Comtek Communications Technology M175 Personal body-worn communication transmitter User Manual C 175rpt tableofcontent wpd
Comtek Communications Technology Inc Personal body-worn communication transmitter C 175rpt tableofcontent wpd
User Manual
M-175 OPERATOR’S MANUAL (PRELIMINARY)
357 West 2700 South • Salt Lake City, Utah 84115 • Phone: (800) 496-3463 • Fax: (801) 484-6906 • http://www.comtek.com
M-175
Personal
Communication
Transmitter
© 2007 COMTEK® All rights reserved.
Printed in the U.S.A. 0107M175
TABLE OF CONTENTS
Introduction ...........................................................
Setup ...............................................................................
Controls ..................................................................
Battery Removal
/
Replacement ......................................
Battery Charging ......................................................
Auxiliary Audio Input Operation ...................................
Snap-On Belt Clip .................................................
Frequency Selection ..............................................
Frequency Information .........................................
Optional Accessories ............................................
Specifications .........................................................
Warranty and Service ..................................................
1
2
3
4
5
6-7
7
8
9
10
11
12
INTRODUCTION
Page 1
The M-175 transmitter offers the
ultimate performance and
versatility for applications where
one-way personal communication is
required. This compact, personal
transmitter is ideal for instructors and
presenters who must communicate
with persons some distance away or
in a noisy environment.
The M-175 incorporates the latest digital
and analog technologies to produce low
residual noise, wide dynamic range, and
extended frequency response rendering
the most natural sound possible from a
personal communications system.
The audio processing circuit produces
full fidelity frequency response from
100 Hz to 10 kHz in the companded
or non-companded mode to
accommodate a greater variety of
receivers. Operating under F.C.C.
Regulation Part 90 allows a
greater transmission range and
reliability than is customary
with 72-76 MHz systems.
M-175
Personal
Communication
Transmitter
Setup
a. Check to ensure that the M-175 transmitter’s radio frequency channel is
the same as the associated COMTEK receiver’s channel.
(Channels are indicated by the rotary channel selector switches on the back
of the transmitter. See page 8.)
b. Open the battery door cover on the transmitter (see page 4) and
insert a new nine volt alkaline battery (Eveready E522 or equivalent).
This type of battery will offer up to 16 hours of operation. Replace the battery
before every use if the demand for fail-safe operation outweighs battery cost. The use
of carbon batteries is not recommended.
NOTE: If a rechargeable battery is to be used, ensure that it has been
allowed to charge at least twelve hours to bring it to full charge
(see page 5 for battery charger instructions).
c. Connect the microphone to the transmitter by inserting the microphone
plug into the receptacle on the top of the transmitter. The transmitter is
operating when the transmitter power switch is turned on and the battery
status/on indicator illuminates.
NOTE: The 48-inch microphone cord also functions as part of the
transmitter’s antenna system. For optimum performance, this cord
should be fully extended. Coiling or bunching the microphone
cord may reduce the range of the transmitter. The transmitter
should be carried by the snap-on belt clip (included) or in a pocket
or belt-clip pouch.
d. In a situation where an extremely loud voice or a very soft voice is used, it
is necessary to adjust the audio input gain control while observing the audio
“voice” level modulation indicator. A full bright LED indicates full audio
compression at 100% modulation. For best performance, the audio input
gain should be adjusted for some low level LED luminescence during
normal audio levels with occasional full bright peaks indicating 100%
modulation.
M-175 SETUP
Page 2
Page 3
M-175 CONTROLS
n COMPAND AUTO / OFF SWITCH: This switch overrides
the automatic selection of the companded channels to
non-companded operation.
o CHANNEL SWITCHES: These rotary
switches are used to set the transmitter to the
desired operating frequency.
(See page 9 and 10 for frequency selection chart.)
p BATTERY COMPARTMENT: The
battery compartment features a hinged
battery cover and an alignment system that
ensures proper battery polarity. Battery
installation and removal is facilitated by simply
manipulating the bottom of the battery.
q AUXILIARY AUDIO INPUT JACK:
Allows transmitter to use line level, earphone
level, or fixed AUX as an audio source.
r AUDIO “VOICE” MODULATION INDICATOR:
This indicator is used in making adjustment with the
Audio Input Gain Control.
s MIC / ANTENNA JACK: This jack accepts an
electret type microphone having a 48” long cord with
a micro-mini 2.5mm mono plug. The microphone cord
functions as part of the transmitter’s antenna system
and must be in place for auxiliary audio input operation.
If microphone function is not necessary, the optional
microphone switch should not be on for this operation.
t POWER / BATTERY STATUS INDICATOR: This LED indicator will illuminate
continuously when the unit is on, indicating normal operation. When the battery voltage
drops below 6 volts, the LED will flash rapidly, indicating that a new battery is needed.
u OPTIONAL MIC SWITCH: This switch turns off the microphone without turning off
the transmitter carrier.
v AUDIO INPUT GAIN CONTROL: This is a microphone and AUX level input gain
control. This control is used with the “Voice” modulation indicator.
w ON / OFF SWITCH: This switch turns the transmitter on and off.
Page 4
Low Battery Indicator
The LED on the top of the transmitter
indicates the status of the battery as
well as indicating that the unit is turned
on. When the transmitter is turned on,
the LED illuminates. If the battery is low,
the green LED will blink rapidly to warn
you that the battery will soon be dead.
Replace a low battery immediately.
M-175 BATTERY REMOVAL / REPLACEMENT
Pull back battery door latch and allow battery
cover door to spring open. To remove battery,
simply manipulate the bottom of battery out of
the compartment and remove.
To insert battery, face battery
with negative terminal in line with
large hole in battery compartment,
press battery into compartment and close
battery door until it snaps shut. Note: It is not
possible to put battery in backwards.
Battery indicator LED
Battery Removal / Replacement
Page 5
M-175 BATTERY CHARGING
Battery Charging
1. Make sure that a seven cell 9 volt Ni-MH rechargeable
battery is used with a minimum of 200 mAh capacity.
(Alkaline batteries must not be charged.)
2. Make sure the M-175 is turned OFF.
3. Note that the red charging indicator on the charger is ON when the M-175
is plugged into the charger through the audio output jack.
4. When using the NBC 9-2C charger allow the battery to charge for 14 hours
for a full charge. Unit must then be unplugged. When using the
NBC 9-3-1 digital fast charger the charger will automatically end the
charge cycle and the red LED will change to green. With this charger
the unit may be left in the charger until the unit is used.
5. Periodically open the battery compartment on stored COMTEK units to
check for battery leakage. If a battery is leaking, it must be discarded,
and the battery compartment must be cleaned or returned to COMTEK’s
service department for repairs.
IMPORTANT
NBC 9-2C
14-hour charger NBC 9-3-1
digital fast charger
Page 6
M-175 AUXILIARY AUDIO INPUT OPERATION
Auxiliary Audio Input Operation
The M-175 transmitter may transmit a variety of audio sources such as tape
and C.D. players, TV and VCR’s, or any audio device having an auxiliary or
line level audio output.
The auxiliary input cable supplied with the M-175
transmitter (CB-36 ST) will operate with any device
having a mini 3.5 mm jack, stereo or mono, and
with line level or earphone level output.
To accommodate a variety of specialty
applications, auxiliary input cables
with RCA phono plug, 1/4” audio
phone plug, and XLR connectors are
available from COMTEK.
Setup
a. Connect the microphone
to the transmitter by
inserting the microphone
plug into the receptacle on
the top of the transmitter.
Note: The microphone
cord functions as part of the
transmitter’s antenna system
and must be in place for auxiliary
audio input operation. If microphone
function is not necessary, the optional microphone
switch should not be on for this operation.
b. Connect the proper auxiliary input cable to the audio source. Connect the
right-angle mini plug end of the auxiliary input cable in the “AUX” input
jack of the M-175 transmitter.
Note: Check to ensure that the audio source is a line level, earphone level,
or fixed AUX level output.
Page 7
Belt clip installation
M-175 SNAP-ON BELT CLIP (Included)
Belt clip removal
c. Turn on the transmitter with program from the audio source being fed to
the transmitter. Observe the audio “voice” level modulation indicator. A full
bright LED indicates full audio compression at 100% modulation. For best
performance, the audio input gain should be adjusted for some low level
LED luminescence during normal audio levels with occasional full bright
peaks indicating 100% modulation.
d. When using the auxiliary audio input with the microphone plugged into
the transmitter, priority should be given to the microphone gain adjustment.
The mixing balance between the auxiliary audio and the microphone should
be made with the volume control of the auxiliary audio source.
Note: The optional microphone switch only affects the
microphone. It does not affect the auxiliary audio input.
M-175 AUX OPERATION (Cont.) / SNAP-ON BELT CLIP
STEP 1:
Hook belt clip
retaining lip over
front case ridge.
STEP 2:
Rotate belt clip down onto case. Apply
pressure on both sides of clip, snapping
clip retainers into slots.
Clip retainer
Retainer slot Belt clip removal indent
Flex out and pull down with your
thumb or a large coin (quarter) to
unsnap belt clip from case.
Page 8
Frequency Selection (72-76 MHz)
The M-175 transmitter can operate on one of 88 available channels
between 72-76 MHz. COMTEK channel designations indicate a specific
frequency which can be used in the companded or non-companded
mode of operation. When the “compand auto/off switch” is in the “auto”
position, the M-175 transmitter must be used only with receivers having 2:1
audio companding processing. When the “compand Auto/Off switch”
is in the “off” position, standard non-companded receivers must
be used.
After you have determined the channel on which
you are going to operate, position the two rotary
switches to indicate the channel. The left rotary
switch is for tens and the right rotary switch is for
ones. To select channel 41 (72.92 MHz), position
the left rotary switch to point to 4 (X10), and
position the right rotary switch to point to 1 (X1).
Refer to frequency charts on pages 9 and 10 for selectable frequencies.
Multiple Channel Operation
When multiple transmitters are broadcasting in the same immediate area
(within 100 feet), the RF signals will “mix” together generating additional
signals. If these product frequencies are too close to a frequency which you are
using, you will experience intermodulation interference. This condition is
common to all radio receivers to some extent.
Simultaneous operation of more than three channels requires frequency
coordination to avoid intermodulation interference which could result in
poor or unusable performance.
To avoid this type of interference, you should select frequencies from one of
the standard groups (see group frequency charts on pages 9 and 10), or use
COMTEK’s frequency selection software available at www.comtek.com to
determine appropriate frequencies or contact COMTEK to obtain a free copy.
M-175 FREQUENCY SELECTION
Compand Switch
Page 9
M-175 FREQUENCY INFORMATION
GROUP 1
GROUP 2
GROUP 3
CHAN FREQ
72.02 MHz
72.22 MHz
72.72 MHz
74.61 MHz
75.62 MHz
75.72 MHz
01
11
31
45
70
75
CHAN FREQ
72.08 MHz
72.18 MHz
72.72 MHz
74.77 MHz
75.58 MHz
75.92 MHz
04
09
31
53
69
85
CHAN FREQ
13
25
54
57
81
87
72.26 MHz
72.58 MHz
74.79 MHz
75.25 MHz
75.84 MHz
75.96 MHz
Transmitter Proximities For Multiple
Channel Operation
Frequency groups being transmitted should
be separated by 2X the operating area;
and for best performance, the group
operating areas should have a 100 ft.
minimum separation.
transmitters
Group 2
operating area
transmitters
transmitters
Group 1
operating area
Group 3
operating area
Transmitter
separation
Transmitter
separation
72-76 MHz
STANDARD
COMPANDED CHANNELS
CHAN FREQ
72.02 MHz
72.04 MHz
72.06 MHz
72.08 MHz
72.10 MHz
72.12 MHz
72.14 MHz
72.16 MHz
72.18 MHz
72.20 MHz
72.22 MHz
72.24 MHz
72.26 MHz
72.28 MHz
72.30 MHz
72.32 MHz
72.34 MHz
72.36 MHz
72.38 MHz
72.40 MHz
72.42 MHz
72.46 MHz
72.50 MHz
72.54 MHz
72.58 MHz
72.62 MHz
72.64 MHz
72.66 MHz
72.68 MHz
72.70 MHz
72.72 MHz
72.74 MHz
72.76 MHz
72.78 MHz
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
CHAN FREQ
72.80 MHz
72.82 MHz
72.84 MHz
72.86 MHz
72.88 MHz
72.90 MHz
72.92 MHz
72.94 MHz
72.96 MHz
72.98 MHz
74.61 MHz
74.63 MHz
74.65 MHz
74.67 MHz
74.69 MHz
74.71 MHz
74.73 MHz
74.75 MHz
74.77 MHz
74.79 MHz
75.21 MHz
75.23 MHz
75.25 MHz
75.27 MHz
75.29 MHz
75.31 MHz
75.33 MHz
75.35 MHz
75.37 MHz
75.39 MHz
75.42MHz
75.46 MHz
75.50 MHz
75.54 MHz
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
CHAN FREQ
75.58 MHz
75.62 MHz
75.64 MHz
75.66 MHz
75.68 MHz
75.70 MHz
75.72 MHz
75.74 MHz
75.76 MHz
75.78 MHz
75.80 MHz
75.82 MHz
75.84 MHz
75.86 MHz
75.88 MHz
75.90 MHz
75.92 MHz
75.94 MHz
75.96 MHz
75.98 MHz
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
Recommended Channels For
Non-Companded Receivers
CHAN FREQENCY CHAN
05
15
23
30
40
67
74
84
50
60
72.1 MHz
72.3 MHz
72.5 MHz
72.7 MHz
72.9 MHz
75.5 MHz
75.7 MHz
75.9 MHz
74.7 MHz
75.3 MHz
A
B
C
D
E
F
G
H
I
J
Page 10
Optional Accessories
1. NBC 9-2C Battery charger
2. NBC 9-3-1 Digital fast charger
3. NBC 9-3-12 Digital 12-station fast charger
4. NH9-200 Rechargeable batteries
5. BC-216 Snap-on belt clip
(supplied with M-175)
6. P1 Universal pouch
7. SM-185 Unidirectional
electret condenser
microphone
8. PSC-HM Headworn
unidirectional electret
microphone
Auxiliary Audio Input Cords
9. CB-36 STM Stereo mini 3.5mm
(supplied with M-175)
10.
CB-36 RCA Phono plug
(optional)
11. CB-36 ST1/4 Stereo 1/4”
(optional)
12. CB-36 XLR XLR-F 3 pin connector
(optional)
M-175 OPTIONAL ACCESSORIES
Page 11
M-175 SPECIFICATIONS
Audio Input:
• Microphone input impedance for electret
type microphone - 3000 ohm
• Aux/Line input impedance - 10 k ohm
(0 dBV nominal)
Connectors:
Microphone - Micro-mini mono 2.5mm
Auxiliary - TRS 3.5mm jack
Audio: Tip and sleeve
Battery Charging: Tip and sleeve
Controls and Indicators:
• Synthesized channel selection switches
• Power On/Off switch
• Optional microphone switch
• Audio input gain control
• Power/Battery status indicator
• Audio (voice level) modulation indicator
• Manual compand switch
Frequency Response:
100 Hz to 10 kHz
Audio Distortion:
Less than 1% at 50% modulation
Modulation Limiter:
Soft compressor with 30 dB linear overload
protection; attack time - less than 1 ms,
recovery time - 10 ms
Frequency Modulation:
7.5 kHz deviation (companded)
5.0 kHz deviation (non-companded)
Operating Radio Frequency:
ity
:
88 synthesized channels in the 72-76 MHz
band.
Out-of-Band Emissions:
Better than 50 dB below carrier
R.F. Stability:
20 ppm XTL controlled
Digitally synthesized
RF Power Output:
40 mW to antenna system
FCC Compliance:
Type Accepted under FCC Part 90
Antenna System:
Body induction microphone cord
antenna.
Current Drain:
29 mA constant current
Battery:
• 9 volt alkaline Eveready 522
or equivalent for up to 16 hours
of use
• Rechargeable 9 volt Ni-MH
200 mAh battery for up to
5 hours of operation
•
Rechargeable 9 volt Lithium
Polymer
500 mAh battery
for up to 16 hours of use
Dimensions:
1 1
/16" x 2 1
/4" x 3 1
/2"
(27 mm x 57 mm x 89 mm)
Weight:
5 ounces (140 grams)
NOTE: Specifications subject to
change without notice or
obligation
Page 12
M-175 WARRANTY AND SERVICE
Warranty
COMTEK warrants this product to be free from defects in workmanship and
material under normal use and conditions for a period of one year from date
of original purchase. Items such as batteries, neckloops, and cords are not
covered by the warranty. Damage due to misuse, ill treatment and
unauthorized modification and repairs are not covered by this warranty. COMTEK is
not liable for consequential damages arising out of any failure
of the equipment to perform as intended. COMTEK shall bear no responsibility or
obligation with respect to the manner of use of any equipment sold by it.
COMTEK SPECIFICALLY DISCLAIMS AND NEGATES ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
OF SUCH EQUIPMENT INCLUDING, WITHOUT LIMITATION, ANY
WARRANTY THAT THE USE OF SUCH EQUIPMENT FOR ANY PURPOSE
WILL COMPLY WITH APPLICABLE LAWS AND REGULATIONS.
Service Policies
Warranty repairs must be done by COMTEK. Only factory technicians are
authorized to perform warranty service on the M-175 transmitter. Before
returning the M-175 for service, a Return Authorization Number should
be obtained from the service department by calling 1-800-496-3463 or
1-801-466-3463. Return the unit to the factory with the original or comparable packing.
COMTEK will pay for insurance and ground return shipping costs in the United States
for all warranty service.