UH400 FREQUENCY-AGILE PLUG-ON UHF TRANSMITTER OPERATING INSTRUCTIONS and trouble-shooting guide LECTROSONICS, INC. Rio Rancho, NM www.lectrosonics.
UH400 INTRODUCTION Thank you for selecting the Lectrosonics UH400 frequency agile, plug-on transmitter. The UH400 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 UH400 was the direct result of numerous conversations with users, staging and touring companies and dealers across the US.
Frequency Agile Plug-on UHF Transmitter GENERAL TECHNICAL DESCRIPTION GENERAL The 400 system uses 75kHz wide deviation for an extremely high signal to noise ratio. The switching power supplies provide con stant voltages to the transmitter circuits from the beginning (9.3 Volts) to the end (5.5 Volts) of battery life. The input amplifier uses an ultra low noise op amp for quiet operation.
UH400 extends this concept even further by insuring that all transmitters in a system have different pilot tone frequencies so that even spurious RF from the wrong transmitters can’t open the receiver squelch. NO PRE-EMPHASIS/DE-EMPHASIS The signal to noise ratio of the 400 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.
Frequency Agile Plug-on UHF Transmitter indication immediately after being put in the unit, but will soon discharge to the point where the LED will go red or shut down, just like a flashlight with “dead” batteries. If the lamp fails to light, the battery should be replaced. lavaliere mic that was wired directly to an XLR for use with the earlier UH200's, we strongly recommend building our protection circuit into the XLR to prevent accidental destruction of the lavaliere.
UH400 INPUT LIMITER The 400 series transmitters employ a digitally-controlled analog audio limiter just before the analog-to-digital converter. The limiter has a range of more than 30dB for excellent overload protection. A dual release envelope makes the limiter acousti cally transparent while maintaining low distortion. It can be thought of as two limiters in series, connected as a fast attack and release limiter followed by a slow attack and release limiter.
Frequency Agile Plug-on UHF Transmitter OPERATING TIPS SELECTING THE OPERATING MODE The MIC LEVEL control knob should not be used to control the volume of your sound system or recorder levels. This gain adjustment matches the transmitter gain with the user’s voice level and microphone positioning. This unit is capable of working with Lectrosonics 100 series analog, 200 series analog, 400 series digital hybrid or some other analog wireless receivers (contact the factory for details).
UH400 BATTERY REPLACEMENT The UH400 transmitter is powered by a standard alkaline 9 Volt battery. It is important that you use ONLY ALKALINE OR LITHIUM batteries for longest life. Standard zinc-carbon batter ies marked “heavy duty” or “long-lasting” are not adequate. They will provide only about 5 minutes of operation. Similarly, ni-cad rechargeable batteries only give 1 hour of operation, and will also run down quite abruptly. Alkaline batteries provide about 4.
Frequency Agile Plug-on UHF Transmitter SYMPTOM POSSIBLE CAUSE RECEIVER RF LAMP OFF 1. Transmitter not turned on. 2. Transmitter battery is dead. 3. Receiver antenna missing or improperly positioned. 4. Transmitter and receiver not on same frequency. Check switches/ display on transmitter and receiver. 5. Operating range is too great. NO SOUND (OR LOW SOUND LEVEL), RECEIVER MOD LEVEL LEDs ARE ON 1. Receiver output level set too low. 2. Receiver output is disconnected; cable is defective or mis-wired.
UH400 SPECIFICATIONS AND FEATURES Operating frequencies: 537.600 to 607.900 MHz; 614.100 to 793.500 MHz Frequency selection: 256 frequencies in 100kHz steps RF Power output: 100 mW (nominal) Pilot tone: 25 to 32 kHz; 5kHz deviation (in 400 Series mode) Frequency stability: ± 0.002% Deviation: ± 75 kHz max. (in 400 Series mode) Spurious radiation: 60 dB below carrier Equivalent input noise: –118 dBV, A-weighted Input level: Nominal 2 mV to 300 mV, before limiting; Greater than 1.
Frequency Agile Plug-on UHF Transmitter 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.
LIMITED ONE ONE YEAR WARRANTY LIMITED 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, Lectrosonics, Inc.
