Braun Sk55 Manual

Forums: 

Braun Sk55 Manual

ENTER SITE »»» DOWNLOAD PDF
CLICK HERE »»» BOOK READER

File Name:Braun Sk55 Manual.pdf
Size: 1564 KB
Type: PDF, ePub, eBook

Category: Book
Uploaded: 21 May 2019, 13:53 PM
Rating: 4.6/5 from 586 votes.

Status: AVAILABLE

Last checked: 6 Minutes ago!

In order to read or download Braun Sk55 Manual ebook, you need to create a FREE account.

Download Now!

eBook includes PDF, ePub and Kindle version

✔ Register a free 1 month Trial Account.

✔ Download as many books as you like (Personal use)

✔ Cancel the membership at any time if not satisfied.

✔ Join Over 80000 Happy Readers

Braun Sk55 ManualNOTE To view PDF files the latest version of the official acrobat reader is required. The PDF files are provided under strict licence. Reproduction without prior permission or for financial gain is strictly prohibited. This website is not affiliated with or sponsored by Braun. Supertramp Crime Of The. How Come A Sl-q303 Is Lighter. Help - Sony Ps4300 Cartridge Close-ups - Show. Pickering V-15 For Dual 1219 Manticore Mantra Query Sme Vta Ring. Please do not offer the downloaded file for sell only use it for personal usage. Looking for other manual? For this no need registration. May be help you to repair. You could suffer a fatal electrical shock. Instead, contact your nearest service center. Note! To open downloaded files you need acrobat reader or similar pdf reader program. In addition, Also some files are djvu so you need djvu viewer to open them. These free programs can be found on this page: needed progs If you use opera you have to disable opera turbo function to download file. If you cannot download this file, try it with CHROME or FIREFOX browser. Translate this page: Relevant AUDIO forum topics: horeles ventillator epites subwofer erositore evekkel ezelott epitettem egy subwofer-t, Piret Endre okleveles hangmernok terve alapjan, kompand lada. 30 cm-es videoton hangszorokkal.DELCO autoradio Model:16169175 frekvencia raszter atallitasa Szevasztok! Koztudott, hogy az USA osztas szerint a paratlanra vegzodo frekvencia a beallithato. Megoldas letezik, mert van latotavolsagon belul egy pontosan ilyen evjaratu keszulek ami mar az europai normaknak megfeleloen mukodik. Ezert, ha tudtok, ehhez a tipushoz szeretnek konkret segitseget kerni. A mellekletben szereplo fenykepek nem errol a keszulekrol keszultek, tehat a szeria szam nem egyezik.Dr.Tavado Behringer djx750 kevero kulonleges hiba. Szep napot mindenkinek! Nemreg vettem egy behringer djx750-es keverot hasznaltan es erdekes dologra lettem figyelmes hasznalatkor.http://studiowlt.com/userfiles/brinly-lawn-sweeper-manual.xml

    Tags:
  • braun sk55 manual, braun sk55 service manual, sk55 braun manual, braun sk55 manual, braun sk55 manual pdf, braun sk55 manual download, braun sk55 manual free, braun sk55 manual instructions.

Termeszetesen jol sikerult az uzlet amikor megvettem es kiprobaltam pont nem jott elo a hiba:D. Szoval van olyan hogy bekapcsolom es nemelyik csatorna feloldalasan szol(egyik fele megy a masik nem).Arra gondoltam hogy ez hiba,de sajnos rajzom nincs hozza hasonlo a djx700-ashoz ezert azon nezelodtem,de nem jottem ra a problemara.Ma viszont bekapcsolom a keverot ismet es azok a csatornak amik rosszak voltak,ismet szolnak rendesen.Hozza kell meg tegyem,hogy mikor nem szol a masteren az egyik oldal akkor a terhatas kapcsolo gombal vagy effekt bekapcsolo gombal elo lehet hozni a masik oldalt ami nem szol,de amint kikapcsolom akkor eltunik az az oldal.Szoval ebben szeretnek segitseget kerni,talalkozott-e mar valaki ilyennel esetleg tudja mi lehet vele?Koszonom Krisztian EONON E1015 feliratu autoradio,tv, DVD (tovabbi hasfajas) udv:van egy EONON E1015 feliratu kepernyos szerkezet, nem ismerem a bekoteset, a tanyan egyik sem hasonlit. Sem kivul, sem belul nincs sehol felirat, szamozas. Ami biztos, a jobboldali 4x2 csatlakozo a vegfokra megy(TA 8264). Marad meg 6 db bekotott csatlakozo, amibol 2 db az el.antennat es erositot kapcsolja. Ezekbol meg egy biztos, az also sor balrol a 4. a test. A tapbemenethez kozel van egy szakadt APM 3095 p-FET, ezt tudom potolni. A felnyilo kepernyo mogott van a dvd berako nyilas. Maga keszulek 1 DIN-es meretu. Ismeri valaki a bekotest? Balint Similar manuals: You can write in English language into the forum (not only in Hungarian). Something went wrong.This amount is subject to change until you make payment. For additional information, see the Global Shipping Program terms and conditions - opens in a new window or tab This amount is subject to change until you make payment. If you reside in an EU member state besides UK, import VAT on this purchase is not recoverable. For additional information, see the Global Shipping Program terms and conditions - opens in a new window or tab Delivery times may vary, especially during peak periods.http://saldanha.in/pharma/admin/userfiles/brinno-garden-watch-camera-manual.xml Learn more - opens in a new window or tab The item may have some signs of cosmetic wear, but is fully This item may be a floor model or store return that has been used. See the seller’s listing for full details and description of any imperfections. If you don't follow our item condition policy for returns, you may not receive a full refund. Refunds by law: In Australia, consumers have a legal right to obtain a refund from a business if the goods purchased are faulty, not fit for purpose or don't match the seller's description. More information at returns. All Rights Reserved. User Agreement, Privacy, Cookies and AdChoice Norton Secured - powered by Verisign. Recently, thanks to the kindness of Michael Hohl, I acquired a wonderful Braun SK55 radiogram from the early 1960s. Useful Sources. Woodlands Junior School This is a Braun SK-55 I believe. It has been stored badly and has suffered some damp. Finish is poor, take a close look at the photos which 8 items BRAUN SK 55 radio turntable DIETER RAMS Bauhaus SK55.Braun SK55, the arrival of mainstream modernism in consumer product design. The Bauhaus school of Ulm Size 58x24x28 cm. BRAUN SK55 The April Fools Soundtrack Jack Lemmon, Catherine Deneuve 20 Mar 2009 Braun SK55, the arrival of mainstream modernism in consumer product design.Useful Sources. Woodlands Junior School 1 May 2011 BRAUN SK55 PHONO RADIO RECORD Dieter Rams Hans Gugelot. Gestaltung ULMER SCHOOL, a progressive design academy with links to Braun that BRAUN REGIE 510, BRAUN REGIE 550.Log in We need to verify that you are not a robot generating spam. This has always been one of my favorite design icons and in my opinion, is the most crucial product to Braun’s history. Sure, you could argue that something like the Thonet No. 14 chair is a more influential product but in the consumer electronics world, this is the apex. The SK series by Braun is our On the Origin of Species.https://congviendisan.vn/vi/3g-router-huawei-e960-manual It's the foundation of everything we believe today as creators of objects and experiences. - Braun was founded by Max Braun in 1921 and became one of Germany’s greatest radio manufacturers. In 1951, Max Braun passed away at the age of 61 and passed on the company to his sons Artur and Erwin Braun. This is when things got really interesting. He built a company that valued design and hired people like Wolfgang Schmittel to revamp the company’s graphical voice and marketing. It felt like a piece of the puzzle was missing though, and after their father passed away, Erwin and Artur began thinking about how they could change the physical appearance of their products. Hans Gugelot and Dieter Rams were responsible for designing what the company calls a “Phonosuper”; a radio combined with a record player. During this era, similar products were constructed completely of wood and lavishly decorated with purely decorative ornaments. Braun wanted to rid of these superfluous elements and design products, not furniture. Gugelot and Rams designed a product that was constructed almost entirely from powder coated sheet metal with tasteful elm panels. Every detail had to have a functional purpose and it was designed to pioneer a new contemporary language of design. There was one problem though. The hood of the prototype unit was made from sheet metal and had the tendency to rattle in higher volumes. Dieter Rams suggested the use of a plexiglass cover and that’s when history was forever altered. Keep in mind that most people were used to using wooden, armoire-like devices. The SK4 was launched in 1956 and received universal praise from consumers. It was fresh, like a glass of ice water in a desert of terrible design. The SK4 scared the competitors so much that they gave it the dismissive nickname of “Snow White’s Coffin” - which only made the innovative product more memorable.http://www.indianantique.com/images/braun-series-7-790cc-manual-pdf.pdf Dieter Rams ( whom I've had the privilege to meet a couple of times ) became the head of design in 1961 and changed the path of industrial design for the rest of the world. The company became the epitome for honest, functional products and the principles set then are still foundational to helping us fathom what good design truly is. The company introduced many successors to the SK4, and with each iterative update, created a more refined product. The model I ended up purchasing is the latest iteration, and the last radio-audio combination the company produced, the SK55.You immediately realize that this is the work of a master. One of the catalysts for Braun’s aesthetic refresh was the desire to cleanse the ethical and aesthetic catastrophe of the Nazi era. It’s no surprise that the SK55 comes off as being pure, warm, and honest. The construction methods are simplistic by today’s standards but are done with great precision. Despite being 51 years old, my SK55 still feels like new and has the solidity that’s present in proper German products. Good design is durable. It looks contemporary even after all these years and is a visual cue Apple has referenced in many of their products. The cover also has the ability to make the SK55 look more precious - like a museum exhibit, it proudly displays its internals while reminding you to treat it with respect. I think the SK55 is one of the best examples of this. There is a concise organization, restraint and functionality to its layout that reminds me of Japanese architecture. That’s not to say that it’s making a direct reference to anything though; it’s more of a translation of Japanese philosophies as expressed by a German designer using German values. It’s a beautiful thing. This is what makes the SK55 so beautiful to witness; it feels like modern furniture but is clearly something that is high tech.https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1628496140f383---bunn-ultra-2-programming-manual.pdf It is the embodiment of Braun’s desire to create “faithful servants” - products that disappear into the background when you aren’t using them. The SK55 is subdued, inconspicuous and blend into the home seamlessly. Both perform similar duties and have similar approaches to design. Playing music has become the trivial act of moving a single finger. This is obviously quite different, and the ritual starts with opening the coffin’s clear cover. Super slim and integrated perfectly into the wooden sides. The hinge and screws both have a similar finish, reducing visual clutter. Mine have been compressed over time and don’t do much though. Ornamentation is nowhere to be found and everything is designed for ease of use. SK products before this used light grey controls that I find looks prettier but these “graphite” controls were employed to increase contrast - and therefore usability. The first one powers on the device, the second puts it in turntable mode and the right three are for various radio bands, with the last one being FM. The knob on the right with the orange-red dot controls the radio frequency. Notice how the dot’s colour correlates with the indicator needle, an effort to help the user make the functional connection. From top to bottom: treble, bass and volume. It doesn’t require an external antenna and seems to get pretty good reception without one. I particularly enjoy the clear treatment of typography and fine linework that indicates a sense of precision. In our digital world, all of our inputs are translated into movement of pixels. There’s something very satisfying about turning a knob and that getting translated into the creamy movement of a needle. The tone arm is brilliantly pure in design and is made from a bent aluminum tube. The aluminum has a gorgeous matte texture that’s similar to what’s found on the Apple iSight. This is the second act in this ritual. It’s an earlier technology and has more distortion than later developments.www.cnlpzz.com/d/files/comenda-lb215-glasswasher-manual.pdf The tone arm is lifted and placed on the record using the arm that sticks out of its plastic shell. Notice how it’s made of the same graphite plastic as the knobs and buttons, an indication for the user that it’s something you interact with. The SK55 is the first of the SK series to use a simple rubber mat instead of small rubber protrusions. It’s not as aesthetically pleasing but the decision was a functional one. I enjoy watching the delicate maneuvers that occur here. This was one of the first Braun product to remove the 78 rpm mode, which was used for older shellac records. I found it to be inadequate in providing enough weight to prevent occasional skipping. I’m no turntable expert but I do realize that the SK55 wasn’t made to play modern records of today. The SK series was far removed from being high fidelity from the beginning though. When the SK4 was first introduced, Braun was more focused on luring consumers with progressive design than audio fidelity, which ended up being a successful plan for the company. Once the company made their name with these mass market products, they later expanded their lineup to include professional grade audio equipment. I never intended on using this for critical listening, but the simple fact that I’m using a Braun SK55 is enough to make the music sound sweeter than anything I’ve ever listened to. It’s simply not able to produce enough detail or low end grunt. No surprise though. Funny how a bar can be a “big change”. Reminds me of the way Porsche refines their cars. It’s made from cardboard and has warped and scratched over the many years. The straightforward grid-based ventilation holes are a very “Braun” touch. There’s a small plastic window that shows whether you have the unit set to 220V or 110V. A nice touch. Once again, weathered with time. There’s a ton of empty space in there and it looks like the size of the SK55 was driven by the height of the speaker and the size of records more than anything.https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16284962836134---bunn-tf-server-manual.pdf I’ve tried connecting external speakers but the output fidelity doesn’t seem that great. I’ve reached my peak. This is it, the SK55 is my all time favorite product and there’s nothing in the world more important for me to share on this website than this. The Braun SK55, or the SK4 to be more specific, is in my opinion, the most important product in Braun’s history and therefore the most important product to the design of electronics today. It started everything. It’s what smacked us in the face and told the world that everything we were making was poorly thought out and conceived. We still live in its ethos and still have so much to learn from it. My primary reason for my recent wave of older products was to show how little we’ve progressed, or actually, regressed philosophically in the past decade. The SK55 is much older though. It’s 51 years old and has a level of purity and honesty that exceeds what we do today. I think that’s a bit embarrassing. I mean, look around you, we simply make so much garbage. When will we learn? When will we stop making shit. Good design is innovative makes a product useful aesthetic helps understand a product unobtrusive honest durable consequent to the last detail concerned with the environment as little design as possible Back to purity, back to simplicity. The pared-down designs he created during his career-spanning tenure at the German electronics company, Braun, began with his wall-mounted 606 Universal Shelving System intended for the company’s new, modern offices. His many innovations as the leader of the design team at the company paved the way for a new generation of designers focused on simplicity and practicality, including Apple’s Jonathan Ive. Rams was not only ahead of his time when it came to aesthetics; the designer has long been an advocate for the “end to the era of wastefulness,” promoting design that is as environmentally friendly as it is easy to use.https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16284963d499a1---bunn-thermofresh-owners-manual.pdf By continuing to use the forum you conform your acceptance of these. If you are not happy to accept these you must stop using the forum and delete our cookies from your browser. Everything seems to work, the light lights up, the turntable platter spins, the tubes glow but there is no sound coming from the speaker. Any suggestions or insights would be greatly appreciated. Here are some things that might be useful to know to diagnose the issue: - I have all of the right cords to convert the American 110 volt 60 Hz to the European 220 volt 50 Hz. I have a converter to turn the American 110 volt 60 Hz into a 12 volt car cigarette lighter outlet and then from that I have a sine wave inverter the outputs 220 volt 50 Hz power. This works well for my other Braun SK 5 so it should work for my SK 55. This means that the issue isn't just a problem with the record player or just a problem with the radio, there must be some issue with getting the sound out of the speaker. - I tried adjusting the volume and the treble and bass knobs but still no sound. This means that I don't just have the volume all the way down. - The record player spins at the right speed and when I place the needle on a record I can hear the music faintly as the record vibrates the needle but still there is no sound from the speaker. This means that the turntable and needle work. - I replaced the EL84 amp tube twice. I replaced the EABC 80 tube and the ECC 85 tubes also. This means it is unlikely that the tubes are broken. - To test the speaker I attached some old iPod earbud headphones to my iPhone and played the music and heard the music on the earbuds. Then I cut the earbuds off and exposed the wires. I opened the Braun SK 55 and touched the exposed headphone wires to the speaker inputs and the music from my iPhone came out of the Braun speaker. This means that the speaker isn't broken. Thanks for any words of advice!The most obvious things to look for would be to make sure you do have high voltage.www.cndasion.com/d/files/comenda-lb200-manual.pdf Eliminating the most obvious will allow you to eventually track down the problem.It would be worth checking if the switch is faulty, or just dirty contacts. FrankDo you think the switch could be inside. The Ebay seller also shipped me a cord that on one end plugs into the auxiliary input on the back of the Braun SK 55 and on the other end has a standard headphone plug. I connected my iPhone to the SK 55 with this cord but no music comes out of the speakers. So if the switch is looking for an auxiliary input and the connection to the speaker is working then this should make the music come out.The most obvious things to look for would be to make sure you do have high voltage. Eliminating the most obvious will allow you to eventually track down the problem. I assume I would need a special measuring device. Assuming the power was enough for the turntable but not enough for the amp then what would be my next step. Would I have to start replacing parts?I have not seen one of these sets or even a photo, I just found the circuit on the web and noticed the switch. FrankI assume I would need a special measuring device. Would I have to start replacing parts? You first need to establish if you have high voltage or not, from there you will get down to the problem, a bad capacitors, an open power resistor. It could be a small coupling capacitor (happens often with some German radios, or any old radio for that matter.I have looked in the service data at the top of the page and could not find this model. If I have missed it, mods, please delete this post and link to the service data. Frank. Specialising in British schematics Roberts, Hacker, Bush etc.Multi page manuals are Emailed as pdfs. Please Email if you have any queries,Thanks for looking, Mike.Some sources searched:-Gernsback 1922-34 Crosley 1929-42. Something went wrong. This item doesn't belong on this page. Cancel Thanks, we'll look into this. All Rights Reserved. Please refer to ourIf you are interested in consigning in future sales, please contact the specialist department. If you have queries about lots purchased in this sale, please contact customer services. Vervielfaltigung -Kopie- des Service Manuals fur Braun SK 55. Komplett in Originalgro?e als DIN A4. Der Versand der Vervielfaltigung erfolgt in gedruckter Form per Post. Alles fur einen perfekten Service Achtung: Sie kaufen nicht das Gerat. Gern erhalten Sie weitere Informationen. Sicherheitshinweis: Serviceunterlagen sind fur fachlich geschulte Techniker gedacht. Wir setzen voraus, dass das notige Wissen im Umgang mit Strom und den gultigen Sicherheitsbestimmungen vorhanden ist. Eine Verantwortung konnen wir nicht ubernehmen. Super high amount of views. 5 sold, 4 available. More Super high amount of views. 5 sold, 4 available. You are the light of the world. A newly developed 500 kW short-wave transmitter is the latest addition to BBC's family of modern short-wave and medium-wave transmitters with ratings from 100 to 300 kW. The most notable features of the new transmitter are: An exceptionally high modulator efficiency, achieved by using a solid-state switching amplifier Reduction of maintenance to a minimum thanks to computer-aided design of the transmitter, which now has fewer power components and parts subject to wear and tear. This new 500 kW short-wave transmitter keeps up the Brown Boveri tradition by setting new standards of efficiency, design and technology in this power class. RF STAGES Extensive computer calculations and trial runs on models provided some interesting technical solutions with respect to the best circuit layout for the entire short-wave range and also with regard to determining the optimum operating point. Preliminary Stages The preliminary stages up to the driver tube are fully transistorized and function as a broadband amplifier. The oscillator controls a programmable regulating stage, which ensures that the r.f. final-stage tube is driven properly at each operating frequency. The driver stage is equipped with a modern, condensed-vapour cooled BBC triode of type CTL 12-1, which has a high amplification factor. This amplifier tube operates in grounded-grid circuit. The broadband matching network is initially adjusted for each broadcasting band. Fine adjustment of the driver stage grid-circuit components is unnecessary due to the circuit layout chosen. Final Stage The r.f. final stage has a newly developed high-power tetrode of type CQK 650-1 from Brown Boveri. The tetrode is operated without grid current and delivers the rated power. A Pi-circuit, which is tuned to the set transmission frequency, matches the driver anode to the control grid of the r.f. final-stage tube. The output capacitance of the Pi-circuit is represented by the input capacitance of the r.f. final-stage tube, so that resonance sources on the grid side are eliminated. Power is coupled out over a cylindrical capacitor arranged around the anode of the r.f. final-stage tube. The result is an extremely compact design with low inductances in the leads and a homogeneous distribution of the current in the tube. The tube is easily accessible and simple to replace. The output circuit consists of three Pi-elements, which transform the 50 ohms terminating impedance to the desired anode impedance. In the standard version, the transmitter can be tuned continuously in the broadcasting bands from 5.9 MHz to 26.1 MHz. By changing the capacitances, the frequency range can be extended down to 3.9 MHz. The series inductances are designed as tunable loops. By making the inductances of the loops low, the frequencies of any unwanted resonances lie far above the operating frequency. All stray inductances of the incoming leads act as components of the loop and therefore do not constitute additional sources of interference resonances. The first shunt capacitor lies parallel to the r.f. final-stage tube and is disconnected at the higher transmitter frequencies. Compensation of the voltage standing wave ratio (VSWR) is achieved by adjusting the capacitor and the loop at the output. Possible antenna mismatch is therefore compensated for by the Pi-element closest to the output. Consequently, the currents and voltages in the rest of the anode network are the same as those during rated operation. Water is used to cool the loops and variable vacuum capacitors. Outstanding features of the PSM switching amplifier are: Dynamic carrier control (DCC) is possible with both modulators. The object of DCC is dynamic reduction of the carrier power as a function of the modulation peaks, and therefore also reduction of the input power. Push-Pull Class B Modulator The a.f. final stage is equipped with two power tetrodes of type CQK 200-3. These two amplifier tubes operate without grid current, so that a transistorized voltage amplifier suffices as the driver stage. The quiescent currents of the tetrodes can be set to low values since special correcting networks improve the linearity. The efficiency achieved in program service is therefore substantially higher than with conventional modulators. The anode voltage is led to the two modulator tubes via the mid-point of the modulation transformer's primary winding. The r.f. final-stage tubes receive the anode voltage from the modulation choke. A varistor connected in parallel with the secondary winding of the modulation transformer, protects the r.f. final-stage tube against overvoltage. PSM Amplifier The PSM amplifier delivers output voltages between 0 and 28 kV, corresponding to the program signals, and has an output rating which varies between 0 and 2800 kW. The mean d.c. component and the a.c. modulation component can be set separately. The amplifier can therefore be used with a reduced power output (e.g. for local supply). The PSM amplifier consists of approximately 40 switching stages, the outputs of which are connected in series. The number of stages to be connected depends upon the instantaneous value of the voltage to be amplified. Half of the switching stages deliver the carrier value, an appropriate number being switched on and off for higher or lower voltages, respectively. The 40 switching stages are fed by 40 d.c. power supplies from the mains, via a three-phase isolating transformer with one primary and 40 separate secondary windings. The secondary voltages are rectified and smoothed in an intermediate d.c. circuit. There is therefore a separate d.c. voltage source for each switching stage. Switch-on or switch-off of each individual stage is controlled via an optical-fibre cable. When the semiconductor valve is 'turned on', the corresponding voltage source is connected in series with the sources below it; when the valve is 'turned off', a bypass is created for the current. High-speed thyristors act as switching valves in this system. TRANSMITTER CONTROL SYSTEM The hinged frame contains the control equipment and monitoring instruments, and, from top to bottom, the r.f. frequency oscillator, reflectometer, measuring equipment, motor control system, frequency selector, operating unit with display lamps, logic, power supply and bridge memory. The key- switch in the operating unit can be turned to select manual, automatic or remote control of the switching sequences. The relevant switching status is monitored; i.e. switching commands are only carried out when all conditions have been met. The switching status and possible faults are displayed. In the position 'Automatic', the transmitter can be controlled with only three buttons: 'On', 'Standby' and 'Off'. The same three commands can be transmitted when the key is in the position 'Remote', for example from a central, computerized station control system or a control desk. When the key is in the position 'Manual', all of the variable capacitors and loops required for a frequency change can be set via the motor control unit by pressing the relevant buttons. The actual position is shown on a digital display. The automatic tuning system is activated by turning the key to 'Automatic'. Automatic tuning takes place in two steps, beginning with the operator pressing a button to transfer the desired transmission frequency from one of the 100 freely programmable memories in the frequency selector subassembly to the automatic transmitter tuning system. The r.f. oscillator immediately changes to the new transmitter frequency. Using the bridge memories, all tunable elements are then set to the selected broadcasting band. During the slow run-up of the anode voltage, phase and load discriminators monitor the fine tuning. COOLING All of the tubes used, such as the CTK 12-1, CQK 650-1 and, in the case of the push-pull class B modulator, the two CQK 200-3 tubes, are cooled by condensed vapour. Loops, their tuning contacts and variable vacuum-type capacitors are cooled by the same cooling water. A high-pressure fan is incorporated in the r.f. stage cubicle and in the push-pull class B modulator to cool the terminal heads of the tubes. Additional cooling is also provided by air at low pressure passing through the transmitter cabinets. SAFETY EQUIPMENT The safety system for the 500 kW short-wave transmitter complies in full with the recommendations set down in IEC 215-1. The system offers multiple protection. A key-interlock system combined with an earthing switch makes it impossible for doors leading to live equipment to be opened. Each door is also provided with a special contact which is integrated in the interlock circuit. An earthing hook situated behind each door offers additional security. POWER SUPPLY The transmitter can be supplied with power from a medium-voltage network rated 3 to 24 kV.