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UH200C
FREQUENCY-AGILE
PLUG-ON UHF TRANSMITTER
OPERATING INSTRUCTIONS
and trouble-shooting guide
LECTROSONICS, INC.
Rio Rancho, NM
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INTRODUCTION
Thank you for selecting the Lectrosonics UH200C frequency agile, plug-on transmitter. The
UH200C 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 UH200C was the direct result of numerous conversations with users, staging
and touring companies and dealers across the US. The specific concerns and needs brought
up in these conversations led directly to the development of the operational features offered on
the UH200C. Two hundred fifty six frequencies are user selectable in 100kHz steps to alleviate
interference problems in travelling venues.
The UH200C is a rugged, machined aluminum package. Phantom power is provided on pins 2
and 3. Level indicating LEDs are provided to make level settings quick and accurate, without
having to view the receiver. The battery compartment accepts any 9 Volt alkaline or lithium
battery and makes a positive connection via self-adjusting contacts.
Only the UH200C transmitter is covered in this manual. Companion receivers are covered in
separate manuals. The UH200C will operate with any 200 Series Lectrosonics receiver in the
same frequency group.
TABLE OF CONTENTS
INTRODUCTION .....................................................................................................2
GENERAL TECHNICAL DESCRIPTION ...............................................................3
CONTROLS AND FUNCTIONS .............................................................................4
OPERATING INSTRUCTIONS ..............................................................................5
OPERATING NOTES .............................................................................................5
ADJUSTING THE TRANSMITTER FREQUENCY ................................................5
TROUBLESHOOTING ............................................................................................ 6
BATTERY REPLACEMENT ...................................................................................6
SPECIFICATIONS AND FEATURES ..................................................................... 8
SERVICE AND REPAIR .........................................................................................9
RETURNING UNITS FOR REPAIR .......................................................................9
WARRANTY ........................................................................................... Back cover
The UH200C transmitter is FCC type accepted under Part 74: 470 - 608MHz and 614 - 806MHz
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Frequency Agile Plug-on UHF Transmitter
GENERAL TECHNICAL DESCRIPTION
The UH200C transmitters are comprised of a number of functional sub-systems as shown in the block diagram below.
GENERAL
The 200 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 (6.5 Volts) of battery life. The input amplifier uses an
ultra low noise op amp. It is gain controlled with a wide range
input compressor which cleanly limits input signal peaks over
30dB above full modulation.
DUAL BAND COMPANDOR
Traditionally, compandors have been a source of distortion in
wireless microphone systems. The basic problem with conventional systems is that the attack and decay times are always a
compromise. If the time constants are fast, high frequency
transients will not be distorted, but this will cause low frequency
distortion. If the time constants are slower, low frequency audio
distortion will be low, but high frequency transients will then be
distorted. The 200 system introduces an entirely new approach
to solving this basic problem, called “dual-band companding.”
There are actually two separate compandors in the 200 system,
one for high frequencies and one for low frequencies. A crossover network separates the frequency bands at 1kHz with a 6dB
per octave slope, followed by separate high and low frequency
compandors. The attack and release times in the high frequency compandor are fast enough to keep high frequency
transient distortion at a low level, and the low frequency
compandor uses slower time constants, reducing low frequency
distortion to well below that of a conventional compandor.
NO PRE-EMPHASIS/DE-EMPHASIS
The signal to noise ratio of the 200 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.
MIC
SHUNT
LIMITER
+5V BIAS
SUPPLY
BUFFER
LIMIT
LED
SET
LED
INPUT
AMP
PEAK AUDIO
INDICATOR &
LIMITER
DRIVER
AUDIO
LEVEL
LP
FILTER
Vref
COMPANDOR
BASS
TREBLE
LP FILTER
HP FILTER
JACK
Pre-emphasis can also cause distortion in the receiver. As this
signal is passed through the IF filters in the receiver, distortion
can be produced, most noticeable at full modulation. Deemphasis cannot be applied until the signal is converted into
audio, so there is no way around this problem short of eliminating pre-emphasis altogether. Neither of these problems occur
in the 200 system. The dual-band compandor in the 200 Series
system essentially provides a dynamic pre-emphasis/de-emphasis function with extremely low distortion.
PILOT TONE SQUELCH
The 200 system utilizes an ultrasonic tone modulation of the
carrier to operate the receiver squelch. This “pilot tone” consists of a 32kHz signal mixed with the audio signal after the
compandor, to control the audio output muting of the receiver.
The pilot tone is filtered out of the audio signal immediately after
the detector in the receiver so that it does not influence the
compandor or various gain stages. The basic benefit of the pilot
tone squelch system is that the receiver will remain muted until it
receives the pilot tone from the matching transmitter, even if a
strong RF signal is present on the carrier frequency of the
system. This is extremely important in applications that include
an automatic microphone mixer.
WIDE-BAND DEVIATION
±75kHz deviation improves the capture ratio, signal to noise
ratio and AM rejection of a wireless system dramatically, compared to the more commonly used ±15kHz deviation.
LONG BATTERY LIFE
High efficiency circuits throughout the design allow over 4.5
hours of operation using a single 9 Volt alkaline battery. (A 9V
lithium battery will provide over 12 hours of operation.) The
battery compartment is a unique mechanical design which automatically adjusts to fit any brand of battery. The battery contacts
are spring loaded to prevent “rattle” as the unit is handled.
FREQUENCY AGILITY
The transmitter section uses a synthesized, frequency selectable main oscillator. The frequency is extremely stable over a
wide temperature range and over time.
Two rotary switches, located on the side panel of the unit,
provide 256 frequencies in 100kHz steps over a 25.5MHz range.
This alleviates carrier interference problems in mobile or travelling applications.
COMPANDED AUDIO
TO XMTR
PILOT
TONE
Vreg
Vreg
OSC
+5VDC
+3.6VDC
MUTE
PWR
+9VDC
PWR
LED
PHASE LOCKED LOOP
DIVIDER
FREQ
SWITCHES
PRESCALER
LOW PASS
FILTER
COMPANDED
AUDIO
VOLTAGE
CONTROLLED
OSCILLATOR
TRANSMITTER
Rio Rancho, NM – USA
UH200C Block Diagram
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CONTROLS AND FUNCTIONS
The UH200C may be used with a wide variety of microphones.
The 3-pin XLR connector on the UH200C allows the transmitter
to be used with any dynamic microphone, as well as many two
wire positive bias lavalier systems (such as those systems supplied by Lectrosonics).
INPUT JACK
Standard 3-pin Switchcraft XLR type. Pin 2 is signal, pin 3 is a
floating signal ground, and pin 1 is case ground (see schematic
below). The UH200C is self-locking onto a standard microphone.
The XLR connector is permanently bonded to the metal collar,
and is not normally replaceable. The electret bias is 5 Volts at
1mA or less. The bias is connected in a “phantom” manner and
will not interfere with any standard balanced microphone. If
severe noise is experienced when the microphone is moved
with respect to the UH200C, the cause is an unbalanced
condition between pins 2 and 3 of the microphone.
To Mic
1uh
1uh
2
1
3
1uh
1K
Preamp
100
+5V
100uf
LIMIT LED
LEVEL LED
BATTERY
POWER
LED
MUTE
OFF
ON
TOP VIEW
LEVEL
CONTROL PANEL
Please note that a weak battery will sometimes light the POWER
LED immediately after turn on, but soon will discharge to the
point where the LED will extinguish.
The combination of an accurate battery condition indicator and
regulation of all internal circuits guarantees much longer battery
life, as well as consistent performance versus battery life.
MODULATION LEDS: Indicate the proper setting of the MIC
LEVEL control.
LEVEL LED: Flickers or glows most of the time if the audio
volume is adequate for normal operation.
LIMIT LED: Lights up when the audio volume is high, indicating
that the signal level is being limited by the compressor. Optimum signal-to-noise ratio is obtained when the limit LED lights
occasionally.
Input Jack Schematic
POWER/MUTE SWITCH
Turns the battery power on and off. Even when the switch is
turned off or on abruptly, the pilot tone muting system prevents
“thumps” or transients from occurring.
The center position is an “audio mute” which should be used
when setting the MIC LEVEL control. The “mute” position shuts
down the pilot tone in the transmitter and allows you to adjust
the audio modulation level without the possibility of feedback.
POWER ON/OFF LED
Glows brightly when battery is good. A weak or dim LED means
that the battery is weak, and has about an hour of operation left.
If the LED fails to light, the battery should be replaced. The
power LED should light up in both the “mute” and “on” positions
of the POWER/MUTE SWITCH.
The POWER LED is connected to a precision battery test circuit
that continuously monitors battery voltage. The LED is at full
brightness with a new 9 Volt alkaline battery. As the battery
voltage drops during use, the LED brightness will also decrease.
After 4.5 hours the battery voltage will be about 7 Volts. The
LED will be completely extinguished. 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.
MIC LEVEL: Used to adjust the audio input volume for the
proper modulation level. Rotate knob until the LEVEL LED
flickers when there is an input signal. The LIMIT LED should
light occasionally.
FREQUENCY ADJUST
These two rotary switches adjust the center frequency of the
carrier. The 1.6M is a coarse adjustment and the 100K is the
fine adjustment. Each transmitter is factory aligned at the
center of its operating range. The default position of the frequency select switches is in the center of the transmitter’s
range.
0
1
F
E
D
C
B
A
2
3
4
5
6
9
7
8
0
1
F
E
D
C
B
A
2
3
4
5
6
9
7
8
Frequency select switches, default position (8,8)
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Frequency Agile Plug-on UHF Transmitter
OPERATING INSTRUCTIONS
1) Insert the UH200C into the selected microphone. Listen for
the “click” that indicates the UH200C has locked on to the microphone. Pull on the mic to insure proper locking has occurred.
TO ATTACH
Press firmly, listen for click.
Depress collar fully.
Pull on mic to insure locking.
Attaching the Microphone
2) Turn the power switch to the “MUTE” position.
3) Hold the microphone as you will when you will be using it.
4) Position the microphone in the location you will use in actual
operation.
5) While speaking or singing at the same voice level that will
actually be used, observe the MODULATION LEDs. Adjust the
AUDIO LEVEL control knob until the LEDs begin to light. Start
at a low setting where neither LED lights as you speak. Gradually, turn the gain up until one LED lights, then the other.
The -20 LED lights when the audio level is about 20dB below full
modulation. The “0” LED lights when the limiter begins to
operate. There is over 30dB of limiting range without overload
above the “0” LED, so it is desirable that the it lights up occasionally during use.
6) Once the gain has been adjusted, the audio system audio can
be turned on to make level adjustments. Set the power switch to
the ON position and adjust the receiver and/or sound system
level as required. Please note, there will be a delay between
the moment the switch is thrown and the time when audio
will actually appear at the receiver output. This intentional
delay eliminates turn on thumps, and is controlled by the pilot
tone squelch control.
The first LED turns on 20dB below full deviation. The “0” LED
turns on at full deviation and indicates that the input shunt
compressor is operating. The input limiter will handle peaks
over 30dB above full modulation, regardless of the gain control
setting. The limiter uses a true absolute value
circuit to detect both positive and negative
Hold the
transmitter
case and
rotate the
collar in the
direction
shown. Do
this over a
soft surface
as the
microphone
may pop off
suddenly
peaks. The attack time is 5 milliseconds and
the release time is 200 milliseconds. Occasional limiting is desirable, indicating that the
gain is correctly set and the transmitter is fully
modulated for optimum signal to noise ratio.
Different voices will usually require different
settings of the AUDIO LEVEL control, so check
this adjustment as each new person uses the
system. If several different people will be using
the transmitter and there is not time to make
TO REMOVE
the adjustment for each individual, adjust it for
the loudest voice.
ADJUSTING THE TRANSMITTER
FREQUENCY
If you are experiencing interference from another signal on your
frequency, you may want to change the operating frequency of
your system. The left switch changes the operating frequency
by 1.6 MHz per step and the right switch changes it 100 kHz per
step. If you are experiencing interference, change the operating
frequency in 100 kHz steps to find a clear channel. If it is not
possible to find a clear channel using the 100 kHz switch, return
it to its original position and change the 1.6 MHz switch by one
click then try the 100 kHz switch again.
0
1
F
E
D
C
B
A
2
3
4
5
6
9
7
8
To gain access to these switches, slide the access door sideways with a fingernail.
0
1
F
E
D
C
B
A
2
3
4
5
6
9
7
8
OPERATING NOTES
The AUDIO 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.
If the audio level is too high -- both LEDs will light frequently or
stay lit. This condition may reduce the dynamic range of the
audio signal.
If the audio level is too low -- neither LED will light, or the -20
LED will light dimly. This condition may cause hiss and noise in
the audio, or pumping and breathing in the background noise.
Rio Rancho, NM – USA
Note: With the UDR200A receiver, these switches also appear
on the front panel of the receiver. Normally, you should set the
transmitter switches to match the receiver switch settings. The
switches are located on the rear panel of the UCR200D
receiver.
With the UDR200B receiver, the front panel LED character
display will indicate the correct transmitter switch settings.
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BATTERY REPLACEMENT
The UH200C 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 batteries marked “heavy duty” or “long-lasting” are not adequate.
They will provide only about 5 minutes of operation. Similarly,
nicad rechargeable batteries only give 1 hour of operation, and
will also run down quite abruptly. Alkaline batteries provide
about 4.5 hours of operation while lithium batteries will run the
unit for about 12 hours.
To open the battery compartment, press outward on the cover
door in the direction of the arrow as shown in the drawing. Only
slight, sliding pressure is needed to open and close the battery
door.
RELEASE
DOOR
SWING OPEN
Swing the door open and take note of the polarity marked inside
showing the location of the positive (+) and negative (-) terminals. Insert the battery and close the cover by pressing in and
across, reversing the opening procedure outlined above. Note
that the battery door will NOT close if the battery is inserted
incorrectly, since the terminals will hit a protective polarity barrier.
Don’t force the battery door closed. If it is difficult to close, the
battery is in backwards.
OBSERVE
POLARITY
Battery Compartment Action
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.
NO TRANSMITTER MODULATION LEDs 1) Gain control turned all the way down.
2) Battery is in backwards. Check power LED.
3) Mic capsule is damaged or malfunctioning.
4) Mic cable damaged or mis-wired.
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Frequency Agile Plug-on UHF Transmitter
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.
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.
3) Sound system input is turned down.
NO SOUND (OR LOW SOUND LEVEL),
RECEIVER MOD LEDs ARE OFF 1) Transmitter gain (audio level) set too low.
2) Faulty microphone
3) Transmitter power switch set to MUTE.
DISTORTED SOUND 1) Transmitter gain (audio level) is far too high. Check mod level
lamps on transmitter and receiver as it is being used. (Refer to
the Operating Instructions section for details on gain adjustment)
2) Receiver output may be mis-matched with the sound system or
recorder input. Adjust output level on receiver to the correct level
for the recorder, mixer or sound system.
3) Excessive wind noise or breath “pops.”
and/or use a larger windscreen.
Re-position microphone
Check switches/
4) Transmitter is not set to same frequency as receiver. Check that
frequency select switches on receiver and transmitter match.
HISS AND NOISE – AUDIBLE DROPOUTS 1) Transmitter gain (audio level) far too low.
2) Receiver antenna missing or obstructed.
3) Operating range too great.
EXCESSIVE FEEDBACK 1) Transmitter gain (audio level) too high causing the limiter to reduce
the dynamic range which in turn causes feedback. Check gain
adjustment and/or reduce receiver output level. (Refer to the
Operating Instructions section for details on gain adjustment)
2) Transmitter too close to speaker system.
3) Mic is too far from user’s mouth.
Rio Rancho, NM – USA
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SPECIFICATIONS AND FEATURES
Operating frequencies:
Frequency selection:
RF Power output:
Pilot tone:
Frequency stability:
Deviation:
Spurious radiation:
Equivalent input noise:
Input level:
Input impedance:
Input compressor:
Gain control range:
470 to 608 MHz, 614 to 806 MHz
256 frequencies in 100kHz steps
100 mW (nominal)
32.764 kHz (± 2Hz); 5kHz deviation
± 0.002%
± 75 kHz (max)
90 dB below carrier at frequencies less than 1GHz
-126 dBV
Nominal 2 mV to 300 mV, before limiting.
Input greater than 2V, with limiting.
1K Ohm mic load impedance
Soft compressor, >30 dB range
43 dB; semi-log rotary control
Modulation indicators:
Controls:
Audio Input Jack:
Battery:
Battery Life:
Weight:
Dimensions:
Emission Designator:
Dual LEDs indicate modulation level 12 dB below limiting and at the
onset of limiting.
3-position “OFF-MUTE-ON” slide switch for noiseless turn on/turn
off operation. Control panel knob adjusts audio gain. Rotary
switches on side panel adjust transmitter frequency.
3-Pin XLR
Precision compartment auto-adjusts to accept any known alkaline
or lithium 9 Volt battery. (We’ve tried 150 different ones!)
4.5 Hours with alkaline 9 Volt, 12 hrs with lithium
6.6 ozs. including battery
1.5 x 1.5 x 4.2 inches
180KF3E
Specifications subject to change without notice.
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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. Check out the interconnecting 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:
Lectrosonics, Inc.
PO Box 15900
Rio Rancho, NM 87174
USA
World Wide Web: http://www.lectrosonics.com Email: sales@lectrosonics.com
Shipping address:
Lectrosonics, Inc.
581 Laser Rd.
Rio Rancho, NM 87124
USA
Telephones:
Regular: (505) 892-4501
Toll Free (800) 821-1121
FAX: (505) 892-6243
Rio Rancho, NM – USA
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LIMITED ONE YEAR WARRANTY
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, Lectrosonics, Inc. will, at our option, repair or replace any
defective parts without charge for either parts or labor. If Lectrosonics, Inc. cannot
correct the defect in your equipment, it will be replaced at no charge with a similar new
item. Lectrosonics, Inc. will pay for the cost of returning your equipment to you.
This warranty applies only to items returned to Lectrosonics, Inc. or an authorized
dealer, shipping costs prepaid, within one year from the date of purchase.
This Limited Warranty is governed by the laws of the State of New Mexico. It states the
entire liablility of Lectrosonics Inc. and the entire remedy of the purchaser for any
breach of warranty as outlined above. NEITHER LECTROSONICS, INC. NOR
ANYONE INVOLVED IN THE PRODUCTION OR DELIVERY OF THE EQUIPMENT
SHALL BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, CONSEQUENTIAL,
OR INCIDENTAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THIS EQUIPMENT EVEN IF LECTROSONICS, INC. HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES. IN NO EVENT SHALL THE LIABILITY OF
LECTROSONICS, INC. EXCEED THE PURCHASE PRICE OF ANY DEFECTIVE
EQUIPMENT.
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
November 12, 2001
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