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Thursday, July 18, 2013

WEST (SEIMART) TV12P YEAR 1978.







The  WEST (SEIMART)  TV12P is a 12 inches (31cm) B/W portable television with 8 programs keyboard push button and potentiometric tuning search system. The set allows mains 220volt supply and 12volt supply DC type.
Recently, it has become more popular than ever to watch TV in a car as the number of cars increases. In general, a storage battery of 12 volts is used in small cars while one of 24 volts is used in large cars so that there is a disadvantage that a separate power supply device is required for driving a TV set in compliance with the respective battery used in the car. The present invention relates to a power supply circuit of a television receiver used in an automobile, and in particular to a power supply circuit of a television receiver which enables two different voltages from two kinds of supply respectively mains at 220v and dc 12v.

The mechanical turret approach to television tuning has been used almost exclusively for the past 60 years. Even though replete with the inherent disadvantages of mechanical complexity, unreliability and cost, such apparatus has been technically capable of performing its intended function and as a result the consumer has had to bear the burdens associated with the device. However, with the " recent "  Broadcast demands for parity of tuning for UHF and VHF channels, the increasing number of UHF and cable TV stations have imposed new tuning performance requirements which severely tax the capability of the mechanical turret tuner. Consequently, attempts are now being made to provide all electronic tuning to meet the new requirements.
The use of voltage-variable diode-capacitors, such as varactor diodes, permits the electronic tuning of radio receivers and television receivers by the use of DC control voltages; so that the tuning elements no longer need to be intimately associated with the tuner. Thus, the tuned circuits of the tv receivers may be located remotely from the devices used to provide the necessary DC tuning voltages. In addition, the compact size of the voltage-variable diode-capacitor tuning circuits makes it desirable to use such tuning circuits in many tv applications which formerly used mechanically adjusted variable capacitors or the like as the tuning elements.

To employ voltage-variable diode capacitors in pushbutton tvs, however, especially in multiband pushbutton tv sets , a problem exists in providing a "memory," so that operation of a pushbutton will provide consistent tuning of the tv receiver to the station which is to be selected by that pushbutton. In addition it is necessary to provide some means for providing the initial tuning of the tv receiver for each pushbutton location in a manner which is reliable and inexpensive.
The invention relates to a tuning unit with bandswitch for high frequency receivers, especially radio and television receivers, having a potentiometer system for the control of capacity diodes, the said potentiometer system consisting of a plurality of parallel resistance paths along which wiper contacts can be driven by means of screw spindles disposed adjacent one another in a common insulating material housing in which a bandswitch formed of metal rods is associated with each tuning spindle.
In these tuning units, the working voltages of the capacity diodes in the tuning circuits are recorded once a precise tuning to the desired frequency has been performed. A potentiometer tuning system has great advantages over the formerly used channel selectors operating with mechanically adjustable capacitors (tuning condensers) or mechanically adjustable inductances (variometers), mainly because it is not required to have such great precision in its tuning mechanism.
Tuning units with bandswitches formed of variable resistances and combined with interlocking pushbuttons controlling the supply of recorded working voltages to capacity diodes are known. Channel selection is accomplished by depressing the knobs, and the tuning or fine tuning are performed by turning the knobs. The resistances serving as voltage dividers in these tuning units are combined into a component unit such that they are in the form of a ladderlike pattern on a common insulating plate forming the cover of the housing in which the tuning spindles and wiper contacts corresponding to the variable resistances are housed. The number of resistances corresponds to the number of channels or frequencies which are to be recorded. The wiper contact picks up a voltage which, when applied to the capacity diodes determines their capacitance and hence the frequency of the corresponding oscillating circuit. The adjustment of the wipers is performed by turning the tuning spindle coupled to the tuning knob. By the depression of a button the electrical connection between a contact rod and a tuning spindle is brought about and thus the selected voltage is applied to the capacity diodes. Since the push buttons release one another, it is possible simply by depressing another button to tune to a different receiving frequency or a different channel, as the case may be.
 Moreover, using this arrangement, the only indication--during adjustment--of which channel is selected is by station identification.

It has a Transistorized horizontal deflection circuits  made up of a horizontal switching or output transistor, a diode, one or more capacitors and a deflection winding. The output transistor, operating as a switch, is driven by a horizontal rate square wave signal and conducts during a portion of the horizontal trace interval. A diode, connected in parallel with the transistor, conducts during the remainder of the trace interval. A retrace capacitor and the deflection yoke winding are coupled in parallel across the transistor-diode combination. Energy is transferred into and out of the deflection winding via the diode and output transistor during the trace interval and via the retrace capacitor during the retrace interval.
In some television receivers, the collector of the horizontal output transistor is coupled to the B+ power supply through the primary windings of the high voltage transformer.

RADIOMARELLI (society of the group Magneti Marelli) has been
one of the most famous radio receivers industries: it was founded in 1891 as
Industria Elettromeccanica Italiana by ERCOLE MARELLI.
Radiomarelli was founded in 1929 from the Magneti Marelli company.

Between 1920 and 1930 there was a linkage from this Italian company and the American Bosch about the manufacturing of magnets and electrical parts for motor vehicles.

On 11.19.1930, the Magneti Marelli decided to start the radio production and the new company was named Radiomarelli.

The Radiomarelli project manager was Mr. B.A.Quintavalle and the first radio models, made in Italy, were inspired to the American Bosch models.

At that time, Radiomarelli and American Bosch were business partners.

The diagrams and the chassis of the first Radiomarelli models were similar to the ones of American Bosch models, the wood cabinets were a bit different.

The “Musagete” model has the same chassis of the A. Bosch mod. 48 and the wood cabinet was made in Italy but is very similar to the American model.

The “Coribante” model is the Italian version of the A. Bosch mod. 5.

The “Scrigno” model was the Italian version of the Bosch 200A & 200B models.

The chassis of the “Alauda” is very similar to the one of Bosch 402.
From 1935 onwards Radiomarelli decided to create a more independent production.
And obviously DIED like all Italian Industry..........

But before, it was aquired from the conglomerate of ELCIT AND SEIMART which was a joint developed by GEPI a government special system invented to "save" industry with "some" difficulties (!!!)


The tellye here in collection is a ELCIT branded RADIOMARELLI

SEIMART / ELCIT and its conglomerate was even proprietary of brands like:

ETERPHON KENNEDY RAYMOND VISIOLA and DAMAITER.

and

MAGNADYNE +

KENNEDY


Founded in 1922 in Torino ELCIT was a Radio fabrication industry which in the 1953 joined Visiola to produce television sets and other domestic appliances such washing machines and fridge.

ELCIT Was even proprietary of the MAGNADYNE brand which WAS a radio and Television well known brand.

In the 1960 the society was joined and aquired by SEIMART because of a market contraction which landed to GEPI a new society which re - founded ELCIT.

The conglomerate of ELCIT AND SEIMART which was a joint developed by GEPI a government special system invented to "save" industry with "some" difficulties (!!!) was unified.


NOTE:
SEIMART and its conglomerate was even proprietary of brands like:

ETERPHON KENNEDY RAYMOND VISIOLA and DAMAITER.

and

MAGNADYNE +

KENNEDY
and;

The following sub brands were even from the group but were specialized in other fields like
preparing materials, developing parts and other jobs like domestic appliances and even CRT TUBE manufacutring.

NEOHM was a resistor fabricant and was part of the group

Basically the industry group was completely autonomous exept for semiconductors which were coming from other well known brands and manufacturers.

RADSET
VISSET

NEOHM was a resistor fabricant and was part of the group


VITAUT
STAMPLAST
STAMFER

BOBSET
CIRSTA
FRIMAX
MOBFER P

TRAMAX
FINPLAST
VALVEX

ELCIT died in 1998 by typically Italian Industry Destroy culture (and , of course, chinese and turkish (super)CRAP basar !) and all workers and employee landed.......... on the street !!!!!!!!!!!!!

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