T187 VHF HAND-HELD TRANSMITTER OPERATING INSTRUCTIONS and trouble-shooting guide LECTROSONICS, INC.
INTRODUCTION Thank you for selecting the Lectrosonics T187 hand-held wireless transmitter. The T187 combines over 80 years of engineering experience with the very latest compo nents in a design that addresses the most demanding professional applications. The design of the T187 was the direct result of numerous conversations with users, staging and touring companies and dealers across the US.
VHF Hand-held Transmitter GENERAL TECHNICAL DESCRIPTION The T187 transmitter is comprised of a number of functional sub-systems as shown in the block diagram below. It is offered with a variety of popular dynamic and electret microphone capsules from Shure, Electro-Voice and others for various applications. The limiter is a low distortion shunt FET compressor operating before the mic preamp.
CONTROLS AND FUNCTIONS EXTERNAL “P” SWITCH -- POWER ON/OFF A slide switch which turns battery power on and off. The LED next to the switch lights up when the “P” switch is turned on. This LED also serves as a battery condition indicator. The LED will glow brightly when the battery is good and will dim as the battery condition deteriorates. The LED is at full brightness with a new battery. After 12 to 15 hours of operation the battery voltage will be about 7 Volts and the LED will be completely dark.
VHF Hand-held Transmitter INTERNAL CONTROLS - SHURE SM87 VERSION -10 dB This switch enables an extra 10dB of audio attenuation for those rare times when the Audio Level control is already at minimum and the mic is still overload ing. The 10dB attenuator should only be used as a last resort. Do not leave it enabled when it is not needed. To gain access to the switch, turn the windscreen counter-clockwise and remove it. Slide the switch handle toward the -10dB label to activate the attenuator.
BASS FILTER In addition to the tone controls, the T187 also has a built in bass filter. This filter is fixed and cannot be adjusted or defeated. Low frequency noise is much more of a problem with wireless microphones than with conventional micro phones. With a regular mic, low frequency wind noise, breath thumps or handling rumble can be filtered out at the control board before the noise causes problems with the following electronics or speaker systems.
VHF Hand-held Transmitter BATTERY INSTALLATION The T187 transmitter is powered by a standard alkaline 9 Volt battery. It is important that you use ONLY an ALKA LINE battery for reliable operation. Alkaline batteries will provide about 15 hours of operation and the battery status lamp will function normally. Standard zinc-carbon batteries marked “heavy duty” or “long-lasting” are not adequate. They will provide only about 4 hours of operation.
OPERATING INSTRUCTIONS 1) Install a fresh battery according to the instructions on page 7. 2) Move the internal bypass slide switches to the left-hand position so that the battery status LED and the bottom panel switches will operate. 3) Move the “A” (audio) switch to “OFF” and the “P” (power) switch to ON (in that order). Observe that the battery status LED is brightly lit. If the LED is dim, replace the battery. 4) Hold the microphone in the same position that will be used in actual operation.
VHF Hand-held Transmitter 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 TRANSMITTER BATTERY LED OFF 1) External LED is turned off. Check internal slide switch. 2) Battery is inserted backwards. 3) Battery is dead. NO TRANSMITTER MOD LEVEL LEDs 1) Gain control turned all the way down. 2) Battery is in backwards. Check power LED.
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 intercon necting 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.
VHF Hand-held Transmitter SPECIFICATIONS AND FEATURES Operating frequencies: 150 to 216 MHz RF Power output: 50mW Deviation: ± 15kHz Spurious emissions: 55dB below carrier Equivalent input noise: -126dBV Input compressor: Soft compressor, 20 dB range allows 3 Volt max.
LIMITEDONE ONE YEAR LIMITED YEARWARRANTY 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, Lectrosonics, Inc.
