CES 600L User manual

Model 600L
DTMF Microphone
Master OEM Manual
01100119 REV G
December 4, 1995
MAN03

Limited Warranty
CES Wireless Technologies (CES) warrants it's products to be free of defects in
material and workmanship and extends this warranty under intended use and normal
service conditions to the original owner for a period of one year from the date of
purchase.
This warranty does not apply to any product that has been subjected to repairs or
alteration not authorized by CES, or for any product that has been damaged due to
accident, abuse, neglect, vandalism, loss, unreasonable use, improper installations,
lightning, fire, or water damage.
The obligations of CES are limited to repairing or replacing, at the option of CES, any
product or component that is returned to the factory all transportation charges prepaid,
accompanied by proof of purchase and which examination reveals to have been
defective within the warranty period stated above. CES does not assume, nor is any
person authorized to assume for it, any obligation other than that stated herein.
Any implied warranties, including but not limited to fitness for a particular purpose, are
limited in duration for the above one year period. CES shall not be liable under this
warranty, or any implied warranty, for the loss of use of the product or for any other
consequential loss or damage incurred by the purchaser.
Some states do not allow the exclusion or limitation of implied warranties or
consequential damages and so the above exclusions or limitations may not apply. This
warranty gives you special legal rights and you may have other rights that vary from
state to state.
* * * * * * * * * * * * * * * * * * * * * * *
CES takes pride in the products and after the sale support that we offer our many
customers.
Copyright 1995 by CES, Winter Park, Florida. All rights reserved. Due to continual
product improvements, descriptions and specifications are subject to change without
notice.
file: 600L-uni.man

Model 600L Universal Microphone Manual
GENERAL DESCRIPTION
The CES Model 600L DTMF Encoder Microphone is engineered specifically for use
with a wide variety of mobile radio applications. Whether used on SMR trunked
systems, conventional telephone interconnected shared mobile radio systems, or in
dedicated single-user radio systems, your new 600L microphone will enhance the utility
of your mobile communications. Standard features in the Model 600L microphone
include:
nn Automatic push-to-talk transmitter keying
nn Direct compatability with many models of mobile radio products
nn Installed mating connector available for many popular model radios
nn Durable backlighted silicone rubber keypad
nn Precise crystal controlled tone generation
nn Automatic microphone muting
nn Audible DTMF sidetone to ensure proper dialing
nn Rugged urethane extreme temperature coil cord
nn Optional fixed length DTMF digit dialing (150 milliseconds)
Page 1

INSTALLATION
Your CES Model 600L DTMF Encoder microphone may be easily configured for the
particular application. Power is supplied to the microphone through the radio's
microphone connector for all functions, including: audible sidetone and keypad
illumination.
If the Model 600L microphone was ordered for a specific application, a mating
connector is installed; or, an appropriate connector may be installed using the
information supplied below:
Cable Wire
Color Function
BLUE +12 VDC Input
RED Push-To-Talk (logic low)
WHITE TX Audio Output
BLACK CTCSS Hang Up (logic low)
SHIELD Audio/Logic Ground
YELLOW Logic and Power Ground
CTCSS Hang Up (Monitor) is a logical function that will normally (as shipped) provide
an off-hook (open-circuit) to the radio for CTCSS or DCS squelch "monitor" , or other
decoder functions, and a logic low when placed on-hook. A grounded microphone
hang-up clip is required.
A CTCSS Inverter is available as a factory option that provides reversed logic from the
method described above. That is: the CTCSS Hang Up logic is an open-circuit when
on-hook, and a closed circuit (logic low) when taken off hook.
Page 2

LEVEL SETTING AND INTERFACE ADJUSTMENTS
To accomplish level setting and any changes in (jumper) options, remove the four
screws and the microphone back cover.
Jumper JP1 - Audio Gain Select Jumper
This jumper is used to set the range of microphone and DTMF audio output from the
600L microphone. When JP1 is installed (factory default, as shipped), it will
accommodate requirements where the microphone audio is in the range of 40 mV or
less. For higher voice and DTMF tone input levels, remove JP1.
DTMF Tone Output Level (RV1)
For reliable DTMF signaling: The DTMF tone deviation should be approximately 2/3 of
the maximum deviation (for example: if the modulation limiting is set to 5.0 kHz, then
the DTMF level should be 3.3 kHz). In any event, the DTMF Tone transmitted by the
600L microphone should not be clipped or distorted. If your service monitor does not
have a CRT display to observe the transmitted waveform, use an oscilloscope
connected to the "demod" output from the service monitor to visually verify the quality
of this signal. Set RV1 for the proper DTMF Tone level (3.3 kHz). For applications
where a 2.5 kHz deviation limit is used, set the DTMF level to approximately 1.7 kHz
with no CTCSS tone, or 2.2 kHz with CTCSS tone. If the output is insufficient for
proper modulation deviation, then remove JP1.
Voice Level Adjustment (RV2)
This adjustment sets the microphone level for voice modulation only. While monitoring
the transmitter frequency on a service monitor, press the microphone PTT switch and
set RV2 on the 600L microphone so that the voice deviation peaks just before limiting
(clipping) occurs while speaking in an average voice level. Remove JP1 if the proper
modulation level cannot be reached.
Tone Burst Mode
The 600L microphone is shipped for the continuous DTMF tone mode. This mode
provides a DTMF tone for the duration that the user presses a key. For the Burst Mode
option, where a fixed length DTMF tone burst of 150 milliseconds is desired, install
jumper JP4 (shown on figure "A").
Automatic Push-To-Talk (PTT)
The 600L microphone is shipped with Automatic Push-To-Talk enabled, where PTT
occurs upon depressing any keypad digit. Should the application require that the user
press the PTT switch in order to encode DTMF dialing, then remove resistor R2 (10K)
to invoke this operation, and disabling the Automatic PTT feature. See Figure "A" for
the location of R2. If R2 is removed, sidetone audio will not be heard from the
microphone during DTMF dialing. Page 3

LEVEL SETTING AND INTERFACE ADJUSTMENTS - continued
Adjusting DTMF Twist
The DTMF microphone generates two tones when any keypad button is pressed. The
following table illustrates the row tones and column tones generated by activating a
keypad button: Column Tones (Hz)
1209 1336 1477
Row 697 1 2 3
Tones 770 4 5 6
(Hz) 852 7 8 9
941 *0 #
The term "DTMF Twist" is the ratio between the level of the column tone and the row
tone generated by any keypad button. In application, the higher frequency (column)
tones are more readily attenuated than the lower frequency (row) tones, the high
frequency tones of any DTMF are generated by the microphone at a slightly higher
level.
The 600L microphone is shipped with the proper DTMF twist required for most
applications, and this procedure should not be necessary.
Should a particular application require the DTMF twist to be tested or changed, the
following may be accomplished: (the temporary modification allows two keypad digits
to be pressed within a column or row - resulting in the generation of a single tone
applicable to that column or row):
(1) Cut the plating run on the bottom of the 600L printed circuit board at JP6.
(2) If installed, remove 600L microphone jumper JP4 (disables Burst Mode operation).
(3) Press two keys within a column (for high tones) or two keys within a row (for low
tones) while monitoring the transmitted tone level on a service monitor.
Page 4

LEVEL SETTING AND INTERFACE ADJUSTMENTS - continued
(4) The ratio of high to low tones may be modified by changing the value of C9 (470 pf):
Increase the value to reduce the DTMF twist ratio
Decrease the value to increase the DTMF twist ratio
Table of Single-Tone Encoding - Service Mode
Keypad
Location Reference Tone (Hz) Actual Tone Output (Hz) Percent Deviation
Row Tone 1 697 699.1 +0.30
Row Tone 2 770 766.2 -0.49
Row Tone 3 852 847.4 -0.54
Row Tone 4 941 948.0 +0.74
Column Tone 1 1209 1331.7 +0.57
Column Tone 2 1336 1331.7 -0.32
Column Tone 3 1477 1471.9 -0.35
(5) Reinstall JP6 with a wire jumper, returning the microphone to normal operation.
Isolating Analog, Logic, and Power Grounds
If your application requires that the microphone audio, push-to-talk logic, and -12 VDC
grounds be separate: Cut the jumper JP2 on the printed circuit board as shown in
Figure "A".
PTT Logic associated with Microphone Audio
If your application requires that the push-to-talk logical low signal be on the microphone
audio line: Then install a wire jumper or resistor, as required by the application, at JP3.
CTCSS Monitor (Standard Communications GX series)
For the Standard Communications GX series mobile radios: Install a 10K ohm 1/8 watt
resistor at R6. If you ordered the 600L microphone for this application, this (GXC)
option has already been installed.
Page 5

CTCSS Monitor (Inverted Logic)
For applications where the CTCSS monitor hookswitch circuit is open-circuit when the
microphone is on-hook, and closed-circuit when off hook (Ericsson-GE and others):
Remove R11
Install R20 (27K ohm)
Install R22 (27K ohm)
Install C17 (.001 uf)
Install Q3 (MPS2222)
If you ordered the 600L with this specification, this option has already been installed.
If an operating voltage (+8 to +12 VDC) not already available at microphone connector,
locate a spare or unused pin on the radio microphone connector. Some radio
microphone connectors may not have any obvious "spare" pins, but an existing function
such as speaker or handset receive audio may be disconnected to free up the pin.
Make a wire connection from this pin to a switched voltage within the radio (+8 to 12
VDC), and one that is filtered and/or regulated. Connect the microphone cable Blue
wire to this source voltage connector pin on the microphone connector plug.
If the radio application has no provision for providing the necessary operating voltage
for the microphone and the radio microphone audio circuit incorporates a bias voltage of
approximately 7 volts or more, a special version of the 600L is available from CES to
interface with this requirement. Contact your CES Sales Representative for more
information.
Page 6

THEORY OF OPERATION
Power to the microphone is provided via the radio microphone connector. This +12
VDC source voltage is filtered by C3 and regulated to 5.0 volts by VR1.
Each time a key is pressed on the keypad, the normally low output of U2 pin 8 goes
high, forward biasing CR2 and causing C2 to charge. The rise in voltage on inputs of
U1C pins 8 and 9 causes the output pin 10 to go low. A low on either U1A pin 1 or U1B
pin 6 results in the output of U1A-3 and U1B-4 to latch to a high state. The high input
on the gate of Q1 in the drain output going to a low state and asserting a push-to-talk
output to the radio. The charge on C1 will keep PTT low for approximately 1.5 seconds
after each key is pressed. This delay allows for an adequate period of time for another
user-initiated key to be subsequently pressed before transmitter push-to-talk is allowed
to return to the unkeyed mode.
With jumper JP4 in-place, the DTMF tone generated will be a tone burst of
approximately 150 ms per digit, irregardless of how long the key is pressed. As
received from the factory, the jumper is removed and each DTMF tone is generated for
the entire duration of a pressed key.
If the Burst Mode is enabled (JP4 installed), the length of the DTMF tone burst may be
changed to accommodate a particular system requirement: Change R18 (270K) to a
higher value to increase, or to a lower value to decrease the time period for each DTMF
tone.
If the automatic push-to-talk feature is disabled by removal of resistor R2, the
microphone will have to be manually keyed (PTT depressed) to send the DTMF tones.
In this mode, when the PTT switch is depressed, an active high is placed on the gate of
Q1 causing the PTT output to go low enabling the transmitter and permitting the DTMF
tones to be transmitted.
The DTMF tone output is generated at U2 pin 16, and the DTMF output level is set with
RV1. The microphone element voice output is amplified by U3A, where the gain and
voice level is set by RV2 and then combined with the previously set DTMF audio level.
Both voice and DTMF tones are further amplified by U3B (the actual gain determined
by jumper JP1 setting: JP1 installed = low output, JP1 out = high output). The
combined DTMF tones and voice audio are coupled through a non-polarized capacitor
C11 to the microphone high input to the radio.
The DTMF tones are connected to the microphone element EM1 when the PTT button
is not depressed to provide audible sidetone of dialed digits. Sidetone is disabled if
resistor R2 is removed for the Manual PTT option.
Page 7

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Model 600L Universal Microphone Parts List
Symbol
Number Description CES Part Number Symbol Number Description CES Part Number
C1,8,19
C2,6,16
C3
C4
C5
C7,12,18
C9
C10
C11
C13,14,15
CR1,3
CR2,4
EM1
Q1
Q2
Q3
R1
R2,6
R3
R4
R5,13
R7,14,23
R8,9
R10
R11,19,21
R12
R15
R16,17
R18
R20,22
RV1
RV2
.1 uf 35V Capacitor
10 uf 16VTant. Capacitor
10 uf 25VTant. Capacitor
1500pf Capacitor
.01 uf Capacitor
1 uf Capacitor
470 pf Capacitor
22 pf Capacitor
2.2 uf 16V NP Capacitor
220 pf Capacitor
1N5248Zener Diode
1N914 Diode
Microphone Element
N CH Mosfet VN10KM
NPN Transistor MPSA06
MPS2222 Transistor
200K 1/8W Resistor
10K 1/8W Resistor
100 1/8W Resistor
1K 1/8W Resistor
4.7K 1/8W Resistor
150K 1/8W Resistor
82K 1/8W Resistor
680 1/8W Resistor
0 1/8W Resistor
8.2K 1/8W Resistor
470 1/8W Resistor
100K 1/8W Resistor
270K 1/8W Resistor
27K 1/8W Resistor
100K Potentiometer
10K Potentiometer
CM.1
CT10
CT106
CM1501
CM.01
CT1
CM471
CC22P
CT2.2NP
CM221
D5248
D914
MIC01-K
QVN10
QA06
Q2222A
RC204
RC10K
RC101
RC103
RC472
RC154
RC823
RC681
RC-JUMPER
RC8.2K
RC471
RC104
RC274
RC273
RV100K
RV103
P1
P2
SW1
U1
U2
U3
VR1
Y1
NON-
REF
ITEMS
Connector, 6 Pole
Flex Strip, 9-circuit
PTT Switch DPDT
IC CMOS CD4011
IC DTMF Encoder
IC TL062
IC Regulator 78L05
3.579Mhz Crystal
Front Case Half
(includes DTMF keypad)
Rear Case Half
Hang-up Button
Ground wire w/terminal
Felt Screen
Metal Screen
PTT Lever, Plastic
Rubber Ring
Neoprene Pad
Case Screw #4 x 5/16"
Microphone Cord
Strain Relief
Rubber Boot
Complete Case Assembly
Rear Label: 600LUniv
CON54
FLEX1
MIC01-M
U4011
U2559
U062
U78L05
XTAL3
MIC01-A
MIC01-B
MIC01-C
MIC01-D
MIC01-E
MIC01-F
MIC01-G
MIC01-H
PAD03
SCREW40
CRDCES-1
STRNREL04
BOOT1
600LMF
LABEL002