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saba: RE: PAPERS article - Funkschau 15 Jan 1939, page 4

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Forum » Radios and other type of sets (Physics) etc. » MODELS DISPLAYED » saba: RE: PAPERS article - Funkschau 15 Jan 1939, page 4
           
Robert Sarbell
Robert Sarbell
 
USA  Articles: 363
Schem.: 44
Pict.: 162
15.Nov.04 17:17

Count of Thanks: 9
Reply  |  You aren't logged in. (Guest)   1 All members interested in Saba early Superhets (and especially members who have a model 455WK OR a model S 455WK), I have manually typed in (using the German character keyboard) and translated the article described above.

The translated output (using the Babelfish software translator) is as follows:


WE LEADING FORWARD: SABA 455WK

Superhet - 8 circuits - 5 Tubes

Wave bands: 13.5 - 34, 30,-91, 200 - 600, 750 - 2000 m

IF - 485 kHz

As alternating current equipment available

Tube assembly: ECH11, EBF11, EFM11, EL11, AZ11

Power absorption: 55 Watts Connection for 2 loudspeakers: Impedance about 7000 ohms

Special characteristics: Two-stage entrance band filter; even a three-stage and two-stage IF band filter; Three-gang variable tuning capacitor

Range automatic controller (change of coupling with the 1st IF bandfilter), with tone quality automatic controller combined: Language - music switch: Volume control before the 1st NF stage

Three-fold decrease reconciliation, on mixer-, IF- and NF stage working co-ordination
Tuning indicator in form of a magic eye

Wood housing: Electro-dynamic loudspeaker


The use of steel tubes became as well known first only for alternating current receivers and for such over Rm. 285,00 and/or RM. 280.00 retail price approved, because it was not possible to produce from these new tubes in the first year so much that an indiscriminate assembly of the receivers would have been feasible. It would be however nothing wronger than that to want to conclude from the restriction of the steel tube price groups higher on the devices that this kind of tube would be applicable evenly only for the expensive receivers! In the opposite, straight for the receivers of low and middle price classes, will steel tubes the great importance attain, are nevertheless possible it with their assistance not to increase the achievement of these devices inconsiderably without for this higher expenditures would have to be made. An interesting example for this is the steel tubed Superhet Saba 455 WK, which niedrigst to permissible steel-tubed receiver price on the market was brought - the costs RM. 280,00, and which is anxious in addition to use the progressive technology steel-tubes fully. In the progression this receiver the standard super of the German market enspricht, i.e. it consists of the mixer, an intermediate frequency stage, the receipt electric rectifier, a NF preliminary stage and the output stage. At the entrance of the equipment zweikreisig it is band filters intended, in order to suppress disturbances by image frequencies. The selection means of the intermediate frequency amplifier are formed for band filters by dreikreiseg it and zweikreisig it, about which the first earns completely special attention: The second -- thus the middle -- circuit is used here for the bandwidth control, such that the position of its is changed at the same time to the coil first and that of the third circle. Beside its ground connection this adjustable circuit does not possess any connections outward; it can be trained consequently not only extraordinarily absorption-poor, but also all difficulties always resulting in from the inlets come themselves into abolishment. Band filter curves and bandwidth control are therefore from ideal form. Under supports becomes the bandwidth control by a bass/treble compensation, thus by a low-frequency working tone quality automatic controller, which represents circuit-moderately nothing different one, as a variable inverse feedback, which pre-amp tube between the anode of the output tube is arranged. With the help of this automatic controller one can raise the high or the bass tones after choice; the arrangement is thus superior to the usual bass/treble screen, with which the high tones are only cut off. To these means of the effect on the frequency band shown by the loudspeaker finally still another language music switch comes, by which a condenser switched into the inverse feedback way can be short circuit. The progressive characteristics of the steel tubes come primarily in the excellent short wave part of the equipment to the expression, considerably above all also by the fact that the KW range was partitioned considering the good efficiency of the receiver on short waves. In order to guarantee a very good synchronisation of the vorkreis and oszillatorkreis it also with the KW receipt -- a characteristic by the way, which is often neglected enough, received each short wave coil in entrance and in the oszillatorkreis their own trimmer.

It is not amazing therefore that the receiver on the short waves offers an extremely large selection of transmitters and in its sensitivity appears practically unrestricted, particularly since those does own liberty of frequenzverwerfungen the ihrige to the steel mixer tube, in order to maintain the optimal tuning of the equipment also when strong fluctuations the field strength. Also another important characteristic of the steel tubes, namlich the possibility of the automatic low-frequency regulation, is here used; the decrease reconciliation of the equipment affects on three stages, except on the mixing and the IF- stage also the low frequency - preliminary stage, in which the amplifier system of the magic eye EFM11 is used. Dadutch becomes the range of the automatic volume regulation in relation to the landlaeufigen design standard - Supers inconsiderably does not extend, a characteristic, which likewise primarily KW - receipt benefits. The advantages of the new Saba - equipment lie however not only in tubes and circuit, but also in the mechanical structure. In the equipment new spulensaetze are used, with which the Amenit - cam-operated switches directly at the lower end of the coils - is arranged carrying construction, so that the switches with the spulensaetzen form a unit; this mechanically and electrically equal high-quality design brings a substantial reducing in price in relation to the earlier arrangement also -- in the rest of perfectly totally enclosed -- the variable capacitor was again designed; consequently the stators were stored with the help of ceramic spacer distance pieces in the pulling tub, the dielectric losses remain very small. The current supply at the rotors takes place -- at each rotor for itself -- via strong leaf springs with precious metal contacts, in order to secure small transition resistance and avoid interruptions. A finely ueberestzter flywheel drive makes a sensitive and exact tuning possible. To these receivers -- which applies likewise to the other Saba receivers of this year -- in addition, the radio practical man in the workshop to apply, thought large interest one into to him and its desires nevertheless more, than it is customary. The receiver rack is particularly easy with this equipment to develop; one does not need to unsolder the loudspeaker cord, but one has to pull only a vierpoligen plug, in order to separate with grasps all loudspeaker connections. The scale is down developed on the rack, and also the magic eye is down inserted, so that these two parts can to be comfortably pulled out with the chassis and no separate treatment require. A removable base plate makes it possible to approach to the most important measuring points and parts at all without development of the equipment. Also all abgleichschrausind easily accessible; as far as the alignment elements lie in the pots, are screw after acceptance of a cap attainable, by which alignment openings can be locked later again; thus that is protected surely inside of the coil pots against making dust.
Erich Schwant


Please note that I have intentionally NOT CORRECTED all of the text above in order to help stimulate the interest within the English-speaking members, and to encourage all members to add possible items of interest to the models with non-typical circuits, and receivers introducing exceptional merit.

Respectfully,
Robert
PS: I have received much technical assistance from several members thus far, and offer special thanks to Herren Hauf and Menke.

This article was edited 21.Jan.06 15:52 by Robert Sarbell .

Thomas Günzel
Thomas Günzel
Editor
D  Articles: 212
Schem.: 1124
Pict.: 555
01.Oct.06 16:28

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Reply  |  You aren't logged in. (Guest)   2 Liebe Saba Freunde,

Anbei noch der Originalbericht aus der Funkschau 03/1939











 Gerätebericht

Viel Spaß beim Lesen

Thomas
Omer Suleimanagich
Omer Suleimanagich
 
USA  Articles: 427
Schem.: 3
Pict.: 56
02.Oct.06 03:21

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What an advanced radio for 1939!

Thanks Robert for presenting this information.

Recently, I found this radio, Siemens 13W,  on EBay(see attachment), and I am fascinated at the build quality of a radio and the technology used for its time.  Especially considering that this radio was manufactured in the middle of WW II.

If the radio is working per EBay ad, I might consider just running it on its original caps(please let me know if there are other suggestions to retain the value of this radio)

Attachments:

This article was edited 02.Oct.06 03:27 by Omer Suleimanagich .

  
rmXorg