MAGNADYNE TV17P "ZEUSI" YEAR 1977.

The MAGNADYNE TV17P "ZEUSI" is a 17 inches B/W Portable television with a piramid design cabinet and 8 programs with potentiometric search tuning.
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 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.
For many years, mechanical turret tuners have been commonly employed in television receivers to select the VHF channels and a second rotary or continuous tuner has been used to select the UHF channels. For most television receivers, this requires two different channel selection knobs; and the tuners themselves are relatively bulky and require a relatively large amount of space within the television receiver cabinet. Because of the nature of these tuners, it also is necessary to locate them directly behind the front level panel of the receiver, which imposes significant restrictions on the cabinet design and the arrangement of parts within the cabinet, reducing the flexibility of design which would be possible if such tuners could be eliminated.

Some mechanical tuners are equipped with programmable switches to permit them to be used to select either a UHF or a VHF channel at a tuner position by programming the tuner for the local area where the television receiver is to be used. The disadvantages of the cumbersome mechanical tuners, however, are not overcome. Instead, the tuner is made even more complicated by such an arrangement.

It is desirable, and in the U.S./Europe it was  necessary, to effect selection of the UHF and VHF channels in a comparable manner. When such tuning compatibility is imposed, significant problems are encountered in providing a mechanical turret-type tuner having detented positions for all of the possible UHF channels which must be accommodated for television receivers capable of operating in any given locality in which the receiver is capable of receiving transmitted television signals. UHF turret tuners with detent tuning selection for each of the 70 possible UHF channels are difficult and expensive to manufacture, and even the display of all of the UHF channel numbers in a manner which is compatible with the display for the much smaller number of VHF channels is difficult to accomplish.
The introduction of voltage-variable capacitor or varactor tuners for the VHF and UHF bands to which a television receiver can be tuned has opened the way for electronic tuning of television receivers. This replaces the cumbersome mechanical turret tuners and allows greater flexibility in the design of the channel selection panel and in the location of tuner parts within the receiver cabinet. Even so, if the receiver is to be made capable of individual selection of any one of the 70 UHF channels in addition to the VHF channels, it has been necessary to provide a large number of individual tuning components. For example, in many prior art electronic tuner control circuits, it has been necessary to provide a separate tuning potentiometer for each of the 70 UHF channels if full capability of UHF channel selection is desired. This results in a relatively expensive tuner configuration requiring a large number of parts.

The commands are all locate right side and the tuning drawbar is a box which can be pulled out to tune channels.

The set features a modular robust chassis and weights a little.

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.

The set is fabricated by SEIMART IN 1977.

MAGNADYNE 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 (CRT TUBES AND TUBES)

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

Notes: 

S. Sacco - La Magnadyne di Sant'Antonio. La nascita, lo splendore, il declino e le lotte per la difesa dell'occupazione - Graffio, Torino, 2008, ISBN 88-95057-06-6

^ "L'azienda elettronica che produce televisori in crisi per mancanza di commesse Scatta la cassa integrazione alla Elcit Sant'Antonino: interessa 83 dipendenti su cento", Articolo del quotidiano La Stampa del 3 aprile 1997^{[collegamento interrotto]} ^ Dal sito haikellah.com ^ Dal sito haikellah.com