The MAGNADYNE ALFA BE1011 is a portable 12 inches B/W television with 4 programs preselection keyborad with potentiometric tuning search.
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.
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.
Power supply is obtainable both mains 220v and 12volt with special provided socket on rear side.
Mains supply features a voltage of 220volt, but after model the MAGNADYNE ALFA BE1022 YEAR 1974. have a voltage changer from 110volt to 240volt.
All commands are manual and located on topside.
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
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
NEOHM was a resistor fabricant and was part of the group
STAMPLAST
STAMFER
CIRSTA
FRIMAX
FINPLAST
VALVEX (CRT TUBES AND TUBES)
ELCIT died in 1998 by typically Italian Industry Destroy culture tradition (and , of course, chinese and turkish (super CRAP) basar !) and all workers and employee landed.......... on the street !!!!!!!!!!!!!
Notes
<Readings>
- 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
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