FM-AV4 PORTABLE WIRELESS SOUND SYSTEM OPERATING INSTRUCTIONS and trouble-shooting guide LECTROSONICS, INC.
INTRODUCTION Thank you for selecting the FM-AV4 Portable Wireless Sound System. This system represents over 80 years of combined experience in the design of RF transmitters, receivers and Public Address systems. The FM-AV4 sets new standards for operational convenience, flexibility and mechanical ruggedness. The builtin wireless receiver, the rechargeable power supply and the high quality of the audio output set this system apart from any other portable PA system on the market.
GENERAL TECHNICAL DESCRIPTION The FM-AV4 Portable Wireless Sound System consists of an FM870 combination wireless receiver/amplifier/speaker with a rechargeable battery pack, an M170 belt-pack transmitter and a microphone. Optional microphones, transmitters and accessories are available. These items will be discussed elsewhere in this manual. The FM-AV4 features a VHF high band wireless microphone system with excellent operating range, freedom from "dropouts" and interference from other radio transmissions.
CONTROLS AND FUNCTIONS POWER/FUNCTION: A rotary switch which turns the power off and on and selects the operating mode. OPERATE: Set in this position for normal use when the built-in speaker is to be used. SPEAKER OFF: Set in this position for use with the FM870 plugged into the house sound system. The wireless microphone will operate, but the sound from the built-in speaker will be muted. CHARGE: Set in this position to recharge the built-in battery pack.
CONTROLS AND FUNCTIONS cont’d WIRELESS MIC VOLUME: AUX MIC/HI LEVEL VOLUME: This control adjusts the volume of the built-in wireless microphone system. This knob does not affect the MODULATION LEDs located near it. This control adjusts the volume of the AUX MIC INPUT and the HI LEVEL IN inputs. AUX MIC INPUT: This jack is a standard 1/4" phone jack and will accept a high impedance dynamic microphone. It is recommended that you use the LECTROSONICS RM-121S microphone with an MC-16C or MM-16 cord.
M170 SERIES TRANSMITTERS Standard FM-AV4 systems include an M170 belt-pack transmitter which is designed to be used with a lavalier or headset microphone. The optional M170-XLR transmitter (see page 6) is similar to the M170 but is equipped with two microphone connectors - a locking micro jack for lavalier or headset microphones and an XLR connector for use with standard low impedance hand held microphones.
M170 SERIES TRANSMITTERS cont’d The BATTERY used in the transmitter should be a 9 Volt alkaline battery which will provide up to 15 hours or more of operation. These are available almost anywhere. Carbon zinc batteries, even if marked "heavy duty" or "super heavy duty", will only operate up to 4 hours. Make sure "alkaline" is marked on the battery. The BATTERY INDICATOR will light when the transmitter is turned on and will stay lit as long as the battery is good.
SYSTEM SETUP This section includes some basic steps that will ensure trouble-free operation of your FM-AV4 system: 1) Make sure the transmitter battery is good, or better yet, new. 2) Charge up the battery pack in the FM870 fully before you use the system. 3) Extend the antenna fully. Position the FM870 so that the antenna is not touching or within 3 or 4 feet of large metal surfaces such as air conditioning ducts.
SYSTEM SETUP cont’d 4) If you have more than one transmitter on the same frequency, turn on only one transmitter at a time. You cannot use the two transmitters at the same time with a single FM870. You will need to "alternate" back and forth between the transmitters. Failure to do so will result in an obnoxious whining sound from the system, and the audio will probably not be understandable. 5) Use the minimum volume that will enable everyone to hear. It doesn’t have to be loud to be heard.
OPERATING TIPS WHAT ARE THE CAUSES OF FEEDBACK? Feedback (squealing) occurs when the sound from the speaker re-enters the microphone, comes back out of the speaker again and re-enters the microphone, and so on. At a given distance between the microphone and speaker, the sound can only be turned up so loud before feedback occurs. Moving the mic further away from the speaker (or the speaker away from the mic) will allow a louder setting of the sound system. MAXIMIZING GAIN 1.
OPERATING INSTRUCTIONS This section covers the initial adjustments to the FM870 and the companion transmitter that must be made before the system is placed into operation: 1) Make sure the antenna is extended fully. 2) Connect the audio output cable as required. If you are connecting into a "house" sound system or external audio or recording equipment, make those connections before turning on the power. 3) Turn both volume controls on the FM870 control panel to minimum (fully counter-clockwise).
OPERATING INSTRUCTIONS cont’d USING HARD-WIRED MICROPHONES Any low inpedence, unbalanced, dynamic microphone can be plugged into the AUX MIC INPUT. 1) Make sure the volume knobs are set at "0." 2) Plug an auxiliary cord (a MM-16 or MC-16C will work) into your microphone and into the AUX MIC INPUT. 3) Flip the switch on the microphone and bring the AUX MIC VOLUME up slowly to the desired volume. If the speaker squeals, the microphone is too close to the speaker.
MICROPHONE CHOICES M140 - This is the microphone supplied with the standard FM-AV4 system. It is a cardioid (directional) microphone for lavalier ("lapel") use. Due to the directional pickup pattern, this model will generally provide more gain (loudness) before feedback than the M130 omni-directional model. The M140 has a "brighter" sound than the M130 (the treble is boosted). This brighter sound normally improves the clarity that is sometimes lost with lavalier type microphones.
TROUBLESHOOTING Before going through the following chart, be sure that you have a good battery in the transmitter. It is important that you follow these steps in the sequence listed. SYMPTOM POSSIBLE CAUSE FM870 POWER LAMP NOT ON OR DIM 1) Power/function switch in OFF position 2) Batteries completely discharged 3) Battery connections loose TRANSMITTER BATTERY LED OFF 1) Transmitter power switch off. 2) Battery is inserted backwards. 3) Battery is dead.
ACCESSORIES AND REPLACEMENT PARTS ITEM DESCRIPTION USE CH-40 Battery Charger Replacement HM142V Single headband Headset Microphone With locking micro plug for M170 series transmitters. HM152V Double headband Headset Microphone With locking micro plug for M170 series transmitters. M121S Dynamic Microphone For hand-held use plugged into the AUX MIC INPUT jack of the FM870 (cord not supplied). MC-16C Microphone Cord 16 ft.
SPECIFICATIONS OVERALL FM-AV4 SYSTEM Operating frequency: Wireless operating range: FM deviation: Distortion: 150 to 216 MHz Up to 750 feet + or - 15 KHz less than 1% AMPLIFIER Audio power output: Amplifier freq.
SERVICE AND REPAIR If your system malfunctions, you should attempt to correct or isolate the trouble before concluding that the equipment needs repair. Make sure you have followed the setup procedure and operating instructions. Check out the inter-connecting cords and then go through the TROUBLE SHOOTING section in the manual We strongly recommend that you do not try to repair the equipment yourself and do not have the local repair shop attempt anything other than the simplest repair.
LIMITED ONE YEAR WARRANTY The equipment is warranted for one year from date of purchase against defects in materials or workmanship provided it was purchased from an authorized dealer. This warranty does not cover equipment which has been abused or damaged by careless handling or shipping. This warranty does not apply to used or demonstrator equipment. Should any defect develop, we will, at our option, repair or replace any defective parts without charge for either parts or labor.
