Car radio
A car radio is a radio receiver that was developed for installation in a motor vehicle . For this purpose, it is usually designed for an operating voltage of 12 V (24 V for trucks) and has a standardized housing or a housing that is adapted to the vehicle type. Car radios have to be particularly compact and insensitive to vibrations and temperature fluctuations, which rules out the use of home radio receivers in vehicles. Many devices can also play back sound carriers such as audio CDs , USB sticks or (only rarely) compact cassettes . In 2009, Blaupunkt presented the first internet car radio.
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properties
Current radios can receive radio stations on VHF and medium wave , some also long or short wave . There are already isolated devices for receiving digital radio ( DAB ). An RDS decoder is usually part of the equipment to provide better information to the driver . More powerful models offer a TMC display or use a second tuner to receive a traffic information station . A navigation system can also be integrated. Anti-theft protection using coding is common today .
From the end of the 1960s to the beginning of the 21st century, devices with an integrated compact cassette drive that were mostly priced higher were on offer. Even before that, there were radios with players for 8-track cassettes in the USA , but these were replaced by compact cassettes. From the 1980s onwards, the audio CD replaced the music cassette. At the same time, more extensively equipped car radios with cassette players came on the market, to which a model-specific CD changer with up to eighteen compact discs in a magazine could be connected. The changers could be installed anywhere in the vehicle, usually in the glove compartment or in the trunk, and were operated via the radio. Many devices from the mid-2000s can also read MP3 CDs or DVDs . There are also connections for audio input, USB or sockets for SD or MMC cards. Due to the increasing spread of electronic storage media, more and more devices without CD drives have been establishing themselves in the entry-level area since the 2010s. MiniDisc players , on the other hand, could not prevail .
In Europe , over-the-counter car radios are usually offered in a standardized housing size that can be installed in the vehicle in the appropriate cutouts in the center console. In contrast to this, factory-installed car radios, which may be equipped with a navigation system, are now integrated directly into the center console of most automobile manufacturers . The higher installation position is intended to bring the device closer to the driver's field of vision in order to reduce the distraction caused by changing eyes. To increase traffic safety, a remote control is often provided near the steering wheel in factory-installed radios, which allows the radio to be set without taking your hands off the steering wheel.
Installation dimensions according to ISO
In the international standard ISO 7736 of March 1984, both installation spaces and connections for car radios for front installation in road vehicles are standardized. While a minimum of 160 mm is specified for the shaft depth, the front section with a width of 180 mm is set in two different heights (50 and 100 mm). This standard was implemented in April 1984 as DIN ISO 7736 in a national German standard and in September 1986 as ÖNORM ISO 7736 in a national Austrian standard (status: May 2013).
connections
The car radios common today usually have standardized connector plugs according to ISO 10487. This means that the devices can be installed in any vehicle with ISO connections, regardless of the manufacturer.
In recent years, many vehicle manufacturers have switched to connecting their factory-installed car radios to the vehicle's internal CAN bus using special connections . In these cases, the installation of car radios from another manufacturer is associated with additional costs, which are incurred in the form of special adapters.
Entrances
- Ground or negative pole for the power supply
- Continuous plus, 12 V voltage compared to ground, even when the vehicle is parked, required to be able to listen to the radio when the ignition is switched off or, with some devices, to save settings.
- Ignition plus , 12 V with the ignition switched on, enables the radio to be switched on and off automatically via the ignition .
- GALA input, receives the speed signal from the speedometer and enables speed-dependent volume adjustment
- Antenna input
- Lighting, 0–12 V, for day / night switching of the radio lighting or, on some models, setting the lighting intensity according to the lighting of the vehicle's on-board instruments.
There are two standards for antenna sockets in car radios, the older one according to DIN and the newer one according to ISO :
- DIN: Characteristic impedance: 150 Ohm; Pin diameter: 3.2 mm; Pen length: approx. 13 mm
- ISO: Characteristic impedance: 50 ohms; Pin diameter: 2.5mm; Pen length: approx. 5 mm
In addition, there are often other connections for CD changers , hands-free kits , remote controls and external music sources. If there is no connection for external sources, an adapter cassette can be used. Since 2006, mini-transmitters have also been approved in the VHF range that transmit audio signals (for example from an MP3 player) to the car radio via radio. However, there are also devices that feed the audio signals into the antenna cable by means of RF modulation. Adapters are also offered especially for original car radios that emulate a CD changer in order to connect a storage medium with MP3 files or an AUX source.
More modern car radios often also have an AUX input on the front or back so that external sources such as MP3 players can be connected directly via cable. This is often implemented in the form of a 3.5 mm jack socket on the front, sometimes also on the back with the help of a cinch connection.
Outputs
Most modern car radios have four loudspeaker outputs with a power of approx. 15 watts RMS. Many manufacturers indicate the significantly higher music output, for example (4 × 50 watts), but this output is not standardized and therefore leaves a lot of room for interpretation. In the car hi-fi sector, external power amplifiers are often used in order to achieve higher performance. This is connected with a cinch cable to the preamplifier output of the radio (English: "Pre-Out"). Factory-installed car radios usually do not have a preamplifier output, but retrofit radios, depending on the equipment, are equipped with up to six of these outputs, which have a voltage level of approx. 1.5 to 7 volts. Higher output levels promise interference-free signal transmission. In order to still be able to connect an amplifier to a car radio without a pre-amplifier output, a so-called "high-low adapter" can be used. Such adapters reduce the voltage from the speaker output of the radio to give a signal strength similar to that of a pre-amplifier output.
speaker
Built-in loudspeakers with an impedance of 4 Ω have become established in cars . These can at 12 V of the electrical system without boost converter convert more power in sound pressure as a loudspeaker with a higher impedance at the same voltage . In the 1960s and 1970s, a single moving coil loudspeaker was installed ex works, mostly in the center, under the windshield. With the introduction of stereophony in the car, two loudspeakers were installed under the A-pillars , and later a second pair of loudspeaker chassis was also installed at the rear, next to or in the parcel shelf . Diameters of 10 cm were very common. The round chassis were very common in Europe and Asia, while oval 6 " × 9" chassis in the rear shelf, paired with smaller speakers at the front , became popular in the USA . In the 1990s, loudspeakers were increasingly installed in doors. The larger chassis made it possible to reproduce lower sound frequencies.
In the meantime, systems have established themselves in the larger vehicle classes, where woofers in the door are supplemented by tweeters at the height of the window edge. These can often be found in the dashboard, the mirror triangle or next to the door opener. This promotes a clearer stereo image. Additional, concealed woofers ("subwoofers") are also no longer uncommon. The rear speakers have become less important as a result.
Problems
Despite the identical-looking plugs according to ISO 10487 , the contact assignment is inconsistent.
For example, some car manufacturers swap permanent plus and ignition plus in the vehicle connector, which in this case results in radio malfunctions (in this example, the radio is constantly switched on, and the ignition plus, which is only intended as a signal line, has to take over the power supply of the radio, which can overload the circuit) .
The connection of the speed-dependent volume adjustment (GaLa) on the vehicle side is not always placed on the same pin in the connector. In order to rule out a malfunction of the brake or the anti-lock braking system (ABS) and its ASR / ESP extensions, this signal is generated separately from the speed-dependent ABS signal. For safety reasons, all electronic signals that are responsible for braking and are connected to it may not be used for any other functions in the vehicle. This means that if the GALA signal is missing in an older vehicle, this must not be taken from the ABS signal.
There may be other vehicle manufacturer-specific contact assignments for the ISO connector, which can lead to malfunctions in the vehicle electronics when an accessory radio is connected.
Thus, from a legal point of view, the incorrect installation of a car radio by yourself can invalidate the vehicle's operating license . Some vehicle manufacturers therefore prohibit self-installation of car radios in the legally binding operating instructions for the vehicles.
As the vehicle manufacturers continue to network their factory radios with the vehicle, replacing them with a radio from another manufacturer can also lead to the loss of functions that were previously only accessible via the factory radio (e.g. time setting, access to the on-board computer , Failure of the steering wheel remote control). Furthermore, the installation of the replacement device can be very complex and associated with additional costs due to adapters that may be required. The visual appearance can also be severely impaired because the factory radios are optimally integrated into the overall appearance due to their shape and appearance.
history
From 1920
In 1922 was in a Ford Model T in Chicago radio installed at the same time one was in England Daimler with a car radio from Marco Iphone Co equipped. In 1927, the first "Philco Transitone" car radio, industrially manufactured by Storage Battery Co., Philadelphia, was offered as an accessory by Chevrolet in the USA . Galvin Manufacturing Corporation (GMC) built the world's first commercially successful car radio in 1930. Developers were William P. Lear and Elmer Wavering . The 5T71 model cost between $ 110 and $ 130. Because of its heavy and voluminous design, the radio was given the name “ Motorola ”, a word created from motor (motorcar, motion) and ola (sound, wave, la ola) (according to other sources Brand one : “A combination of automobile and Victrola, the legendary gramophone "). The success was so great that it soon became a synonym for the manufacturer and for a car radio in the USA.
The first car radio in Germany was brought onto the market by Telefunken in 1925. It was an elongated version of the Telefunkon 3 home receiver , which was specially designed for installation in boats and automobiles. This “Sports Receiver 1925” was attached to the vehicle with a special spring construction.
At the 9th Great German Radio Exhibition in Berlin in August 1932 and at the 23rd International Automobile and Motorcycle Exhibition (IAMA) in February 1933, the Berlin radio telephone and apparatus factory Ideal AG (today Blaupunkt ) presented the "Autosuper AS 5" . The superheterodyne receiver (superheterodyne receiver or "Superhet / Super") for the medium and long wave range with five electron tubes was developed together with the ideal parent company Robert Bosch AG (a GmbH since 1937). It could be operated remotely from the steering column with Bowden cables and required its own anode battery or an additional converter for the anode voltage. The device had a volume of 10 liters and, at a price of 465 Reichsmarks, was, like the car itself, a luxury item, because in the waning global economic crisis in 1934, for example, B. a 1.3 liter Opel just under 2650 Reichsmarks. Adjusted for purchasing power in today's currency, this corresponds to approx. 11,900 euros for the car and 2,090 euros for the radio. H. depending on the reference value between 15 and 17.5% of the car price.
After tests during a Sahara expedition, a first series of 300 pieces was produced in a Bosch sample workshop. The antenna was laid as a strand on the headliner (which at that time was often made of fabric) or under the wooden door step boards. The Blaupunkt 4A75 device was introduced in 1933 for 325 Reichsmarks , which now fitted with all components including the loudspeaker in a 9.5 liter housing. A small chopper replaced the unwieldy anode voltage converter . The superhete had six electron tubes and seven circles . In 1934 Telefunken introduced the T540 for 353 Reichsmarks. In 1936 Blaupunkt introduced the 5A76 (six tubes / seven circles) for 332.75 RM, Körting the ASE 6340 in a version for 6 V and a version for 12 V car battery each for 420 RM and Telefunken the T655 for 450 RM Before, in 1938 the Blaupunkt 7A78 appeared with seven tubes and six oscillating circuits with shrinkage control and illuminated tuning scale. There are steel pipes used, the price was 330 marks. Sales of car radios then doubled compared to the previous year. Körting presented the AS7340 for 348 RM, Telefunken the T3877 for 338 RM, and Philips offered devices with internal or external loudspeakers for 6 or 12 volts. In 1939 the Blaupunkt 7A79 was available for 330 RM, the Lorenz AS39 for 298 RM, the Telefunken IA39 for 325 RM. Philips also had devices with internal and external loudspeakers for operation with 6 or 12 volts in their range.
From 1940
After losing its operations in the east, Blaupunkt had already moved to Hildesheim at the beginning of 1945 and presented the 5A649 model in 1948 , which could be built into the dashboard with all its components and thus dispense with the Bowden cable transmitter setting previously used. The company Becker (today: Harman Becker Automotive Systems ), founded by Max Egon Becker in Pforzheim in 1949 , presented the medium wave device Autophon (5 tubes / 6 circles) and the additional long and short wave receiving aerophone to the customer Daimler-Benz , and a long business relationship started with Mercedes-Benz . In 1951, Becker introduced station buttons with inductive tuning ( variometer ) with the Nürnberg device .
In 1952 the A52KU and the A520KU (with or without pushbuttons) from Blaupunkt appeared, which could also receive the VHF radio introduced in Germany in 1949. In 1953, the VHF range (in mono ) and the automatic station search with the Becker Mexico were introduced. Blaupunkt presented the improved A53KU . In 1954 Blaupunkt presented the Cologne model with automatic station search. 1957 began the use of transistors in the output stage and in the DC voltage converter (for the remaining electron tubes). In 1958, a 17 cm record player Automignon from Philips to be installed under the instrument panel appeared in order to meet the desire for individual music design in motor vehicles.
From 1960
The first car radio to be fully equipped with transistors was introduced by Philips in 1961, followed by the Becker Monte Carlo in 1963 . Grundig followed suit with the AS40 in 1965 . In 1968 car radios with built-in cassette players appeared (Philips).
From 1961, Braun produced its portable radio models “T52” and the following in Frankfurt am Main. There was a bracket for cars. So you could save yourself the relatively expensive car radio and at the same time use your radio outside the vehicle.
In 1969 Blaupunkt brought the first FM stereo car radio ( Frankfurt Stereo ) onto the market. Becker presented the stereo cassette radio Mexico Olympia Stereo (with mono FM reception and stereo cassette playback) and the FM stereo radio Europa Stereo . At the 1973 radio exhibition, Blaupunkt presented the Berlin electronic full stereo cassette device , which was available from May 1974. Operation was via a separate gooseneck , which was supposed to move the controls closer to the driver.
On June 1, 1974, the Automobile Driver Broadcasting Information System (ARI) was put into operation, which enabled the automatic detection of traffic reports in the car radio. The year before there were ARI additional decoders from Blaupunkt, followed by car radios with an integrated ARI part. In 1975 the Becker Mexico Cassette full stereo reverse was released for cassette operation with auto reverse . It was the last Becker device in a classic design with a tuning scale and pushbuttons. In 1976 the two Becker devices Europa Kurier and Monza Cassette Kurier came on the market, where Kurier stands for the ARI receiver. In 1977 Blaupunkt launched the Koblenz CB with an integrated CB radio that was housed in a DIN housing. In 1979 the Becker Mexico Electronic was controlled with a microprocessor . Blaupunkt supplied the Bamberg QTS with an LED 7-segment digital display for the reception frequency and a quartz tuning system.
From 1980
In 1980 Becker dispensed with rotary knobs for volume and tuning in the Mexico Cassette Electronic 385 , and the car radios could be removed to protect against theft. In 1982 Blaupunkt introduced the Berlin IQR 83 , with a multi-line LCD display, automatic PCI transmitter identification and voice output. Grundig launched the WkC3867VD with a cassette drive and LCD digital display on the market. Most car radios have since offered three options for setting stations: manual tuning, station buttons and station search . Only the Becker Mexico Cassette Electronic 385 offered the fourth option of typing in the frequency digits as with a pocket calculator . In 1983 integrated CD players were introduced instead of cassette drives, in 1985 the devices with integrated CD players from Philips and Becker (the Mexico Compact Disc 860 ), later supplemented with CD changers . Car radios could be protected against theft with a code number, and Philips devices looked for the best possible transmitter within a transmitter chain. In 1987 Becker Mexico Diversity appeared with two receivers, one for radio reception and the other for monitoring a traffic radio station. A short time later, Blaupunkt followed suit and named this system Travel ARI. On April 1, 1988, the Radio Data System (RDS) for the automatic processing of traffic reports in the car radio, transmission of station names and other additional information was put into operation. The first car radio with RDS was the Volvo SR-701 radio, available for an extra charge in Volvos. The first devices displayed the station name (RDS-PS) and automatically switched to the best frequency (RDS-AF), for example the Blaupunkt Montreux RDR 49 . In 1989 it was possible to remove the front panel of the radio from Grundig devices as protection against theft; Blaupunkt used a keycard for this.
Since 1990
In 1991 RDS-EON was used, i. In other words, traffic information could also be received if the set station does not broadcast traffic information, but uses RDS-EON to inform which other one is doing it. In 1992, with the Blaupunkt Stockholm, the TIM (Traffic Memo) option was made available, which also records traffic reports when the driver is absent and the radio is switched off. The maximum recording time was four minutes. The linking of navigation systems to the car radio began in 1993 , later they were integrated directly (Philips CARIN (Car Information and Navigation System)). In 1997 Blaupunkt presented radios with DAB reception and integration of mobile phones . The Traffic Message Channel (TMC) was now also able to display traffic news independently of the radio program on the radio screen via RDS. With the Traffic Star, Becker presented an integrated combination of car radio, CD player and navigation system.
From 2000
In 2001 there was a car radio from Blaupunkt with MP3 decoder and multimedia card slot. In 2003, the car radio with MP3 decoder and multimedia card slot could then also record the received radio program. 2006 brought Sony car stereo MEX-1GP out in the control unit, enter 1 gigabyte large Flash memory is integrated. The control unit can be connected to the PC using a USB cable to copy MP3 music files.
In the higher price ranges you will also find car radios with an integrated DVD player , mostly with a TFT screen, on which films can be viewed. Most of these devices are equipped with a navigation system. Depending on the equipment, additional screens (for example in the rear of the vehicle) can be connected. It is often also possible to connect a DVB-T receiver module or a game console via an AV input, for example .
More expensive, modern car radios also offer numerous other connection options, for example an input for a reversing system , which switches on automatically when reverse gear is engaged , for example . In addition, more and more car radios with Bluetooth interfaces are available whose function profiles allow hands-free calling or access to media files from cell phones or the like.
From 2010
With the increasing use of smartphones and navigation systems , multifunctional devices, also known as naviceivers or moniceivers , became widespread, first in luxury- class vehicles and over time in all vehicle classes . They have practically all the functions of normal smartphones or tablets, i. H. Radio, playback of different media, navigation system, hands-free system, coupling via Bluetooth, Internet connection, etc. Some of the devices are also operated with Android so that apps can be exchanged or additionally installed (e.g. the app for media playback).
These multifunctional devices usually have a screen or are equipped with several control elements so that they have an installation height of a full DIN slot . In newer cars, the installation slot was also provided with a cover to better adapt the radio to the design of the rest of the center console. In such cases, the expansion is sometimes more complex because the aperture u. U. is screwed to the center console.
Transmission routes
The broadcasts can be transmitted terrestrially (analog or digital), via the Internet or satellite . The latter is mainly common in North America.
Broadcasts for car radios
Specific radio programs are broadcast for the car radio . They are intended to reach the car-driving commuters during rush hour . The prime time is between 06:00 and 09:00 and 16:00 to 18:00 and is known as " Drive Time ". Programs that get a slot in that period can expect the highest ratings . In between is the "daytime" period. Any program outside of this core program area only reaches a relatively small part of the audience. During the "drive time", target group-specific programs are broadcast on the radio. In addition to music, these include traffic radio , frequent time announcements or specific radio advertising such as car advertising; Distracting or lengthy interviews are avoided . The interval between news broadcasts , which often follow every half an hour, is also typical . In the US, too, drive time is an important part of daily news broadcasts, especially since it is the only time when radio news listeners exceed TV news.
See also
Web links
Individual evidence
- ↑ a b c d e f g h i j k l m n o p q r s history of the car radio
- ↑ Günter F. Abele: Radio Chronicle - From the post-war period to the present. Füsslin Verlag, Stuttgart 2003, ISBN 3-9803451-8-1 , p. 225
- ↑ These figures were based on the template: Inflation determined, rounded to 10 EUR and apply to the previous January
- ^ The first car radio from Ideal / Bosch ( Memento from November 13, 2006 in the Internet Archive )
- ↑ a b c d e f g h i Company history Blaupunkt company / innovations ( Memento from December 7, 2006 in the Internet Archive )
- ↑ a b c d e f g h i j k l m n o p q r s t u Detailed history of the car radio
- ↑ Blaupunkt 5A649 on radiomuseum.org
- ↑ a b c d e f g h History of Becker car radios
- ↑ Car radio and RDS
- ↑ Stewart Clark Rogers, Marketing Strategies , 2001, p. 104
- ↑ Mosheh Tsuikerman, Media Policy History , 2003, p 261
- ^ Brad Schultz, Broadcast News Producing , 2004, p. 124