Project Solutions (2011/08/19)

Frequency Spectrum from DC to 30 GHz in 4 pages 3

Published:2011/8/19 4:36:00 Author:Amy

Paul Goossens 27 MHz The 27 MHz band, also known as CB {Citizens Band) or 11 meters, lies between 27.60 MHz and 27.99 MHz in the UK, and between 26.96 MHz and 27.41 MHz in the EU. In the UK a license is required (o use CB, although in many other European countries this is no longer the case. Lorry drivers and cabbies are one group of people who are well known for their use of CB to ...   (View)

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Frequency Spectrum from DC to 30 GHz in 4 pages 2

Published:2011/8/19 4:32:00 Author:Amy

Paul Goossens Professional communications Apart from radio and television broadcasting, there are many more applications where radio is used for the exchange of information. Just think of the communications in aviation, shipping, the police, etc. These particular groups also hove various parts of the sp...   (View)

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Frequency Spectrum from DC to 30 GHz in 4 pages 1

Published:2011/8/19 4:29:00 Author:Amy

Paul Goossens Life without wireless communications is almost unthinkable in the modern world. These days virtually everybody makes use of some type of transmitter or receiver: GSMs, broadcast radio and TV, WLAN, Bluetooth, and so on. And there is still a lot more happening in the radio spectrum. In this article we show what else can be found in ’the ether’. Over the years, organizat...   (View)

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Wireless Microphone: Audio in the ISM band 4

Published:2011/8/19 2:15:00 Author:Amy

Ton Giesberts Interface Thanks to these complex modules that include almost all the necessary elec­tronics, what remains is straightfor­ward. Figure 4 shows the two parts of the circuit. In the transmitter we can either connect a microphone or any other desired audio source with a max­imum output level of -15 dBV. In most cases, however, an electrets micro­phone will...   (View)

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Wireless Microphone: Audio in the ISM band 3

Published:2011/8/19 2:07:00 Author:Amy

Ton Giesberts The receiver The block diagram of the WA-RX-01 receiver module shown in Figure 3 is practically the mirror image of the transmitter, using similar components. RF band-pass filter (SAW...   (View)

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Wireless Microphone: Audio in the ISM band 2

Published:2011/8/19 2:01:00 Author:Amy

Ton Giesberts The transmitter Figure 2 shows the functional blocks of the WA-TX-01 transmitter. We will look at each in turn. Input buffer (BUF) This circuit is an input buf...   (View)

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Wireless Microphone: Audio in the ISM band 1

Published:2011/8/19 1:55:00 Author:Amy

Ton Giesberts The WA-TX-01 (transmitter) and WA-RX-01 (receiver) modules represent a novel concept in the wireless transmis­sion of audio signals. Thanks to low power consumption, the technology leads itself to a wide range of audio applications. The transmitter and the receiver include components such as SAW fi...   (View)

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OPINIONS ON VALVES （3）

Published:2011/8/19 1:52:00 Author:Phyllis

The valve sound: myth or reality? By Klaus Rohwer, PhD That famous valve sound, does it really exist? Yes, it does — but it doesn’t have to come from a valve! Here we have to make a distinction between devices for producing music and devices for reproducing music. The first category includes music amplifiers(View)

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OPINIONS ON VALVES （2）

Published:2011/8/19 1:42:00 Author:Phyllis

By Bernhard Vollmer The valve microphone: physics versus emotions The author has been actively involved in quality assurance at Schoeps, a German manufacturer of studio microphones, for nearly two decades. As a supplier to Schoeps, his company Elvo makes the model M222 valve microphone (www.m222.de). What would music be without emotion? Should our experience, ears and sensit...   (View)

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OPINIONS ON VALVES （1）

Published:2011/8/19 1:29:00 Author:Phyllis

Valves versus transistors We have two audio amplifier design articles in this issue: one with valves and the other with transistors. They are just as different as people’s opinions on the issue of valves versus transistors. Does it make sense to go back to the amplifier technology of our grandparents? Is...   (View)

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AUDIO-TWEAKS from demagnetizing to varnishing （2）

Published:2011/8/19 1:15:00 Author:Phyllis

By Harry Baggen The activities the American company CyroPlus are less strange, and they also have a technical explanation. What they do is to chill interconnecting cables and speaker cables, as well as individual valves and ICs or even entire circuit boards, down to absolute zero. The idea behind this is that it restores the original crystalline structure of the materials i...   (View)

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AUDIO-TWEAKS from demagnetizing to varnishing （1）

Published:2011/8/19 1:06:00 Author:Phyllis

By Harry Baggen For true audio enthusiasts, nothing’s too far out when it comes to improving the sound quality of their hi-fi or surround-sound systems. Naturally, you can spend a lot of money on cables and other accessories, but there are a lot of possibilities that go even further, such as equipment modification...   (View)

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Bidirectional S/PDIF Converter

Published:2011/8/19 0:49:00 Author:Phyllis

By Joseph Kranz Although S/PDIF is the standard when it comes to conveying digital audio signals in consumer electronics equipment, difficulties may be encountered if you try to connect up two apparatus having digital connections. Cheap equipment usually has only one connection (coaxial or optical), while more up-market products will generally offer both variants. When interconnecting CD an...   (View)

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