The Silver Ghost Speaker HE Silver Ghost is a new Farrand inductor dynamic speaker. This type of speaker, which became very popular last year, works upon a different principle from the ordinary type in that it requires no field current and has two magnets arranged somewhat similarly. to the ordinary cone instead of the pot of the dynamic speaker. The armature moves parallel tothe face of the magnets, not perpendicular to them, as in the case of _the cone speaker. The’ Silver Ghost is provided with a special terminal panel at the back, by which the impedances can be matched to any valve or valves in push-pull. If an anode current of more than 20 amps. flows, however, a special output transformer should be used. The -Silver Ghost is obtainable either as a unit to be placed behind the baffle or in one of several different styles of attractive cabinets. The New Zealand agents are Messrs. L. M. Silver and Co. Ferranti IN England, Ferranti products are recognised as standard by all constructors, and this reputation is gradually extending to world-wide dimensions. One notices that’ even American experimenters are beginning to use Ferranti ’ components. This year new products will be sold in New Zealand, among these being two new transformers, a.f. 6 and a.f. 8. The a.f. 6 is very similar in appearance to the well known a.f. 5, but it has a core 50 ; per cent. larger and, notwithstanding the ratio is 7-1, the inductance is sufficiently hjgh to maintain the good quality " reproduction. The curve of this trans- . , former is similar to that of af. 3, but it gives double the amplification of that transformer. It has been designed for

use in receivers using grid leak detector, and only one audio frequency stage. The preceding: valve should have an impedancé not greater than 10,000 ohms., and the’ anode current should not exceed 6 mamps. It is thus admirably suitable for Single"valye amplifiers. AF. 8 has been designed to meet the need of those who require good results at a very low price. It has a ratio of 34-1, and an amplification curve which goes below 50 cycles and above 8000. . The new choke, B5, will be sold this year. Designed for use in power packs passing heavy current, it will take 160 m/as, and with this current has an inductaric#. of six henries. At 40 m/as: the inductance rises to 9. The d.c. resistance is .orly.-40... ohms. ; Philips Radio

HE "star" receiver of the Philips = »,display at the Auckland Radio Show will be their new model 2601, recently landed in New Zealand. It possesses several unique features. The cabinet, which is built of ‘an attractive brown mottled bakelite, stands about 2 feet 6 inches high, and is of the Lowboy type. The controls, which are mounted on a sloping recessed panel, are four in number, and comprise a combination gramophone and on-off switch, volume control, tone control, and a. single tuning control. The circuit, in the main, is identical with that of the popular Radio-player, and uses two stages of screened-grid radio . frequency, linear power detector, with a pentode in’ the final stage. ‘ Incorporated in this receiver is a new type of dynamic speaker-a permanent magnet speaker-recently developed in #ngland. Though ‘no field coil is used, it is as’ sensitive. and will give as. great an output as the ordinary dynamic, with the advantage that no hum or’ power scratches are present. Provision is also made for the attachment of an extra speaker. . The two open-work metal doors at the rear of the cabinet are fitted with gate switches, which automatically cut off the power when the doors are opened, Thus all danger of shock is eliminated. Three aerial tappings are provided, two of them for use with a frame aerial. The primary of the power transformer is fitted with five tappings, ranging from

111 volts to 240 volts a.c., thus enabling the receiver to be operated on any power between these extremes. Pick-up terminals are also provided, ard the volume obtainable is more than adequate for the average room. , The tone of this receiver, both on radio and on record’ reproduction, is unusually crisp and natural. ‘ ‘Lissen Limited NGLISH radio parts are gaining Breat popularity on the New Zealand market, and constructors will be interested to note that Lissen Limited are bringing out a wide range of new and interesting parts. Airline A SET new to the New Zealand market, but one which is very well known -in America, is the Airline. A wide range of models, which will suit one’s own requirements and match the furnishings of the home, will be made a silable to the New Zealand public dur‘ing the coming season. A feature of the Airline service is that the New Zealand Express Co., who are the New Zealand dist-ibutors, have engaged a staff of servicing experts, who will always be at the call of Airline users. Not only do the New Zealand Express Co. market an excellent line, but they see that the. product ‘stays sold." Airline is manufactured by one of the largest radio organisations in America. Stewart Warner

PROMINENT among this season's Stewart Warner receivers is the "Avon" console, a seven-walve all-electric model of particularly pleasing design. The cabinet stands 3 feet 4 inches in height, ‘and is built of American walnut, tastefully carved. The set employs three stages of screened-grid radio frequency, power detector, and one stage of audio, feeding into an imprdved push-pull stage. For the purpose of local reception, an aerial has beeri built into the cabinet, while, for increased sensitivity on long-distance reception, an antenna compensator to adjust the tuned circuits to the aerial used, has been included. Another attractive feature of the "Avon" is the provision made for attaching either a dynamic or a magnetic type speaker, or both, without extra attachments of any kind. Thus extra speaker leads for magnetic speakers may be run into other rooms without the difficulty of incorporating a special transformer.

Pick-up terminals are provided, and in addition provision.has been made for using this receiver for the reception of television when it appears. Silver Marshall Radio

»ILVER MARSHALL have produced two compact super-heterodynes, and these will be on the New Zealand market during the 1931 season. The Cadet is a smaller set than the usual console, and is housed ‘in an attractive cabinet, while the Compact uses the same chassis but the cabinet is very: much redtced until 't has become a: large midget. Although small in size there is no skimping, for these sets are designed tomaintain the good name of Silver radio. Both employ a pre-selector circuit, followed by a 227 as first detector. There are three stages of screen-grid intermediate frequency with a 227 power detector feeding through a transformer into push-pull 245’s, A high degree of selectivity has been obtained, and the sets each give 10 kilocycle selectivity often against 50 kilowatt stations within a few miles of the receiver. The sets are provided with tonic control, volume control and local and distant switches. Provision is made for a magnetic speaker or telephones. . St ‘ Atwater-Kent

a= [NTERESTING new models to suit a variety of tastes will be featured by Atwater-Kent this season. There js a new heauty in the design, a richer finish. The speaker opening will be cur-

tained with a special, unobtrusive new tone fabric. New and advanced engineering has been applied; and new heights of performance have been obtained. ‘The new sets have greater range and even sharper selectivity. Due to a remarkable compensating mechanism, all stations are widely separated; there is no crowding or’ jamming. The wanted station can be picked out quickly and easily on the quick vision dial, which has been for twelve ° months a feature of Atwater-Kent radio. All station. markings are in full view ‘from: any angle, and ‘the figures in -kilocycles are larze and legible and are fully enumerated for instant reading. The speaker is new and enlarged, possessing a richer tone, while the tone control gives four definite shadings from bass to treble. . The gramophone commbination 75P incorporates the. lates valves ‘and affords remarkable fidelity on reproduction. In addition ‘to the a.c. sets, the Atwater-Kent Golden Voice models are available for districts. where direct current is used and also where current is not available at all. They are still making up-to-date batery models. : Columbia » OLUMBIA batteries have established a wide reputation with dependability the world over, and their new product, the Air Cell, should be well received this season. Last week. we:had a very complete article on the new battery, and, just in passing, we might add that already it is being widely used. The new Air Cell has a two-volt battery which works on an entirély new principle, being specially designed to work with the new American 231 type valve, although it can be used with the ordinary 2-volts valve. The outstanding feature of the Air Cell is that no control device is necessary to regulate the "A" battery voltage. It is absolutely constant over a long period. Osram American Type Valves HE British General Electric Co. are marketing this season a new series of American type a.c. valves. These are exact replicas of the familiar American types, and can replace them in any socket. The "Radio -Record" laboratory has had a set of these for test and has found them equal in all respects to the standard valve. We have used them in super-hetero-dyne, ordinary T.R.F. sets in all stages, in shortwave sets and in Loftin-White amplifiers. In every case their performance left nothing to be desired. A point in their favour is that the time required for the heating of the -cathode of the indirectly heated valves has been cut down to a minimum. These valves are faster than in any others we have tested, taking only 10 to 15 seconds to reach an operating state. The types that we have seen are 227, 224, 245, and 280. It is indeed gratifying to note that English firms are manufacturing valves that can be employed in receivers used in New Zealand. Arcturus RCTURUS valves are manufactured in all.the commonly used American types, and are conspicuous by the blue colouration of the glass. It is interesting to note that the Arcturus Radio Tube Company claim to be the trail blazers of the radio valve industry on account of their being the first to produce standard base a.c. valves, isolated (Continued on page 14.) .

cathode valves, a.c. ‘long ufc satres quick heating 277 (it takes only seven seconds for. them to come into operation) and the acl. screen-grid valve. The latest valves, variable mus and pentodes, are, too, now being manufactured by Arcturus. Arcturus valves can be seen in many of the sets in the exhibition, notably the Clarion, Atwater Kent, and the Philco, Philips EVERAL new type valves have been recently added to the Philips range lately. The first, E442S, is a screened grid valve, differing chiefly from the E442 in that it has an appreciably lower impedance. It is excellent for use in radio-frequency stages, and may also be used with advantage as a detector or first audio vat.

The next, the E406, has been on the New Zealand market for some months, but is Vvorthy of mention because of its phenomenal characteristics. It has a slope, and an amplification factor, of 6, and at a bias of only 24 volts will deliver 2 watts undistorted output. It is an ideal low impedance valve for a single stage. The F443 is a new. 500-volt pentode, which with a negative bias of 30 volts draws 45 in A. Its undistorted

output 1s 10 watts. A new power valve, the C606, is the equivalent of the Osram P625. Among an up-to-date range of Philips transmitting valves recently landed are two, a 5 and a 10-watt type, which have already proved very popular among amateur transmitters. Mullareé WIDE range of Mullard valves is produced by the Mullard factories in England. The range now available

includes not only the improved version of the familiar Mullard types, but complete ranges of American replacement series and 4-volt a.c. valves. Some of these latter valves incorporate the newest ideas developed in British laboratories on valve manufacture. There is a wide range of rectifying valves for high voltage rectification and several . pentodes available in 2, 4 and 6 volts. New power pentodes will be available this season. Radiotron Valves PROMINENT among the latest Radiotron receiving valves recently landed in New Zealand by Amalgamated Wireless, A’sia, Ltd., is a new series of 2-volt valves-the 230, 231 and 232. These are very economical on both "A" and "B" battery current, give long service, and are altogether a new development. o% The 230 is a general-purpose valve suitable for use as detector, intermediate audio frequency amplifier, or radio-fre-quency amplifier, :

The 231 is an output valve designed for use as a last stage audio amplifier. It draws 13 amp. filament current and, with a negative grid bias of 22.5 volts, 8 m.amps. plate current. It has an amplification factor of 3.5, and delivers 170 milliwatts undistorted power output. The 232 is a screen-grid valve suitable for use as a radio frequency amplifier, detector, or intermediate audio-frequency amplifier, though it is recommended par-

ticularly tor use ds an r.f, stage valve. Its filament current is rated as .06 amp. and total "B" current is approximately 2 m.amps. It possesses an amplification factor of 440. Though designed primarily for operation in conjunction with the new Air Cell "A" battery, all these valves may be operated from dry cells, but a filament voltmeter should be constantly used, for if the voltage rating is exceeded the lives of the valves will be shortened.

.. Radiotron valve which has become very popular with constructors during the short period it has been on the market is the 221, a six-volt valve which, like the new series mentioned above, is exceedingly light on both plate and filament current. It is thus quite suitable for operation from dry cells as well as from storage batteries. It functions equally well as a detector and_an om-plifier-both radio and audio. Constructors will be pleased to learn that the price of this valve has been reduced from 20/- to 13/6. Kolster Brandes Speeaker We have received from Internationa! Radio a Kolster Brandes Speaker, and have just completed a test when used with a Loftin-White Amplifier. The speaker is of the permanent magnetic type, using a matching transformer, the inductance of which can be varied to suit the amplifier employed. In our amplifier we found the best results were obtained when the ratio was 23-1. As far as sensitivity was concerned, it was equal to the average cone speaker. It would just respond when coupled with a good crystal set, connected up with a big aerial. It would handle sufficient volume for the average home without any trace of distortion. We would estimate that the undistorted output would be approximately two watts. Upon testing it with the recording of yarious instruments we found that the speaking and singing voices left little to be desired. The orchestra came through well, whilst instruments in the extremes, such as the trombone and the piccolo,

could be picked out. The range which gave best results was that extending from about 200 up to 4000 cycles. There was a marked falling off after 100.