Schule, Abteilung: HTL Leonding, Elektronik und Technische Informatik Jahrgang: 4. Jahrgang Lehrer/in: Dipl.Ing. Peter Auer Schuljahr: 2011/2012 Gegenstand: Hochfrequenztechnik Thema: Wireless Microphone Unit Activity type/s Classroom format Time Procedure Resources Content-related learning outcome Language-related learning outcome Source/s 1. Reading for gist (“skimming”) and creating an English-German glossary 2. Reading for detail (“scanning”) and writing answers 3. Doing a role play 1. Individual work 2. Individual and pair work 3. Individual and pair work 50 minutes 1. Students read the handout and create their own glossaries by matching the English and German words given and by adding three words of their own. 2. Students read the input texts (General Information, Operating Instructions) once more. Then they get in pairs and answer a set of questions by writing down one sentence for each question. 3. Students role-play a job-related troubleshooting situation. They simulate a phone call by sitting back to back so that they cannot see each other. Handout: Wireless Microphone Unit Students can name specific parts and components of a wireless microphone unit. Students know how to operate a wireless microphone unit. Students know what to do when certain technical problems occur. Students can read for gist and for detail. Students can answer input-related questions in writing. Students can deal with troubleshooting situations on the phone. Bogen UHF wireless microphone www.bogen.com (11.10.2012) DIPL.-ING. P. AUER HFT_ Hochfrequenztechnik _ 4. Jahrgang Student’s version Wireless Microphone Unit General Information The wireless microphone unit contains a handheld microphone and a receiver unit. The receiver needs to be connected to an audio amplifier. The microphone is battery powered, the receiver is powered by an AC mains adapter. Operation Instructions 1) Connect the receiver to the audio amplifier. Switch on the amplifier and the receiver by using the power switch. 2) Switch on the microphone, by setting the ON/OFF switch to position “ON“. Now the power indicator is on. If the level of the radio signal is sufficient, the display on the receiver shows the RECEPTION indication. The indication RF shows the radio signal quality. The more segments displayed, the better the reception. For obtaining optimum transmission quality maintain line-of-sight between the microphone and the receiver. Make sure the distance between the microphone and the receiver is less than 10 meters and also make sure the reception is not affected by objects in the transmission path. Also avoid close operation to computers or other RF-generating equipment (allow at least 50 cm of distance). 3) Switch on the audio amplifier connected to the receiver. 4) Speak into the microphone and match the output level of the receiver to the input of the audio amplifier by adjusting the LEVEL CONTROL. The volume of the audio signal received is shown on the receiver display by the volume indication AUDIO. The more segments displayed, the higher the volume level. In case the receiver is overloaded "OVERLOAD" lights up. 5) The input amplification of the microphone is adjustable with the gain control. Reduce gain if the volume of the microphone signal is too high and thus distorted (indication "OVERLOAD"). Increase gain if the volume is too low and results in a poor signal to noise ratio. 6) To mute the microphone during operation, set the mute switch to the position "MUTE". Then no sound will be transmitted. 7) After operation switch off the receiver and the microphone. DIPL.-ING. P. AUER HFT_ Hochfrequenztechnik _ 4. Jahrgang Troubleshooting No power: Check the connection cable of the AC adapter and any extension-cables. No sound and receiver RF indicator does not light: Make sure microphone and receiver are switched on. Check the microphone battery LED to ensure that the battery is ok. Replace the battery if necessary. Make sure that the receiver is in line of sight of the microphone. If necessary, reduce the distance between microphone and receiver. No receiver sound and receiver RF indicator lights: Check if the audio amplifier is on. Check for proper connection between receiver and amplifier. Increase the receiver audio output level. Talk into the microphone and observe the receiver's RF indicator. If it lights up, the problem is somewhere else in the sound system. Received signal is noisy or contains strange sounds with microphone on: Check the transmitter's battery LED to ensure that battery ok. Remove local sources of RF which may cause interference. The signal may be too weak. If possible, move the receiver closer to the transmitter. Noise from receiver with microphone off: Remove local sources of RF interference, such as lighting equipment. Reposition the receiver. Momentary loss of sound as the microphone is moved around the area: Reposition receiver and perform another test and observe the RF indicator. If audio drop-outs persist, mark these dead spots in the area and avoid them during the performance. DIPL.-ING. P. AUER HFT_ Hochfrequenztechnik _ 4. Jahrgang Task 1: Increasing your word-power Read all the texts quickly and create your own glossary of important words and terms by 1) matching the English and German words and terms in the table below. 2) adding three more words and terms of your own choice. English AC mains adapter RF line-of sight to affect transmission path to match distorted signal to noise ratio to mute extension cable dead spot German Sichtverbindung beeinflussen Verlängerungskabel stumm schalten Signal-Rauschabstand Steckernetzteil angleichen tote (Empfangs-)Zone verzerrt Übertragungsweg HF (Hochfrequenz) DIPL.-ING. P. AUER HFT_ Hochfrequenztechnik _ 4. Jahrgang Task 2: Checking your understanding Read the first and the second part of the handout General Information and Operating Instructions more carefully. Get in pairs and answer the following questions. Answer each question with one sentence. Write them down. 1) Is it possible to use the Wireless Microphone Unit from one room to another separated by a brick wall? Explain. 2) How do you know that the RF-level at the receiver is too low? 3) Is there a way to check on the audio signal level? Explain. 4) Can the receiver be powered by battery? Explain. 5) You are speaking into the microphone and you start coughing. What can you do to avoid the annoying sound effect? Task 3: Simulating a troubleshooting situation Read the troubleshooting text again, get together in pairs and role-play the following situation then: A customer who has purchased a Wireless Microphone Unit calls your company because his/her unit is not working properly. AC supply and microphone batteries are fine, audio amplifier is fine but there is no sound from the microphone. One of you is supposed to be the customer, the other one the troubleshooter. Simulate the conversation on the phone (by sitting back to back). The troubleshooter asks specific questions and comes up with an answer to make the customer’s equipment work properly again. DIPL.-ING. P. AUER HFT_ Hochfrequenztechnik _ 4. Jahrgang Teacher’s version Key for tasks 1 and 2 Task 1: Increasing your word-power English AC mains adapter RF line-of sight to affect transmission path to match distorted signal to noise ratio to mute extension cable dead spot German Steckernetzteil HF (Hochfrequenz) Sichtverbindung beeinflussen Übertragungsweg angleichen verzerrt Signal-Rauschabstand stumm schalten Verlängerungskabel tote (Empfangs-)Zone Task 2: Checking your understanding 1) It is possible, although the RF-level at the receiver might be low due to the attenuation of the brick wall. 2) The display RECEPTION at the front panel of the receiver is off. 3) The audio signal level is controlled by the volume indication AUDIO and the more segments displayed, the higher the volume level. 4) No, because of higher power consumption the receiver must be powered by an AC mains adapter. 5) There is a mute switch and when you press it, the coughing sounds will be suppressed.