REX (ZANUSSI) SR23 YEAR 1964.

The REX  (ZANUSSI)   SR23   is a 23 inches B/W television with tubes technology from ZANUSSI.

It has VHF and UHF channels selectors and is one first model series having both channel tuning type from ZANUSSI Industry.
The channel selectors are located on the right side of the wooden cabinet.

Tuning is obtained with rotatable drum selectors for VHF and variable rotatable capacitor for UHF.
A rotatable drum containing twelve pre-defined channel-specific filters determines the received channel, where the inductors of the input matching, the channel filter and the LO tank circuit are changed. The tuner is divided into two chambers for maximum isolation between the sensitive RF input and the mixer-oscillator-IF section with its much larger signals. Also on the drum there are eventually two separate sub-modules.
It's completely based on tubes technology.
With this concept, which essentially turned the tuner module into a kind of Lego building block construction, many different tuners became possible. Depending upon the country of destination and its associated standard and IF settings, the required filter modules would be selected. Service workshops and tv fabricants could later even add or exchange modules when new channels were introduced, since every inductor module had its individual factory code and could be ordered separately. As a consequence more versions of the tuner were produced, covering at least standards B, B-for-Italy, C. E, F and M.


The principle of the drum tuner. On an axis two times 12 regularly spaced channel-specific filter modules are mounted. In front are twelve channel filter modules for both the channel filter and LO tank circuit tuning. Seven contacts are available, and one module is shown removed. The second row contains 12 modules with five contacts for the input filter circuit. In the tuner module the front section (for mixer-ocillator and channel filter) is separated by a metal shield from the rear RF input and pre-amp section. [Philips Service "Documentatie voor de kanalenkiezers met spoelenwals", 1954]

Examples of the filter modules as used in the drum tuner. Left the 5-contact input filter, right the 7-contact BPF and LO tank filters. In both modules the coils are co-axial for (maximum) mutual coupling.





The second new valve introduced in the tuners family was the PCF80, a triode-pentode combo valve specifically designed for the VHF mixer-oscillator role. First order the circuit principles didn't change too much from the previous ECC81 based generation, with the triode acting as a Colpitts oscillator with a tuned feedback from anode to grid. The oscillator voltage was minimally 5V at the grid, and would be inductively coupled to the input of the mixer pentode. This inductive coupling was achieved by putting the oscillator coil S7 and the BPF coils S5 and S6 on the same rod inside the drum tuner filter modules, see Fig.5 above. By adjusting the distance between these coils for each channel filter module, the coupling constant could be kept more or less constant across all channels, providing as much as possible a frequency-independent mixer performance. For the mixer the pentode replaced the previous triode, providing more feedback isolation between anode and grid. All in all the new tuner must have given a considerable performance improvement compared to the previous generation.

The B/W Tubes Television set was powered with a External Voltage stabiliser unit for Television (portable metal box) which relates to voltage regulators of the type employed to supply alternating current and a constant voltage to a load circuit from a source in which the line voltage varies.Conventional AC-operated television receivers exhibit several undesirable performance attributes. For example, under low-line voltage conditions such as those encountered during peak load periods or temporary power brown-outs imposed during times of power shortage, picture shrinkage and defocusing are encountered and under extreme brown-out conditions the receiver loses synchronization with a resultant total loss of picture intelligibility.

On the other hand, abnormally high-line voltage conditions are sometimes encountered, and this can lead to excessive high voltage and X-ray generation. In addition, either abnormally high steady state line voltage conditions or high voltage transients such as those encountered during electrical storms or during power line switching operations may subject the active devices and other components of the receiver to over-voltage stresses which can lead to excessive component failure.

It is a principal object of the present invention to provide a new and improved AC-operated television receiver having greatly improved performance characteristics in the presence of fluctuating power supply voltages.

A more specific object of the invention is to provide an AC-operated television receiver affording substantially undegraded performance under even extremely low-line voltage conditions without excessive high voltage and X-ray generation under even extremely high-line voltage conditions.

Still another and extremely important object of the invention is to provide a new and improved AC-operated television receiver having greatly improved reliability against component failure. Such regulators are frequently provided employing saturable core reactors and condensers connected in circuit...  in such manner as to provide a plurality of variable voltage vectors which vary in different senses, as the line voltage varies, but which add vectorially in such manner that t
voltage stabilization
is automatically effected by the provision of an inductive pilot control device which is adapted to provide two excitation supply voltages for producing excitation or satuation of two magnetic circuits of a reversible booster transformer unit or units and diversion of flux from one magnetic circuit to the other, the booster unit being energized by primary windings from the A. C. supplysystem and being provided with a secondary winding or windings connected between the supply system and the corresponding inain or distribution circuit and in series therewith, through which a corrective boost voltage is
introduced into the circuit under the influence of the pilot control device, of an amount equal to that of the supply voltage fluctuation which initiated it and appropriate in polarity and direction for restoring the voltage to normal value and providing automatic stabilization of the circuit voltage against supply voltages which fluctuate above and below normal value.

Their vector sum remains substantially constant upon variations in line voltage, for providing automatic voltage stabilization of single or multiphase A. C. circuits where the supply voltage and frequency are subject to variation above and below normal value and where the load is subject to variation between normal limits.
The pilot control device which may be employed singly or may comprise three units or their equivalent when applied to multiphase supply systems comprises a pair of closed magnetic circuits or cores constructed of strip wound magnetic material or stacked laminations, the two
circuits forming a pair being constructed of materials possessing dis~similar magnetic characteristics when jointly energized by identical windings in series or by a collective primary winding, the said magnetic circuits being suitably proportioned to provide equal fluxes when energized at normal voltage.

The pilot control device is provided with a main and an auxiliary secondary winding or group of windings, the main secondary winding or windings being adapted to provide a voltage representing the difference in the fluxes of the two circuits to which it is jointly associated, while
the auxiliary secondary winding embraces only one circuit, preferably that subject to the least amount of flux variation. Either of the windings consists of two equal sections or in effect a double winding with a center tapping to which one end of the single winding is connected.

The voltage in the single secondary winding of the pilot device becomes directionally additive to that in one half of the tapped secondary winding a nd substractive in respect to that in the other half. When the supply voltage is normal the voltage provided by the single secondary winding is zero, since there is no difference of flux in the two magnetic circuits, and the two excitation voltages
produced in the halves of the other secondary winding are equal and when connected to the two excitation windings of the booster units, do not produce any diversion of flux between the two circuits or sets of circuits in the magnetic system of the booster transformer unit become equal, and since the series winding on the booster unit is arranged to provide a voltage due to the difference of
the fluxes in its two magnetic circuits or sets of magnetic circuits, no corrective voltage is introduced into the main circuit by the booster. If, however, the supply voltage varies from normal the pilot control device provides a voltage across the one secondary winding due to the difference in the fluxes of the two dis-similar magnetic circuits of which it is comprised, which voltage is combined with thosc in the halves of the other secondary winding to provide two excitation voltages which vary complementarily to each other as the supply voltage fluotuates, and cause a transference of flux between the two
circuits or groups of circuits in the booster unit and automatically provide a corrective boost voltage in the main circuit in which the series winding of the booster transformer is included of a value equal to that of the variation in supply voltage which initiated it.
The pilot device may be arranged in various ways, forboth single phase and multiphase operation, as exemplified by the constructions hereinafter more fully described.Similarly, numerous arrangements of the booster transformer unit are possible, some of which are hereinafter described in detail. The booster transformer unit embodies thc principles of the inductive devices described in my co-pending Application No. 411,189, filed February 18, 1954.

As an alternative to the provision of an auxiliary secondary winding on the pilot control device this may be
replaced by an independent or external source of supply,which may be either subject to or independent of supply voltage variation, provided such supply may be arranged with a center tapping if required.

Feed-back arrangements may be employed for providing compensation against voltage drop due to the effects of load in various ways. These are preferably providedon the booster transformer unit and may comprise a current transformer in one or more lines of the main circuit,
the secondary output of the transformer being rectified and arranged to energize an additional excitation winding on the booster transformer unit which in clfect increases the amount of the corrective boost voltage as the load increases.

Zanussi was an Italian producer of home appliances that in 1984 was bought by Electrolux . Zanussi is a leading brand for domestic kitchen appliances in Europe. Products have been exported from Italy since 1946.

The Zanussi Company began as the small workshop of Antonio Zanussi in 1916. The enterprising 26-year-old son of a blacksmith in Pordenone in Northeastern Italy began the business by making home stoves and wood-burning ovens.
After his father death in 1946 “Lino Zanussi” became the President of the company.
In the early 1970s Zanussi sold a lot in the UK and for some time after under the “Zoppas” brand, name which had been acquired, making Zanussi the first largest Italian appliance maker. They also produced washing machines Hotpoint for Hotpoint at this time which were very reliable and highly rated by users and engineers.
In the late 1970s and into the early 1980s the company had a range of washing machines which used an induction motor with a clutch pulley system. Again this range proved extremely popular and very reliable.
During this period Zanussi Professional, the catering range of appliances for commercial use, became a separate division in its own right.
In the early 1980s Zanussi launched the Jetsystem washing machine range to great acclaim whilst at the same time running the “Appliance Of Science” advertising campaign which is acknowledged as one of the most successful marketing campaigns of all time, in fact still remembered by many today. This gave the brand the impression of being forward thinking and innovative.
Zanussi has recently been rebranded as Zanussi-Electrolux in line with many other Electrolux brand names. Since that time many Zanussi appliances share common components and parts with the rest of the Electrolux range, primarily Electrolux, Tricity Bendix and AEG although it is worth noting that the “John Lewis” branded machines sold by the John Lewis Partnership in the UK are effectively rebranded Zanussi appliances.
In the late 1980s Zanussi launched the split tank design known as the “Nexus Tub” design which endures to this day with little change. The tub, base and certain other parts are made from a plastic material known as “Carboran” which can be re-used several times if recycled. To this day neither Zanussi or Electrolux has provided any way to return this material for recycling purposes.

Up until the end of the 1980s Zanussi service was run from Slough and was a network of independent repairers who gave an unparalleled service level. It is generally acknowledged within the industry that this service network was the best that there has ever been in the UK.
In the early 1990s Electrolux instigated amalgamating all its UK brands under one service entity. This entity was split, dependent on region, between the Zanussi service agents and the local Electrolux Service Centre. In general those in a high population density area where given to the Electrolux employed centres. Tricity Bendix, Electrolux and AEG as well as Zanussi were all to be serviced by the one network.
This was changed in the late 1990s and early 2000s as Electrolux sold or gave away the regional service centres, generally to the existing management or to area managers to run as independent businesses.
This service network was rebranded and became Service Force which still exists today but is, once again, all operated by independent service companies who repair and supply spare parts for all of the brands.................

 ..........................when the president Lino Zanussi died in a plane crash in June 1968 - Zanussi
Industries was the first Italian manufacturer of white goods and employs approximately 13000 employees.

When the Zanussi group of Pordenone lives a first phase of  financial stress then Lamberto Mazza, who succeeded Lino Zanussi, decides to liquidate some social funds with share capital held by Guido Zanussi  causing an outlay of 16 billion lire of that era.

Despite the Huge outlay to cope with such a withdrawal, the group aquired, in the course of 1970, competitor like Zoppas the other big Italian manufacturer of household appliances, which was,
significantly in debt due of an acquisition of Triplex in Solarolo and a construction of the new plant in Susegana.

The Zoppas, whose factories were located in Conegliano Veneto (TV), has a history quite similar to Zanussi: it is in fact founded by Ferdinand Zoppas in 1926 as an artisan company repair of wood-burning stoves and then spread widely and rapidly under the leadership of his sons Augusto and Gino.

Zanussi president, Lamberto Mazza, alleged a plan to achieve an optimal size to compete at the European level if not the world, strengthening the shares held by Zanussi on the Italian market to avoid  the entry of foreign competitors (in particular the U.S. Westinghouse).

The Financial stress imposed on Zanussi by acquisition of Zoppas and, simultaneously, the increase in the incidence both of labor costs and reasons of rise up of activity intensity (In the space of a short pass from 13,000 employees to 24,000 units?)  is faced with:

a. the sale to the German AEG-Telefunken
an amount equal to 25.01% of the Zanussi S.p.A.
(The operational holding company of the group)

(The share of ownership AEG-Telefunken is subsequently recognized in 1978 by Voet-Alpine.)


b. to loans from Italian Istituto Mobiliare
(IMI);

c.
about a loan of about two hundred million marks
disbursed in 1974 from Dresden Bank.

The union conflicts, the impact of labor costs (in 1974 Zanussi occupies nearly 31,000 employees), the Debt contract with institutions credit and the first oil shock induce Lamberto Mazza to start a rapid process of diversification The core of this strategy is, however, the belief that the market of appliance White has come to its stage of maturity, with a saturation level  and the consequent reduction of typical viability.

Therefore, in this back of years Zanussi invests substantial financial resources to acquiring control of businesses;

(The process of growth of Zanussi,  nevertheless sees the creation of new realities companys as a result of corporate spin-offs.

Considering, for example,

Zanussi Grandi Cucine SpA, Zanussi Grandi Impianti
SpA, Air Zanussi SpA, Zanussi Components for Construction SpA, the Industrialised Building ZanussiFarsura SpA to subsidiaries Iberian Zinsa-Zanussi Industrial SA Compania SA and Industrias Electrodomesticas,
and Lastly Anglo-Saxon Iaz International Ltd., was established in 1979
well as the company insurance and financial intermediation
group, called Infinas S.p.A.) with few exceptions   activities not related with the core business.

In particular, remembering the concentrations of corporate sectors relating to paper (Paper Mill Galvani SpA, Cartopiave SpA and subsidiaries Cartosud and Silica), electronic (Ducati Electrical, Electronics-Inelco), construction (Seicom-Building for Integrated Components SpA), metallurgical (Smalteria and Metallurgical Veneta SpA), hotel (Borsa SpA) of furniture (Galvani Porcelain SpA, Sambuceto SA, Meson's Spring SpA SpA and its subsidiaries and Pagnucco SpA), components (Ilpea Gomma SpA), photographic equipment ( Fotomec San Marco SpA) of entertainment
(Udinese Calcio SpA) and solar photovoltaics.

(The investments of Zanussi happenned sometimes even in the indirect form
 which is made through the CISVE (Industrial Consortium
Economic Development), founded by Lamberto Mazza in quality of
President of the association of Industrialists of Pordenone, as well, since 1978, through the Industrial Finance SpA, a company financial system constituted specifically for that.)

the Organization Company is  formed in a matrix in which the divisional activities and  are then grouped into the following sections:

1.apparatus for heating;
2.components for Building;
3.solar panels;
4.apparatus Idronet (for potability of the water);
5.components;
6.apparatus different from electronic television sets.

But when the financial situation Worsened in 1983,
Zanussi family the shareholder majority, distrusted Lamberto Mazza replacing him
initially with Umberto Cuttica, former manager of FIAT,
then later with Gianfranco Zoppas, husband of Antonia Zanussi and son Lino.

The corporate reorganization plan was then prepared by the new management and was designed to focus the now scarce financial resources in the core business of group, to continue or to divest a number of activities not closely related ( Air Zanussi, Zanussi Construction Industrialized, Zanussi Electronics, Paper Mill Galvani,Pagnucco, Fotomec, New Cartopiave) , thus preparing the field for the sale of the Entire group to Electrolux, the Swedish multinational leader in field of white goods.



Stern / REX / Zanussi / Seleco (WAS) is an electronics company based in Pordenone, Friuli Venezia Giulia, Italy. It is part of Super//Fluo, who bought the rights in August, 2006, along with Brionvega and Imperial.


Sèleco was born as in 1965 as a spin-off from the home appliances maker Zanussi. In the first years of his life, Seleco produced almost black and white televisions with the Zanussi or Rex brand. The company was being sold in 1984, and was first acquired by Gian Mario Rossignolo. He first became president and then main stockholder.
During the 1980s, the company launched worldwide marketing campaigns and began sponsoring some of the most famous Italian soccer team, such as Lazio A.S..
During the '90s, the company was mainly concentrated on the production of pay-tv decoders, but in 1993 suffered from a loss of competitivity. With the intent to reshape its position and to get gave new life to the company, Gian Mario Rossignolo bought Brionvega from the Brion family, the founder. This attempt get to nowhere, so the company was forced to declare failure in 1997. During the years, Sèleco has passed through ups and downs, at the end being overcome by the continuous changes in the electronics world.
After the crack-down, the company and all its interests were bought by the Formenti family. That gave life to the Seleco-Formenti Group, owner of the rights for the brands Sèleco, Rex, Phonola, Imperial, Stern, Phoenix, Televideon, Kerion and Webrik.
The Formenti family re-launched the company with the production of CRT-TVs. In 2000, the company suffered of a strong crisis, following the price dumping made by Turkish manufacturers. That seems to led to end of the Sèleco and Brionvega story, as the Sèleco-Formenti Group was forced to liquidation.
In 2004, the rights for the radio branch were bought by Sim2 Multimedia, and all the television interests (for the brands Sèleco, Brionvega and Imperial) were acquired by Super//Fluo in August 2006.

THIS INDUSTRY IS TODAY DEAD !!!!

A good point  on good  old  B/W Televisions.....................

The Sixties was a time of great change for TV. At the start of the decade there were just monochrome sets with valves, designed for 405 -line transmissions at VHF. By the end there was 625 -line colour at UHF, with transistorised chassis that used the odd IC.

The following decade was one of growth. The "space race" had begun in 1957, when the USSR launched Sputnik 1 and terrified the Americans. Thereafter the USA began to spend countless billions of dollars on space missions. This got underway in earnest in the Sixties, with the announcement that America would be going all out to get a man on the moon by the end of the decade. There followed the Mercury series of earth - orbit missions, then the Apollo launches. Success was achieved in 1969. Most of these missions were televised, and in those days anything to do with space was hot stuff. It was inevitable that everyone wanted to have a television set. At the time an average receiver would be a monochrome one with a 14in. tube - there was no colour until 1967. It would cost about 75 guineas. 
TV sets were often priced in guineas (21 shillings) as it made the price look a bit easier on the pocket. Anyway 75 guineas, equivalent to about £78.75 in 2000's currency, was a lot of money then.  For those who couldn't, rental was a good option. The Sixties was a period of tremendous growth for rental TV. 
Much else was rented at that time, even radios, also washing machines, spin driers, refrigerators and, later on, audio tape recorders (no VCRs then). 
For most people these things were too expensive for cash purchase. 
There were no credit cards then. And when it came to a TV set, the question of reli- ability had to be taken into account: renting took care of repair costs. 

TV reliability.........The TV sets of the period were notoriously unreliable. They still used valves, which meant that a large amount of heat was generated. The dropper resistor contributed to this: it was used mainly as a series device to reduce the mains voltage to the level required to power the valve heaters. These were generally connected in series, so the heater volt- ages of all the valves were added together and the total was subtracted from the mains voltage. The difference was the voltage across the heater section of the dropper resistor, whose value was determined by simple application of Ohm's Law. 
As valves are voltage -operated devices, there was no need to stabilise the current. So the power supply circuits in TV sets were very simple. They often consisted of nothing more than a dropper resistor, a half or biphase rectifier and a couple of smoothing capacitors. If a TV set had a transformer and a full wave rectifier in addition to the other components, it was sophisticated!
 As the valve heaters were connected in series they were like Christmas -tree lights: should one fail they all went out and the TV set ceased to function. Another common problem with valves is the cathode -to -heater short. When this fault occurs in a valve, some of the heaters in the chain would go out and some would stay on. Those that stayed on would glow like search- lights, often becoming damaged as a result. Dropper failure could cause loss of HT (dead set with the heaters glowing), or no heater supply with HT present. When the HT rectifier valve went low emission, there was low EHT, a small picture and poor performance all round. CRTs would go soft or low emission, the result being a faint picture, or cathode -to -heater short-circuit, the result this time being uncontrollable brightness. On average a TV set would have twelve to fourteen valves, any one of which could go low -emission or fail in some other way. All valves have a finite life, so each one would probably have to be replaced at one time or another. The amount of heat generated in an average TV set would dry out the capacitors, which then failed. So you can see why people rented! 

The CRT could cause various problems. Because of its cost, it was the gen- eral practice to place its heater at the earthy end of the chain. In this position it was less likely to be overloaded by a heater chain fault. But during the winter months, when the mains voltage dropped a bit, it would be starved of power. This would eventually lead to 'cathode poi- soning' with loss of emission. The 'cure' for this was to fit a booster transformer designed to overrun the heater by 10, 20 or 30 per cent. It would work fine for a while, until the CRT completely expired. At about this time CRT reactivators came into being - and a weird and wonderful collection of devices they turned out to be. Regunned tubes also started to appear. You couldn't do this with the `hard -glass' triode tubes made by Emitron. These were fitted in a number of older sets. Yes, they were still around, at least during the early Sixties.



Developments................... A great deal of development occurred during the Sixties. Many TV sets and radios made in the early Sixties were still hard -wired: the introduction of the printed circuit board changed the construction of electronic equipment forever. The first one was in a Pam transistor radio. PCBs were ideal for use in transistor radios, because of the small size of the components used and the fact that such radios ran almost cold. 
They were not so good for use with valve circuitry, as the heat from the valves caused all sorts of problems. Print cracks could develop if a board became warped. If it became carbonised there could be serious leakage and tracking problems. In addition it was more difficult to remove components from a PCB. Many technicians at that time didn't like PCBs. As the Sixties progressed, transistors took over more and more in TV sets. They first appeared in a rather random fashion, for example in the sync separator stages in some Pye models. Then the IF strip became transistorised. Early transistors were based on the use of germanium, which was far from ideal. 

The change to silicon produced devices that were more robust and had a better signal-to-noise ratio. 
Car radios became fully transistorised, and 'solid-state' circuitry ceased to be based on earlier valve arrangements. Many hi-fi amplifiers had been transistorised from the late Fifties, and all tape recorders were now solid-state. 
Both reel-to-reel and compact -cassette recorders were available at this time. Initially, audio cassette recorders had a maximum upper frequency response of only about 9kHz. 
To increase it meant either a smaller head gap or a faster speed. Philips, which developed the compact audio cassette and holds the patents for the design (which we still use in 2000!) wouldn't allow an increase in speed. Good reel-to-reel recorders had a fre- quency response that extended to 20kHz when the tape speed was 15in./sec. 
This is true hi-fi. In time the frequency response of compact -cassette recorders did improve, because of the use of better head materials with a smaller gap. 
This led to the demise of the reel-to-reel audio recorder as a domestic product We began to benefit from spin-offs of the space race between the USA and the USSR. 
The need to squeeze as much technology as possible into the early computers in the Mercury space capsules used by the USA lead to the first inte- grated circuits. 
This technology soon found its way into consumer equipment. Often these devices were hybrid encap- sulations rather than true chips, but they did improve reliability and saved space. The few chips around in those days were analogue devices.  To start with most UHF tuners used valves such as the PC86 and PC88. They were all manually tuned. Some had slow-motion drives and others had push -buttons. They didn't have a lot of gain, so it was important to have an adequate aerial and use low -loss cable..............................