UM195 BELT-PACK TRANSMITTER OPERATING INSTRUCTIONS and trouble-shooting guide LECTROSONICS, INC.
INTRODUCTION Thank you for selecting the Lectrosonics UM195 belt-pack transmitter. The UM195 combines over 80 years of engineering experience with the very latest components, in a design that addresses the most demanding professional applications. The design of the UM195 was the direct result of numerous conversations with users, staging and touring companies and dealers across the US.
GENERAL TECHNICAL DESCRIPTION The UM195 transmitters are comprised of a number of functional sub-systems as shown in the block diagram below. The 195 system uses 75kHz wide deviation for an extremely high signal to noise ratio. The transmitter circuits are all regulated to allow full output power from the beginning (9 Volts) to the end (7 Volts) of battery life. The oscillator crystal is shock mounted to provide ruggedness. The input amplifier uses a Motorola 33078 op amp for ultra low noise operation.
The signal to noise ratio of the 195 system is high enough to preclude the need for conventional pre-emphasis (HF boost) in the transmitter and de-emphasis (HF roll off) in the receiver. Pre-emphasis and de-emphasis in an FM radio system usually provides about a 10dB improvement in the signal to noise ratio of the system, but the high frequency boost in the transmitter must be removed in a purely complementary manner or else the frequency response of the original audio signal will be altered.
CONTROLS AND FUNCTIONS 150Hz UM 195 LF ROLL-OFF ADJ 30Hz LECTROSONICS ON MUTE OFF LEVEL LIMIT MIC LEVEL Figure 2 - UM195 Controls and Functions INPUT JACK The input on the UM195 accommodates virtually every lavalier, hand-held or shotgun microphone available. Use a Switchcraft TA5F connector on the cord. See the separate sheet titled "UM195 Input Jack Configuration" regarding the correct connections for various microphones, and other sources. ON/MUTE/OFF SWITCH Turns the battery power on and off.
CONTROLS AND FUNCTIONS (cont’d) Since the internal circuits are all tightly regulated and the RF output stage has a separate discrete regulator, the transmitter will continue to operate to a battery voltage of 6.5 Volts. From 6.5 Volts to 6 Volts, the transmitter will still operate, but with degraded performance.
BATTERY INSTALLATION The transmitter is powered by a standard alkaline 9 Volt battery. It is important that you use ONLY an ALKALINE battery for longest life. Standard zinc-carbon batteries marked "heavy-duty" or "long-lasting" are not adequate. Ni-cad rechargeable batteries will only provide 2 hours of operation, or less, and will run down quite abruptly. Alkaline batteries provide over 7 hours of operation on UHF versions and over 10 hours of operation on VHF versions.
OPERATING INSTRUCTIONS 1) Install a fresh battery according to the instructions on the previous page. 2) Insert the microphone plug into the input jack, aligning the pins; be sure that the connector locks in. 3) Attach the antenna to the jack on the bottom of the transmitter. 4) Turn the power switch to the "MUTE" or "ON" position on the transmitter. 5) Position the microphone in the location you will use in actual operation.
UM195 INPUT JACK WIRING The wiring diagrams shown on the separate sheet represent the basic wiring necessary for the most common types of microphones and other audio inputs. Some microphones may require extra jumpers or a slight variation on the diagrams shown. It’s virtually impossible to keep completely up to date on changes that other manufacturers make to their products. It is possible that you may encounter a microphone that differs from these instructions.
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) Battery is inserted backwards. 2) Battery is dead.
SPECIFICATIONS AND FEATURES Operating frequencies: UM195: 470 to 608 MHz RF Power output: UM195: 100 mW (nominal) Pilot tone: 32.768 kHz (± 2Hz); 5kHz deviation Frequency stability: ± .002% Deviation: ± 75 kHz (max) Spurious radiation: 50 dB below carrier Equivalent input noise: -126 dBV Input level: Nominal 2 mV to 300 mV, before limiting. Greater than 50 Volts maximum, with limiting.
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 TROUBLESHOOTING 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.
