R170
RECEIVER
OPERATING INSTRUCTIONS
and trouble-shooting guide
LECTROSONICS, INC.
Rio Rancho, NM
INTRODUCTION
Thank you for selecting the Lectrosonics R170 receiver. This system provides reliable performance
and flexibility for a wide range of uses. The high selectivity provides protection from interference while
the high sensitivity increases the operating range and resistance to dropouts. A unique automatic
squelching system eliminates excess noise output from the receiver when the transmitter is turned off.
The R170 receiver was packaged for use with sound reinforcement and recording systems utilizing
balanced audio lines. Outputs for high or low impedance, balanced or un-balanced audio signals via
1/4", XLR and RCA jacks are provided. The versatile audio output section makes the R170 ideal for
applications where multiple audio feeds are required, such as providing PA system feed, "overflow
room" feed and tape recording signals simultaneously. This can be accomplished directly from the rear
panel connectors without external equipment.
In addition to the output jacks, a unique audio input on the rear panel allows "stacking" the receivers
together (up to three channels) in multi-channel applications without having to use a separate audio
mixer. This audio input jack also permits connection of a tape player to the receiver to mix tape
playback with the receiver output.
Matching FREEDOMIKE transmitters are available in several configurations for a wide variety of
applications in pro sound, pro video, theater/stage, and audio visual applications.
TABLE OF CONTENTS
INTRODUCTION .......................................... 1
GENERAL DESCRIPTION ................................... 2
RECEIVER FRONT PANEL ................................... 3
RECEIVER REAR PANEL .................................... 4
USE AND PLACEMENT ..................................... 5
OPERATING INSTRUCTIONS ................................. 6
INDICATOR QUICK REFERENCE .............................. 6
MULTI-CHANNEL AUDIO MIXING .............................. 7
MIXING AN EXTERNAL TAPE DECK WITH RECEIVER OUTPUT ...... 7
TROUBLESHOOTING ....................................... 8
REPLACEMENT PARTS and ACCESSORIES ..................... 9
SERVICE AND REPAIR ..................................... 10
RETURNING UNITS FOR REPAIR ............................. 10
SPECIFICATIONS AND FEATURES ............................ 11
LIMITED ONE YEAR WARRANTY .............................. 12
1
GENERAL DESCRIPTION
The R170 receiver utilizes a two stage quartz crystal oscillator to assure that the frequency will not drift.
Custom made high Q toroidal filters in the RF and IF stages reject interfering adjacent signals and
provide over 100 dB of image rejection. Dual gate MOS FET semi-conductors in the RF amplifier and
mixer provide excellent sensitivity and resistance to RF overload. A two stage, crystal controlled
oscillator is individually trimmed to the exact operating frequency when each receiver is manufactured
to insure that the frequency will not drift.
The audio section contains a noise reduction "compandor" to suppress audible noise without impairing
the natural dynamics of the audio signal. A 6-pole active filter in the audio path eliminates all
supersonic and subsonic noise in order to increase the compandor tracking accuracy in weak signal
conditions. A time delayed, correlation squelch system is employed in the R170. This circuit is highly
stable and never needs adjustment by the user.
A standard XLR jack provides a balanced 200 Ohm output, variable from -20dBm to -70dBm
(microphone level). A 1/4" phone jack provides a balanced 600 Ohm output, variable from 0dBm to
-50dBm (line level). An RCA phono jack provides a 1K Ohm output at 1 Volt maximum (line level) for
tape recorders or other PA systems. The output level control is a balanced "H" pad attenuator network
using precision resistors. It reduces the output of the XLR and 1/4" jacks, but does not affect the
output of the RCA jack. Noise and distortion are very low and not affected by the setting of the output
level control.
The CH-12 remote DC power supply isolates the R170 receiver audio circuitry from AC ground, which
eliminates ground loops. This also allows the R170 to be powered from external 12 Volt power sources
other than the CH-12 AC adapter.
The R170 receiver is compatible with all Lectrosonics 170 and 185 series transmitters.
2
RECEIVER FRONT PANEL
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 - VOLUME ATTENUATOR - An output attenuator is used to adjust the output level of the two
balanced outputs (XLR and 1/4") on the rear panel of the receiver. When the knob is in a fully clockwise position, the output at the jack will be 100mV when the signal is at full modulation. The attenuator
knob works like a regular volume control. As you turn the knob counter clockwise the audio output of
the receiver will be lowered.
NOTE: This control does not affect the MOD LEVEL display, the RF LED or the
POWER LED -- it also does not affect the output level of the "LINE OUT" RCA jack.
OFF - AUDIO MUTE - ON -- This slide switch turns the power off and on and provides a "mute"
function in the center position. This switch should be in the AUDIO MUTE position when the transmitter
MIC LEVEL or GAIN adjustment is being made. This muting function also prevents turn-on and turn-off
transients ("thumps" or "pops" in the sound system) that can occur when switching the receiver on and
off.
RF lamp -- Lights when the transmitter is turned on. If the carrier signal is too weak to produce a
quality signal, the lamp will go out.
POWER lamp -- Lights when the receiver is turned on.
Figure 1 - R170 Front Panel
3
RECEIVER REAR PANEL
ANTENNA terminal -- A standard PL 259 connector for mounting the A-185PL antenna, or connecting
the A-185Coax remote antenna.
12V DC INPUT -- Connect the power supply here -- the CH-12 AC adapter is supplied with the receiver
for powering the unit from a 110V AC outlet -- the receiver may also be powered from 12 Volt DC
sources using the correct plug; the center pin is positive(+). (Switchcraft S-760 power plug)
AUDIO OUTPUTS
BAL MIC LEVEL -- 3 pin XLR at microphone level (100mV max.); 200 Ohm impedance for either
balanced or unbalanced inputs
BAL 600 OHM -- 1/4" phone jack at "line" level (700mV max.); 600 Ohm impedance for either balanced
or unbalanced inputs
LINE OUT -- RCA phono jack at "line" level (1 Volt max.); 1K Ohm impedance for unbalanced inputs.
The output level of this RCA jack is not affected by the front panel VOLUME ATTENUATOR control.
AUDIO INPUT (mixing bus)
AUDIO IN -- RCA phono jack input accepts external tape deck or other audio source; mixes audio with
receiver output. Also allows "stacking" multiple receivers (see page 8).
Figure 2 - R170 Rear Panel
4
USE AND PLACEMENT
A wireless transmitter sends a radio signal out in all directions. Indoors, this signal will often bounce off
nearby walls, ceilings, etc. and a strong reflection can arrive at the receiver antenna along with the
direct signal. Outdoors, reflections can occur from nearby cars, trucks or metal buildings. If the direct
and reflected signals are out of phase with each other, a cancellation may occur. The result would be
a "drop out." A drop out sounds like either audible noise (hiss or hum as the transmitter is moved
around), or in severe cases, may result in a complete loss of the sound when the transmitter is
positioned in certain locations in the room. A dropout situation may be either better or worse as the
crowd fills and/or leaves the room, or when the transmitter or receiver is operated in a different location.
The illustration below depicts a simplified multi-path dropout. This drawing is overly simplified to
emphasize the phase cancellation that results in a low RF signal at the receiver antenna. In actual use,
there are numerous different paths that the radio signal can take simultaneously, causing a multitude of
different signals arriving at the receiver antenna. The high sensitivity of the R170 minimizes dropouts in
multi-path environments, since it will continue to operate with a usable audio signal to noise ratio even
with weak RF signal inputs.
Position the antenna so that it is not touching or within 3 or 4 feet of large metal surfaces. If this is not
possible, try to position the antenna so that it is as far away from the metal surface as is practical. It is
also good to position the receiver so that there is a direct "line of sight" between the transmitter and the
receiver antenna. In situations where the operating range is less than about 50 feet, the antenna
positioning is much less critical. In the event that you do encounter a dropout problem, first try moving
the receiver/antenna at least 3 or 4 feet from where it was. This may alleviate the dropout problem. If
dropouts are still a problem, try moving the receiver and/or the antenna to an entirely different location
in the room.
Lectrosonics transmitters radiate power very efficiently, and the receivers are very sensitive. This
reduces dropouts to an insignificant level. If, however, you do encounter dropouts frequently, call the
factory. There is probably a simple solution.
Figure 3 - Antenna Placement
5
OPERATING INSTRUCTIONS
SET UP AND OPERATION SEQUENCE
1) CONNECT POWER CORD -- Plug the connector into the jack labeled "12 VDC ". Insert the plug
fully into the jack.
2) ATTACH AND EXTEND THE ANTENNA FULLY
3) CONNECT THE AUDIO CABLE/S
A. For playback from a tape player, plug into "AUDIO IN"
B. The sound system plugs into "BAL MIC"
C. An alternate plug for the sound system is "HI Z BAL"
D. To record, plug a tape recorder into "LINE OUT". Multi-channel applications are also possible
using "LINE OUT" and "AUDIO IN".
4) SET FRONT PANEL SWITCH TO "AUDIO MUTE"
Check to see that the red POWER LED lights up
5) ADJUST TRANSMITTER "MIC LEVEL" (See transmitter manual)
This is perhaps the most important step in the set up procedure. See your transmitter manual for
specific instructions on the proper gain adjustment of your transmitter. With some transmitter
models you will need to observe the MOD LEVEL LED’s on the receiver front panel as you adjust
the gain on the transmitter.
6) SET FRONT PANEL SWITCH TO "ON" POSITION
7) SET THE OUTPUT VOLUME ATTENUATOR KNOB IN THE MIDDLE OF THE "NORMAL"
RANGE
The input levels on different recording and PA equipment vary. Try different settings and listen to
the results. The volume attenuator works like a basic volume control knob. If the output of the
receiver is too high, you may hear distortion or a loss of the natural dynamics of the audio signal.
Turn the control knob down or counter clockwise. If the output is too low, you may hear steady
noise (hiss or hum) along with the audio. Turn the control knob up or clockwise from the midpoint
of the normal range.
INDICATOR QUICK REFERENCE
RF -- Lights up when the transmitter is turned on. This indicates that the receiver is getting an
adequate RF signal (carrier) from the transmitter.
POWER -- Lights up when the receiver is properly connected to a power supply and switched on.
TRANSMITTER MOD LEVEL -- The green LED lights up when an audio signal is present at a high
enough level to produce a good signal to noise ratio. The red LED lights up when the audio level is too
high and is being compressed in the transmitter. Extremely high audio levels may cause distortion. A
very low audio level will produce a poor signal to noise ratio (audible hiss will be heard along with the
sound).
REVIEW THE TRANSMITTER INSTRUCTION MANUAL FOR PROPER ADJUSTMENT OF THE
TRANSMITTER MIC LEVEL OR GAIN
6
MULTI-CHANNEL AUDIO MIXING
The R170 receiver offers a unique feature that eliminates the necessity of using an external audio mixer
in multi-channel applications. When using two or three R170 receivers together, the LINE OUT and
AUDIO IN 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.
Connect the LINE OUT jack of one receiver to the AUDIO IN jack of the next receiver, then connect its
LINE OUT jack to the AUDIO IN jack of the next receiver, forming a "chain" as shown in the illustration.
Up to three (3) receivers may be interconnected in this manner (combining the audio outputs of all
three) so that a single audio output is available from the output of the last receiver in the "chain".
The output level of the LINE OUT RCA jack is not affected by the VOLUME ATTENUATOR control.
The VOLUME ATTENUATOR control on the last receiver in the "chain" will control the combined
volume of all the receiver outputs. In order to control the receiver outputs independently, you will need
to use an external microphone mixer without the "jumper" cords shown below.
MIXING AN EXTERNAL TAPE DECK WITH RECEIVER OUTPUT
A tape player may be connected to the AUDIO IN jack on the rear panel to mix the tape player output
with the receiver output. Adjust the volume of the tape player with the volume control on the tape
player since there is not a separate control for this purpose on the receiver.
7
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.
3) Mic capsule is damaged or malfunctioning.
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 labels on transmitter and receiver.
5) Operating range is too great.
NO SOUND AND RECEIVER MOD LEVEL LEDs ARE OFF
Transmitter audio muted. Check to see that the
audio is not muted on your transmitter, if this
feature is available on your model transmitter.
NO SOUND BUT RECEIVER MOD LEVEL LEDs ARE ON
1) Receiver audio is muted. Refer to receiver
manual.
2) Receiver audio output is disconnected or cable is
defective or mis-wired.
3) Sound system or recorder input is turned down.
DISTORTED SOUND
HISS AND NOISE -- AUDIBLE DROPOUTS
EXCESSIVE FEEDBACK
1) Transmitter gain (audio level) is too high. Speak
or sing into the transmitter and check mod level
lamps on transmitter and receiver.
2) Receiver output may be mis-matched with the
sound system or recorder input.
3) Excessive wind noise or breath "pops."
1) Transmitter gain (audio level) too low.
2) Receiver antenna missing or obstructed.
3) Operating range too great.
1) Transmitter gain (audio level) too high. Check
gain adjustment and/or reduce receiver output.
2) Transmitter too close to speaker system.
3) Transmitter too far from the user’s mouth.
8
REPLACEMENT PARTS and ACCESSORIES
Part No. Description
CH-12 110 Volt AC adapter for R170 receiver
A-185PL Swivel-mount antenna with PL259 connector
A-185Coax Remote coaxial cable antenna
CCFP Molded carrying case for wireless systems
MM-18 18" male RCA to male RCA cord for "stacking" receivers (see page 7)
9
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. If the repair is more complicated than a
broken wire or loose connection, send the unit to the factory for repair and service. Don’t attempt to
adjust any controls inside the units. Once set at the factory, the various controls and trimmers do not
drift with age or vibration and never require readjustment. There are no adjustments inside that will
make a malfunctioning unit start working.
LECTROSONICS service department is equipped and staffed to quickly repair your equipment.
In-warranty repairs are made at no charge in accordance with the terms of the warranty. Out of
warranty repairs are charged at a modest flat rate plus parts and shipping. Since it takes almost as
much time and effort to determine what is wrong as it does to make the repair, there is a charge for an
exact quotation. We will be happy to quote approximate charges by phone for out of warranty repairs.
RETURNING UNITS FOR REPAIR
You will save yourself time and trouble if you will follow the steps below:
A. DO NOT return equipment to the factory for repair without first contacting us by letter or by phone.
We need to know the nature of the problem, the model number and the serial number of the
equipment. We also need a phone number where you can be reached 8 am to 4 pm (Mountain
Standard Time).
B. After receiving your request, we will issue you a return authorization number (R.A.). This number
will help speed your repair through our receiving and repair departments. The return authorization
number must be clearly shown on the outside of the shipping container.
C. Pack the equipment carefully and ship to us, shipping costs prepaid. If necessary, we can provide
you with the proper packing materials. UPS is usually the best way to ship the units. Heavy units
should be "double-boxed" for safe transport.
D. We also strongly recommend that you insure the equipment, since we cannot be responsible for
loss of or damage to equipment that you ship. Of course, we insure the equipment when we ship
it back to you.
Mailing address: Shipping address:
Lectrosonics, Inc. Lectrosonics, Inc.
PO Box 15900 581 Laser Rd.
Rio Rancho, NM 87174 Rio Rancho, NM 87124
USA USA
Telephones:
Regular: (505) 892-4501
WATS: (800) 821-1121
FAX: (505) 892-6243
10
SPECIFICATIONS AND FEATURES
R170 RECEIVER
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 flat; 100 dB A-weighted
Squelch quieting: greater than 100 dB
AM rejection: -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.
* ¼ inch: 600 Ohm; 700 mV max.
(500 mV max. unbalanced)
* RCA: 1k Ohm unbalanced; 1 Volt max.
Audio input: RCA jack for unity gain audio mixing bus
Antenna input: PL259 female; 50 Ohm impedance
Controls: Front panel attenuator controls balanced outputs; 3
position power/function switch
Indicators: LED for power "ON"
2 LEDs for modulation level
"RF" LED for transmitter "ON"
Power requirements: * 12 Volt DC direct to panel mounted jack
* 110 Volt AC via CH-12 AC adapter
Power consumption: 125 mA max.
Weight: 2.1 lbs
Dimensions: 2.9 x 7.4 x 5.3 inches
11
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. If we cannot
correct the defect in your equipment, we will replace it at no charge
with a similar new item. We will pay for the cost of returning your
merchandise to you.
This warranty applies only to items returned to us, shipping costs
prepaid, within one year from the date of purchase.
This warranty gives you specific legal rights. You may have additional
legal rights which vary from state to state.
LECTROSONICS, INC.
581 LASER ROAD
RIO RANCHO, NM 87124 USA December 17, 1993
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