INSTRUCTION MANUAL R172 DUAL-RECEIVER LECTROSONICS, INC. 581 Laser Road Rio Rancho, NM 87124 USA Tel (800) 821-1121 or (505) 892-4501 fax (505) 892-6243 e-mail: sales@lectrosonics.com web: www.lectrosonics.
INTRODUCTION The R172 receiver is a fixed frequency design two channel wireless microphone receiver. Designed to offer two simultaneous channels of wireless microphones, the R172 will can operate both channels from one antenna or two for passive diversity operation. The dual antenna configuration reduces the probability of dropouts resulting from multipath interference.
RECEIVER FRONT PANEL Front panel controls on the R172 are identical for each channel and operate independently from each other. MODULATION -- Indicates the modulation (audio level) of the incoming signal. The green LED indicates an adequate modulation level. The red LED indicates maximum or "peak" modulation. OUTPUT LEVEL -- An output attenuator is used to reduce the audio output level of the receiver. Reduces the audio output levels of the XLR jacks in the rear by rotating the knob counter-clockwise.
RECEIVER REAR PANEL ANTENNA terminals -- Standard BNC 50 ohm connectors for connecting the antennas. The R172 is normally shipped with a telescoping whip antenna and a coaxial antenna. Rack mounted units are shipped with two coaxial antennas. ANTENNA MODE - The unit may be operated as either a single antenna or a dual antenna system. If two antennas are used set the switch to DUAL. If operating with only one antenna, set the switch to SNGL.
Figure 2 R172 Rear Panel 4
OPERATING INSTRUCTIONS SET UP AND OPERATION SEQUENCE 1) CONNECT POWER CORD -- Plug the connector of the CH-12 adapter included with the receiver into the jack labeled "12 VDC INPUT." Insert the plug fully into the jack. 2) ATTACH THE ANTENNAS - Two antennas are provided with the receiver. If the system is not rack mounted, the unit will have a telescoping whip antenna and a coaxial dipole antenna (this antenna looks like a piece of cable with a small loop in one end and a BNC connector on the other).
If the system will be installed with dual antennas - Attach both antennas to the dual BNC connectors on the back of the receiver. Set the ANTENNA MODE switch to the DUAL position. If a telescoping whip is used, fully extend the whip. DO NOT USE TWO TELESCOPING WHIPS ATTACHED SIDE BY SIDE AT THE RECEIVER. There is little to no benefit of placing the antennas side by side. Place the coaxial antennas in the same manner as described above.
3) CONNECT THE AUDIO CABLE/S If the receiver will be connected directly to an amplifier and there is only one audio input available, set the SEPARATE/MIXED switch to the mixed position and connect the cable to either the "A" or "B" output jack. You may also used the MIXED position to connect the receiver to a tape deck and an amplifier for simultaneous recording. See the illustration below.
ANTENNA USE AND PLACEMENT Extend the antennas fully. Position the antennas so that they are not touching each other or within 3 or 4 feet of large metal surfaces. It is also good practice to position the receiver so that there is a direct "line of sight" between the transmitter and the receiver antenna. In the dual antenna mode, place the antennas at least 6 ft apart.
MULTI-CHANNEL AUDIO MIXING The R172 receiver offers a unique feature that eliminates the necessity of using an external audio mixer in multi-channel applications. When using two R172 receivers together, the LINE LEVEL and AUX INPUTS jacks provide "unity gain" mixing of the audio signals. This means that the audio output of the receivers may be mixed together through these connectors without affecting the volume levels.
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 1) External LED is turned off. Check internal slide switch. 2) Battery is inserted backwards. 3) Battery is dead. ---------------------------------------------------------------1) Gain control turned all the way down. NO TRANSMITTER MOD LEVEL LEDs 2) Battery is in backwards. Check power LED.
SPECIFICATIONS Operating frequencies: 150 to 216 MHz crystal controlled Sensitivity: 1.0uV for 20dB SINAD 2.0uV for 50dB S/N ratio Signal/noise ratio: 96 dB A-weighted Squelch quieting: greater than 96 dB AM rejection: better than -40 dB (10uV to 0.1 volts) Modulation acceptance: +/- 15KHz Image/spurious rejection: greater than 100 dB Audio outputs: * XLR: 200 ohm balanced; 100mV max. * RCA: 1K ohm unbalanced; 1 volt max.
FACTORY REPAIR SERVICE ALWAYS CONTACT THE FACTORY BEFORE SHIPPING ANYTHING BACK FOR SERVICE. DO NOT try to repair this transmitter yourself. DO NOT try to adjust any controls inside the unit. Alignment of the receivers requires a spectrum analyzer, an RF voltmeter, and a wide bandwidth oscilloscope. The various controls and trimmers do not drift with age or vibration. Once they are set at the factory they never require readjustment.
