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 FM875 combination wireless receiver/amplifier/speaker with a rechargeable battery pack, an M175 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 CHARGE UNTIL GREEN LED GOES OUT OR LONGER CHARGE WIRELESS MIC VOLUME 4 –20 RF AUX VOLUME MIC OR AUX 6 4 6 AUX LINE IN OUT MIC LEVEL OUTPUT OMNI–BUS 3 LIMIT 8 2 8 2 MODULATION ADJUST MIC GAIN ON TRANSMITTER UNTIL LIMIT LED FLASHES ON VOICE PEAKS 2 1 IN/OUT IN 0 0 10 10 LO-Z BAL POWER LECTROSONICS (Items are listed in right to left order as shown on the panel above.) POWER: A toggle switch which turns the power off and on.
MIC LEVEL OUTPUT: LINE OUT: A 3-pin XLR audio connector which provides a balanced, low impedance (200 Ohm), 10 millivolt, microphone level output suitable for house sound systems, microphone mixers and other units requiring a microphone level input. Pin 1 is Ground or Shield, pin 2 is Audio High, and pin 3 is Audio Low. If using an unbalanced load, pin 1 is Ground, pin 2 is Audio and pin 3 is not used. The output level at this jack varies with the setting of the WIRELESS MIC VOLUME and AUX VOLUME knobs.
TRANSMITTERS Standard FM-AV4 systems include an M175 belt-pack transmitter which is designed to be used with a lavalier or headset microphone. If you have one of the other optional Lectrosonics transmitters, consult the supplied manual for that transmitter for the description and operating instructions. The MIC JACK is a locking micro jack that supplies "phantom power" for electret microphones such as the Lectrosonics M130, M140 and the HM142V and HM152V headset models.
TRANSMITTERS cont’d The battery you use in the M175 Series transmitter should be a 9 Volt alkaline, available almost everywhere. An alkaline battery will provide up to 15 hours of operation. Carbon zinc batteries, even if marked "heavy duty" will only provide about 4 hours of operation. Make sure your batteries are marked "alkaline." Short battery life is almost always caused by weak batteries or batteries of the wrong type.
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 FM875 fully before you use the system. 3) The internal antenna is built into the cabinet of the amplifier/speaker unit. Position the FM875 so that it is not 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 FM875. 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 INSTRUCTIONS This section covers the initial adjustments to the FM875 and the companion transmitter that must be made before the system is placed into operation: 1) 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. 2) Turn both volume controls on the FM875 control panel to minimum (fully counter-clockwise). 3) Set the power switch to ON.
OPERATING INSTRUCTIONS cont’d USING HARD-WIRED MICROPHONES Any 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 MIC OR AUX IN. 3) Flip the switch on the microphone and bring the AUX VOLUME up slowly to the desired volume. If the speaker squeals, the microphone is too close to the speaker. A longer microphone cord will reduce this noise.
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 FM875 POWER LAMP NOT ON OR DIM 1) Power 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. FM875 RF LAMP OFF 1) Transmitter not turned on.
ACCESSORIES AND REPLACEMENT PARTS ITEM DESCRIPTION USE CH-40 Battery Charger Replacement HM142V Single headband Headset Microphone With locking micro plug HM152V Double headband Headset Microphone With locking micro plug M121S Dynamic Microphone For hand-held use plugged into the AUX MIC INPUT jack of the FM875 (cord not supplied). MC-16C Microphone Cord 16 ft.
SPECIFICATIONS OVERALL FM-AV4 SYSTEM Operating frequency: Wireless operating range: FM deviation: Distortion: 169 to 186 MHz Up to 750 feet ±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.
