IRRADIO MOD. 2022/A CORALL 22" YEAR 1981.

The IRRADIO MOD. 2022/A CORALL 22" is a 22 inches color television with 16 programs PLL synthesized tuning system and infrared remote control. tuning system employs a frequency synthesizer system for establishing the tuning of the receiver, featured with a Microcomputer driven synthesis system.

The system employed in the tv permits utilization of a frequency synthesizer tuning system which correctly tunes to a desired television station or channel even if the transmitted signals from that station are not precisely maintained at the proper frequencies even in combination of a fine tuning adjustable by the user.
Accordingly, it is an object of this invention to provide an improved tuning system for a television receiver.
It is an additional object of this invention to provide an improved frequency synthesizer tuning system for a television receiver.

PLL SYNTHESIZED TUNING System Concepts:

INTRODUCTION Digital tuning systems are fast replacing the conventional mechanical systems in AM FM and television receivers The desirability of the digital approach is mainly due to the following features * Precise tuning of station frequencies
* Exact digital frequency display
* Keyboard entry of desired frequency
* Virtually unlimited station memory
* Up down scanning through the band
* Station ‘‘search’’ (stop on next active station)
* Power on to the last station
* Easy option for time-of-day clock In addition
" recent "developments in large scale integrated circuit technology and new varactor diodes for the AM band have made the cost-benefit picture for digital tuning very attractive System partitioning is extremely important in optimizing this cost-benefit picture as will be discussed.

SYSTEM DESCRIPTION
A simplified block diagram of a typical digitally tuned receiver is shown in Figure 1 Notice this receiver could be one for AM FM marine radio or television it makes no difference The frequency synthesizer block generates the local oscillator frequency for the receiver just as a conventional mechanical tuner would However the phase-locked-loop (PLL) acts as an integral frequency multiplier of an accurate crystal controlled reference frequency while the mechanical type provides a continuously variable frequency output with no reference Some method of controlling the value of the multiplier for channel tuning must be provided The other RF IF and audio video circuitry will be the same as in the mechanical tuning method There are many different ways to partition the frequency synthesizer system to perform the digital tuning function................



Was first model series from IRRADIO manufactured by NORDING using a SIEMENS SDA series Ucontroller for the PLL synthesizer tuning system, and A PIL VIDEOCOLOR TUBE. The chassis is a multi modular type.A microcomputer control system is described for effecting channel tuning and function selection in a television receiver. The system will respond to commands entered by a set of controls at the television receiver or to remote control commands received at the television receiver. A channel number display is also provided whereby the channel number of a station currently tuned is displayed. A microprocessor within the system is programmed to validate control information received from an operator either by remotely generated commands or by controls located on the television receiver. Operator supplied information is processed and implemented by the microprocessor control system to effect control over the television receiver.
Microprocessor technology has recently provided circuit designers with a new basic design component. The microprocessor is capable of duplicating many functions heretofore realized with the use of large scale computer systems. The microprocessors have the advantage of being small, low power consumption devices capable of being programmed with instructions for executing mathematical algorithms on data supplied to the microprocessor. The microprocessor, when properly programmed, will execute a set of instructions providing output data during execution which may be used to control a process or apparatus.
The control of television receivers has heretofore required separate circuits for effecting channel selection, function selection and level setting, and remote control. With the microprocessor it has become possible to control these performance aspects with a single preprogrammed microprocessor and suitable input/output circuits. Data indicating the selection of a new channel to be tuned or a function to be controlled by an operator of the television receiver may be supplied to the input port of the microprocessor. This data may be supplied from a set of hand controls or a transducer for detecting remotely generated commands. Remote control systems presently incorporated in many television receivers provide operation of a television receiver by transmitting information bearing ultrasonic sound waves or infrared light waves to the television receiver. These waves when received at the television receiver are decoded into an electrical signal for effecting the change in channel tuning or function level. The microprocessor has the capability of validating this electrical signal and performing all decoding pursuant to preprogrammed instructions. These instructions, when executed by the microprocessor, generate a digital signal for effecting the desired channel change or function level change.

The set is build with a Modular chassis design because as modern television receivers become more complex the problem of repairing the receiver becomes more difficult. As the number of components used in the television receiver increases the susceptibility to breakdown increases and it becomes more difficult to replace defective components as they are more closely spaced. The problem has become even more complicated with the increasing number of color television receivers in use. A color television receiver has a larger number of circuits of a higher degree of complexity than the black and white receiver and further a more highly trained serviceman is required to properly service the color television receiver.
Fortunately for the service problem to date, most failures occur in the vacuum tubes used in the television receivers. A faulty or inoperative vacuum tube is relatively easy to find and replace. However, where the television receiver malfunction is caused by the failure of other components, such as resistors, capacitors or inductors, it is harder to isolate the defective component and a higher degree of skill on the part of the serviceman is required.
Even with the great majority of the color television receiver malfunctions being of the "easy to find and repair" type proper servicing of color sets has been difficult to obtain due to the shortage of trained serviceman.
At the present time advances in the state of the semiconductor art have led to the increasing use of transistors in color television receivers. The receiver described in this application has only two tubes, the picture tube and the high voltage rectifier tube, all the other active components in the receiver being semiconductors.
One important characteristic of a semiconductor device is its extreme reliability in comparison with the vacuum tube. The number of transistor and integrated circuit failures in the television receiver will be very low in comparison with the failures of other components, the reverse of what is true in present day color television receivers. Thus most failures in future television receivers will be of the hard to service type and will require more highly qualified servicemen.
The primary symptoms of a television receiver malfunction are shown on the picture tube of the television receiver while the components causing the malfunction are located within the cabinet. Also many adjustments to the receiver require the serviceman to observe the screen. Thus the serviceman must use unsatisfactory mirror arrangements to remove the electronic chassis from the cabinet, usually a very difficult task. Further many components are "buried" in a maze of circuitry and other components so that they are difficult to remove and replace without damage to other components in the receiver.
Repairing a modern color television receiver often requires that the receiver be removed from the home and carried to a repair shop where it may remain for many weeks. This is an expensive undertaking since most receivers are bulky and heavy enough to require at least two persons to carry them. Further, two trips must be made to the home, one to pick up the receiver and one to deliver it. For these reasons, the cost of maintaining the color television receiver in operating condition often exceeds the initial cost of the receiver and is an important factor in determining whether a receiver will be purchased.
Therefore, the object of this invention is to provide a transistorized color television receiver in which the main electronic chassis is easily accessible for maintenance and adjustment. Another object of this invention is to provide a transistorized color television receiver in which the electronic circuits are divided into a plurality of modules with the modules easily removable for service and maintenance. The main electronic chassis is slidably mounted within the cabinet so that it may be withdrawn, in the same manner as a drawer, to expose the electronic circuitry therein for maintenance and adjustment from the rear closure panel after easy removal. Another aspect is the capability to be serviced at eventually the home of the owner.

IRRADIO is an Italian manufacturer founded in Milan (Italy) in 1939.

His contribution to the growing of electronic consumers market is alive even todays.
The ownership is the group of Melchioni Electronics which is even an Italian firm from Milan.
The products of IRRADIO are variing from radios, TV, CD Players, Telephones...............