ZETRON 37-MAX User manual

ZETRON
Model 37-MAX Repeater Pal
Installation Manual
Part No. 025- 376A
Please check for change information at the end of this manual.
Copyright © 1996 by Zetron, Inc.
ll Rights Reserved

WARRANTY STATEMENT
Zetron's warranty is published in the current Zetron United States Price Book.
DISCLAIMER
Zetron makes no representation with respect to the contents of this document and/or the
contents, performance, and function of any accompanying software and specifically disclaims
any warranties, expressed or implied, as to merchantability, fitness for purpose sold,
description, or quality.
Further, Zetron reserves the right to revise this document or the accompanying software and
to make changes in it from time to time without obligation to notify any person or
organi ation of such revisions or changes.
This document and any accompanying software are provided “as is.” Zetron shall not under
any circumstances be responsible for any indirect, special, incidental, or consequential
damages or losses to the buyer or any third party arising out of or connected with the buyer's
purchase and use of Zetron's products or services.
FEDERAL COMMUNICATIONS COMMISSION (FCC) REGULATIONS
To comply with FCC regulations, the following requirements must be met:
1. This device complies with Part 15 of the FCC rules for a Class A digital device.
Operation is subject to the following two conditions:
a. This device may not cause harmful interference.
b. This device must accept any interference received, including interference that
may cause undesired operation.
2. Repair work on this device must be done by Zetron, Inc. or a Zetron authori ed repair
station.
COPYRIGHT NOTICE
The software in this product is copyrighted by and remains the property of Zetron, Inc.
Reproduction, duplication, or disclosure is not permitted without prior written consent of
Zetron, Inc. No part of this document may be copied or reproduced in any form without the
prior written consent of Zetron, Inc.

TRADEMARKS
Ericsson/GE is a trademark of Ericsson GE Mobile Communications, Inc.
GE is a trademark of General Electric Company, USA.
Motorola is a trademark of Motorola, Inc.
Private-Line and PL are trademarks of Motorola, Inc.
ToneLock is a trademark of Zetron, Inc.
Touch-Tone is a registered trademark of American Telephone and Telegraph Company.
Zetron is a registered trademark of Zetron, Inc.
All other product names in this document are trademarks or registered trademarks of their
respective owners.

QUICK! — GET ME ON THE AIR!
If this is your first Model 37-MAX Repeater Pal, your first questions probably are “What do I
have to do to enable a tone?” and “Do I have to understand all the features just to make it
work?” Here are the answers:
Before you can work with the Model 37-MAX, it must be installed. FOLLOW THE
INSTALLATION INSTRUCTIONS (see Section 5). The installation should be accomplished
by a qualified radio service technician. Then get your transceiver (set on the repeater's
frequency and with touch-tone keypad) ready to enable some tones.
ACCESS THE PROGRAM MODE
To access the program mode, key up and press “12037”. A chirp should be heard coming
back from the repeater (the chirp, or five beeps, is the “go-ahead” prompt tone). If the
program mode is not accessed, check the Status LED on the front panel to see if it flashes
with every key pressed.
PROGRAM MODE PROMPT TONES
During programming, the Model 37-MAX will issue prompt tones to indicate how it’s doing.
A “warble” or “dee-doo dee-doo dee-doo” tone indicates an invalid command or that an error
condition exists. A “chirp” or “bip bip bip bip bip” (five quick notes) indicates the proper
completion of a command. A double “bip” indicates the panel is ready for additional digits to
be entered to complete a command. When exiting the program mode, a “ringing” sound will
be sent to verify the exit. If a key is not pressed within 60 seconds, the Model 37-MAX will
exit the program mode automatically.
ENABLE A CTCSS TONE
A CTCSS tone may be enabled by pressing “111# nn#”, where “nn#” is the tone number
from the User Numbers versus CTCSS Tones table in the Quick Reference section at the end
of this manual.
PROGRAMMING EXAMPLE
Enable CTCSS tones 67.0, 100.0, 127.3, and 186.2:
1. Access the program mode. Press “12037”, then listen for the five beeps.
2. Enable the tones.
for 67.0 H (tone 1), press 111# 1# (five beeps heard)
for 100.0 H (tone13), press 111# 13# (five beeps heard)
for 127.3 H (tone 20), press 111# 20# (five beeps heard)
for 186.2 H (tone 36), press 111# 36# (five beeps heard)
3. Exit the program mode. Press 99#, then listen for the ringing sound to verify exiting.
4. Test the repeater!

Table of Contents
1. INTRODUCTION .............................................................................................................. 1-1
OVERVIEW .............................................................................................................. 1-1
Complete CTCSS/DCS Coverage.................................................................. 1-1
Features You E pect in a Zetron Panel.......................................................... 1-1
Programming and Control.............................................................................. 1-2
Installation and Setup..................................................................................... 1-2
FEATURE SUMMARY............................................................................................ 1-3
USING THIS MANUAL ........................................................................................... 1-3
2. SPECIFICATIONS ............................................................................................................ 2-1
GENERAL SPECIFICATIONS ................................................................................ 2-1
RADIO INTERFACE SPECIFICATIONS................................................................ 2-1
ADDITIONAL SPECIFICATIONS .......................................................................... 2-1
PROGRAMMABLE FUNCTIONS........................................................................... 2-1
General........................................................................................................... 2-1
User Specific.................................................................................................. 2-2
Installation Aids ............................................................................................. 2-2
3. OPERATION ..................................................................................................................... 3-1
OVERVIEW .............................................................................................................. 3-1
USERS VERSUS CTCSS/DCS DECODE ............................................................... 3-1
USER OPERATION ISSUES ................................................................................... 3-2
Disabled Users ............................................................................................... 3-2
Enabled Users ................................................................................................ 3-2
Carrier Only Repeat ....................................................................................... 3-3
Reserved Users............................................................................................... 3-3
Tone Translation ............................................................................................ 3-4
NORMAL OPERATION........................................................................................... 3-4
Carrier is Detected ......................................................................................... 3-4
Valid Tone or Code is Detected..................................................................... 3-4
Repeater Hold Time....................................................................................... 3-5
Encode During Repeater Hold Time.............................................................. 3-5
Transmitting Morse Code Station ID............................................................. 3-5
Reserved Mode Users .................................................................................... 3-6
Courtesy Tone ................................................................................................ 3-6
SYSTEM OPERATION ISSUES.............................................................................. 3-6
Repeater Time-out Timer............................................................................... 3-7
DCS Polarity .................................................................................................. 3-7
Repeater Knock-down and Setup................................................................... 3-7

Table of Contents
(Continued)
4. PROGRAMMING ............................................................................................................. 4-1
OVERVIEW .............................................................................................................. 4-1
PROGRAM MODE ACCESS................................................................................... 4-1
Manually Resetting the Access Code............................................................. 4-1
ENTERING A PROGRAM COMMAND................................................................. 4-2
CLEARING PROGRAMMED SETTINGS .............................................................. 4-2
EXITING THE PROGRAM MODE ......................................................................... 4-2
USER PROGRAMMING COMMANDS ................................................................. 4-3
Enable and Disable a User ............................................................................. 4-3
Tone Translation ............................................................................................ 4-3
Tone-In-Tail ................................................................................................... 4-3
TX-Hold Time Selection................................................................................ 4-4
Reserved Mode .............................................................................................. 4-4
Courtesy Tone ................................................................................................ 4-4
SYSTEM PROGRAMMING COMMANDS............................................................ 4-4
TX-Hold Time Duration ................................................................................ 4-5
Repeater Time-out Timer (Stuck Mic)........................................................... 4-5
Station ID Parameters .................................................................................... 4-5
Station ID Call Sign ....................................................................................... 4-6
Courtesy Tone Frequency .............................................................................. 4-6
Program Mode Access Code.......................................................................... 4-7
DCS Encode Polarity ..................................................................................... 4-7
DCS Decode Polarity..................................................................................... 4-7
E it the Program Mode.................................................................................. 4-7
DIAGNOSTIC PROGRAMMING COMMANDS ................................................... 4-8
Repeater Knockdown and Setup.................................................................... 4-8
Reset Programming to Factory Default.......................................................... 4-8
TX Audio Test ............................................................................................... 4-8
TX Audio Pre-Emphasis Test ........................................................................ 4-8
Repeat Audio Test.......................................................................................... 4-9
CTCSS Encode Test ......................................................................................4-9
CTCSS Frequency Response Test ................................................................. 4-9
DCS Encode Test........................................................................................... 4-9
5. INSTALLATION ............................................................................................................... 5-1
INSTALLATION WARNING................................................................................... 5-1
GENERAL................................................................................................................. 5-1
EQUIPMENT REQUIRED FOR INSTALLATION................................................. 5-1
INSTALLATION PROCEDURE.............................................................................. 5-2
TESTS AND ADJUSTMENTS................................................................................. 5-3
ALTERNATE TEST AND ADJUSTMENT PROCEDURE.................................... 5-5

Table of Contents
(Continued)
RADIO SPECIFIC APPLICATION NOTES ............................................................ 5-7
Connection to a GE Master III Base/Repeater ............................................... 5-8
Connection to a GE Master II Base/Repeater ................................................ 5-9
Connection to a GE Custom MVP................................................................. 5-10
Connection to a GE EXEC II Base ................................................................ 5-11
Connection to a GE Master PRO ................................................................... 5-12
Connection to an EF Johnson Viking Universal Station ............................... 5-13
Connection to an EF Johnson CR1010 .......................................................... 5-14
Connection to an EF Johnson CR1010 (Alternate Hookup).......................... 5-15
Connection to an EF Johnson CR1000 .......................................................... 5-16
Connection to a Kenwood TKR720 / TKR820.............................................. 5-17
Connections to a Midland Basetech Repeater................................................ 5-18
Connections to a Motorola GR300/GR500 Repeater Station ........................ 5-19
Connections to a Motorola R100 Repeater Station........................................ 5-20
Connections to a Motorola MSF5000 Analog Base/Repeater....................... 5-21
Connections to a Motorola MSF5000 Digital Base/Repeater........................ 5-22
Connections to a Motorola MSR2000 Base/Repeater ................................... 5-23
Connections to a Motorola MICOR Base/Repeater....................................... 5-24
Connections to a Standard RPT10/RPT21..................................................... 5-25
Connections to a Standard RPT30 ................................................................. 5-26
Connections to a Tait T800 series Base/Repeater.......................................... 5-27
Connections to a Tait T300 series Base/Repeater.......................................... 5-28
Connections to a Uniden ARU-251 Repeater................................................ 5-29
Connections to a Uniden ARU-251K Repeater ............................................. 5-30
6. REPAIR ............................................................................................................................. 6-1
IN CASE OF DIFFICULTY ......................................................................................6-1
Service Notes ................................................................................................. 6-1
MODEL 37-MAX REPEATER PAL ASSEMBLY.................................................. 6-2
MODEL 37-MAX REPEATER PAL (702-9808A) .................................................. 6-3
Parts List ........................................................................................................ 6-3
Schematic....................................................................................................... 6-6
Silkscreen....................................................................................................... 6-9
APPENDIX A. PROGRAMMING LOG
QUICK REFERENCE
CUSTOMER FEEDBACK FORMS
CHANGE INFORMATION

1. INTRODUCTION .......................................................................................................1-1
OVERVIEW .......................................................................................................1-1
Complete CTCSS/DCS Coverage...........................................................1-1
Features You E pect in a Zetron Panel...................................................1-1
Programming and Control.......................................................................1-2
Installation and Setup..............................................................................1-2
FEATURE SUMMARY.....................................................................................1-2
USING THIS MANUAL ....................................................................................1-3

1-1
1. INTRODUCTION
OVERVIEW
The Zetron Model 37-MAX Repeater Pal is a high capacity, remotely programmable,
community repeater controller. It provides individualized repeater service to up to 154
different customer groups using CTCSS tone and Digital Coded Squelch (DCS) signaling.
The Repeater Pal connects to a receiver and transmitter providing CTCSS/DCS decode,
regenerated CTCSS/DCS encode, repeat audio processing, selectable system functions and
per-user functions. It will convert any station capable of full duple operation into a fully
featured community repeater. The Repeater Pal is an ideal replacement for older tone panels,
eliminating time consuming trips to remote repeater sites, as well as providing a high
subscriber capacity growth path for the future.
The compact size of the Repeater Pal is ideal for low power repeater packages constructed
from a pair of suitable mobile radios.
Complete CTCSS/DCS Coverage
The Repeater Pal has the capacity for supporting up to 154 separate user groups on a single
channel, which is ideal for scan based trunking systems, roaming, or seasonal users.
The panel is equipped with ToneLock decoding, an e clusive Zetron feature that eliminates
dropouts resulting from weak, fading signals or high modulation levels. The usable range of
the repeater is not limited by the decode performance of the repeater tone panel when the
Repeater Pal is in control.
The 37-MAX recognizes when a subscriber unkeys with a reverse burst, or the DCS turn-off
code, and silently mutes the repeat audio path to prevent bursts of “squelch tail” noise from
being repeated on the channel. The Repeater Pal also supports squelch tail elimination by
dropping its encode a short time before dropping its carrier when the station is unkeyed. This
ensures that listening radios mute without any annoying noise burst.
High quality audio processing circuits in the Repeater Pal are designed to make its repeater’s
audio quality rival the very best panels on the market.
Features You Expe t in a Zetron Panel
Aside from providing the decode and encode performance of a larger tone panel, the Model
37-MAX has many of the other features of the “big guys” as well.
The Morse code Station ID feature is fully field programmable. The ID call sign can be up to
eight characters in length. The panel can be set to wait for the ne t transmission to ID or to
ID automatically whenever the ID interval timer reaches zero. The duration of the ID interval
is also field programmable, as is the speed at which the ID is sent.

Section 1. Introduction
1-2
A Courtesy Beep, to inform listening mobiles that the speaker has definitely unkeyed, is
available on a per tone/code basis. The pitch of the Courtesy beep is also programmable (on a
system-wide basis) to either 500 Hz, 1000 Hz, or 1500 Hz.
The Reserved User feature helps to prevent the loss of tones or codes to co-channel operators
during periods when they are temporarily not in everyday use. When a tone or code is
programmed as ‘reserved’, the Repeater Pal will mute its repeat audio and transmit an alert
tone on the channel.
The Cross Tone encoding feature e pands the uses to which the panel can be put, allowing it
to support applications that require the panel to encode a different tone or code than it
received.
Programming and Control
In order to make it easy to install and easy to maintain, the Model 37-MAX is designed to be
programmed over the radio channel using any mobile or handheld capable of manual DTMF
encoding. If you wish to, you can use a Zetron Model 8B Repeater Programmer/Timekeeper
attached to a control station or mobile radio.
This programming method was chosen for two very good reasons. First, because it doesn’t
require the installer or maintenance technicians to have special equipment in order to
program the repeater; they can use equipment they already have. The second reason is that
you don’t have to be physically at the site in order to program the repeater. All the technician
needs to be able to do is to drive far enough into the repeater’s service area to be able to
reliably hit the repeater while programming it. This can pay real dividends when a trip to the
site is made difficult not just by distance but by accessibility as well.
Installation and Setup
Easy installation and setup procedures ensure that a technician can install a Model 37-MAX
in nearly any repeater or duple station. Only seven connections are required in typical
installations, and interfacing assistance is available from Zetron. Section 5 includes
application notes for some of the more popular repeaters, such as:
GE MASTER III, MASTER II, Custom MVP, EXEC II, MASTER PRO
EF Johnson Viking Universal Station, CR1010, CR1000
Kenwood TKR720, TKR820
Midland Basetech Repeater
Motorola GR300/GR500, R100, MSF5000, MSR2000, MICOR
Standard RPT10, RPT21, RPT30
Tait T800 series, T300 series
Uniden ARU-251
FEATURE SUMMARY

Section 1. Introduction
1-3
• Ma imum capacity of 50 CTCSS and 104 DCS user groups
• ToneLock high performance decoding
• Remotely programmable using DTMF radio
• Database and validation for 154 users
• Regenerated CTCSS/DCS and cross tone encode
• Vacant tones and codes can be reserved
• Selectable transmitter hold time and courtesy tone per user
• Programmable repeater time-out to deal with “stuck mic” problems
• Programmable Morse code station ID
• Repeat audio processing
• Proper operation with reverse burst and DCS turnoff code for squelch tail elimination
• Applications notes and connection diagrams available for popular radios
USING THIS MANUAL
While this manual was not written to be read from cover-to-cover, it is highly recommended
that you review Sections 3 and 5 before starting to work with the unit. Depending on your
level of e perience with Zetron’s other tone panels, you may want to review the Section 4 as
well. This manual contains the following sections:
1. INTRODUCTION Describes the Model 37-MAX, briefly lists its features and
describes this manual.
2. SPECIFICATIONS Lists the physical and electrical specifications of the Model 37-
MAX.
3. OPERATION Covers operation of the unit after it has been installed and the
levels set. The general basics of using the repeater are covered.
4. INSTALLATION Describes interfacing the Model 37-MAX to a generic station,
and has applications notes for a number of popular radios.

Section 1. Introduction
1-4
5. PROGRAMMING Provides background information on entering and e iting the
program mode. It also provides in depth e planations of the
programming commands and tables of tone frequencies and
DPL codes showing their relationship to user numbers.
6. REPAIR Contains low level hardware information such as parts lists,
schematics, and component layout silkscreens.
APPENDIX A Contains a programming log for recording the current system
and user programming.
QUICK REFERENCE Contains a list of all available programming commands.

2. SPECIFICATIONS .....................................................................................................2-1
GENERAL SPECIFICATIONS .........................................................................2-1
RADIO INTERFACE SPECIFICATIONS.........................................................2-1
ADDITIONAL SPECIFICATIONS ...................................................................2-1
PROGRAMMABLE FUNCTIONS....................................................................2-1
General....................................................................................................2-1
User Speci ic...........................................................................................2-2
Installation Aids ......................................................................................2-2

2-1
2. SPECIFICATIONS
GENERAL SPECIFICATIONS
Power 11 to 16 volts DC, 100 mA nominal
Operating Temperature 0° to 60° Celsius
Size 5.5 in W × 6.25 in D × 1.4 in H
Weight 1.0 pound
RADIO INTERFACE SPECIFICATIONS
Connections 12 volt DC, ground, RX Discriminator Audio, TX Mic Audio,
TX PTT, RX Carrier Detect, CTCSS/DCS Encode
PTT FET pull to ground
Carrier Detector External COR input with polarity and threshold adjustments
TX Audio -40 to +6 dBm, Hi/Lo range selector, 1 kΩ output impedance
RX Audio -40 to +10 dBm, Hi/Lo range selector, 25 kΩ input impedance
CTCSS/DCS encode -40 to +3 dBm, Hi/Lo range selector, 600 Ω output impedance
CTCSS slope Flat or de-emphasized output
ADDITIONAL SPECIFICATIONS
Indicators Status, Carrier, Transmit, Power
Station ID Morse Code, ixed 1200 Hz tone requency, and programmable
call sign
Programming Via DTMF radio
Data Retention Nonvolatile EEPROM
PROGRAMMABLE FUNCTIONS
General
Mode Carrier repeat, or validated CTCSS/DCS users
Station ID ID interval rom 1 to 90 minutes, call sign programmable up to
8 characters, periodic ID or ID based on transmit activity
TX Time-out 1 to 9 minutes in 1-minute steps
TX Hold Time 0 to 9 seconds in 1-second steps

Section 2. Specifications
2-2
Alternate TX Hold Time 0 to 9 seconds in 1-second steps
Courtesy Tone Frequency 500 Hz, 1000 Hz, 1500 Hz selectable
User Specific
Number o Users 155 database entries. User numbers are rom a cross-re erence
table based on CTCSS/DCS decode, 0 = Carrier repeat, 1 to 50
= CTCSS, 51 to 154 = DCS. Commands are available to
program a single user, or globally or all users.
User Status Disabled, enabled, or reserved. Reserved users will actuate the
transmitter and generate the proper CTCSS/DCS or dispatch,
but will not pass repeat audio. Valuable or no-pay customers.
Regenerated CTCSS/DCS Selectable encode may be any CTCSS or DCS, programmable
per user
TX Hold Time Normal or Alternate transmit hold time selection
Tone-in-Tail Enable or disable CTCSS/DCS encode during TX hold time
Courtesy Tone Enable or disable
Installati n Aids
DCS Polarity Programmable data inverters or encode and decode
Program Mode Access Five-digit DTMF password selectable
Clear Resets unit to all actory de ault settings
TX Audio Test Generates 1 kHz audio tone or transmit deviation adjustment
Repeat Audio Test Enables carrier repeat operation to adjust RX audio or unity
repeat gain
CTCSS Level Test Keys transmitter with CTCSS tone to check encode level
CTCSS Pre-emphasis Test Veri ies that CTCSS encode requency response is lat

3. OPERATION ..............................................................................................................3-1
OVERVIEW .......................................................................................................3-1
USERS VERSUS CTCSS/DCS DECODE ........................................................3-1
USER OPERATION ISSUES ............................................................................3-2
Disabled Users ........................................................................................3-2
Enabled Users .........................................................................................3-2
Carrier Only Re eat ................................................................................3-3
Reserved Users........................................................................................3-3
Tone Translation .....................................................................................3-4
NORMAL OPERATION....................................................................................3-4
Carrier is Detected ..................................................................................3-4
Valid Tone or Code is Detected..............................................................3-4
Re eater Hold Time................................................................................3-5
Encode During Re eater Hold Time.......................................................3-5
Transmitting Morse Code Station ID......................................................3-5
Reserved Mode Users .............................................................................3-6
Courtesy Tone .........................................................................................3-6
SYSTEM OPERATION ISSUES.......................................................................3-6
Re eater Time-out Timer........................................................................3-6
DCS Polarity ...........................................................................................3-7
Re eater Knock-down and Setu ............................................................3-7

3-1
3. OPERATION
OVERVIEW
This section ex lains the general o eration of the Re eater Pal on a to level, “big icture”
basis. The information resented here should be useful for evaluating a otential system
installation, as rimer before jum ing into the Programming section for the first time, and for
ex laining system functions to users on the system.
This section starts out by ex laining the relationshi between the very often used term "user
number" and the decoding of a articular CTCSS tone or DCS code. After discussing some
additional user issues related to setting u a valid tone or code, the normal actions of the
anel while in normal o eration are covered. The last ortion of this section covers the
o eration of system-wide timers and settings.
USERS VERSUS CTCSS/DCS DECODE
Since the Model 37-MAX is a multi-user re eater tone anel, it behaves as though it had a
se arate decode/encode module for each user grou it su orts. In reality, this is achieved
using a single micro rocessor controller and some very smart software to run it. The
advantages of this software a roach are:
• higher capacity than if we had built the anel using hardware modules. The Model 37-
MAX can decode and encode all 50 CTCSS tones and 104 of the DCS codes.
• flexibility of configuration at a level that would be difficult to rovide for even half as
many users if hysical switches or jum ers were required to configure user or system
attributes
• remote programming is as easy as (in fact, works the same as) local rogramming, which
means no more costly tri s to the site just to alter a single user or system arameter
In order to reduce the number of commands used in rogramming and to bring some order to
the rocess of setting u user grou s, the Model 37-MAX uses the conce t of a "user
number" to rogram features related to a s ecific CTCSS tone or DCS code. There is a fixed
relationshi between a user number and the tone or code to be decoded. The user numbers 1
through 50 are used for CTCSS tones (see Table 3. OPERATION -1) and the users numbers
51 through 154 are used for DCS codes (see Table 3. OPERATION -2). The user number "0"
is reserved for use with carrier squelch o erations. For exam le, in Table 3. OPERATION -
1, the user number 36 corres onds to the CTCSS tone frequency of 186.2 Hz. In Table 3.
OPERATION -2, the user number 55 corres onds to the DCS code "032". These re resent
the tone and code that would be decoded if these two user numbers were enabled. Table 3.
OPERATION -2 also shows an inverted code next to each of the rimary DCS codes.
Inverted codes are described in “DCS Polarity” later in this section.

Section 3. Operation
3-2
Table 3. OPERATION -1. ser Numbers versus CTCSS Tones
User
#
Tone
Motorola
Reed
Code
User
#
Tone
Motorola
Reed
Code
User
#
Tone
Motorola
Reed
Code
0 Carrier Repeat 1 114.8 2A 34 179.9 6B
1 67.0 XZ 18 118.8 2B 35 183.5 J5
2 69.4 WZ 19 123.0 3Z 36 186.2 7Z
3 71.9 XA 20 127.3 3A 3 189.9 J6
4 74.4 WA 21 131.8 3B 38 192.8 7A
5 77.0 XB 22 136.5 4Z 39 196.6 J7
6 79.7 WB 23 141.3 4A 40 199.5 J8
82.5 Z 24 146.2 4B 41 203.5 M1
8 85.4 A 25 151.4 5Z 42 206.5 8Z
9 88.5 B 26 156.7 5A 43 210.7 M2
10 91.5 ZZ 2 159.8 J1 44 218.1 M3
11 94.8 ZA 28 162.2 5B 45 225.7 M4
12 97.4 ZB 29 165.5 J2 46 229.1 9Z
13 100.0 1Z 30 167.9 6Z 4 233.6 M5
14 103.5 1A 31 171.3 J3 48 241.8 M6
15 107.2 1B 32 173.8 6A 49 250.3 M7
16 110.9 2Z 33 177.3 J4 50 254.1 J9
USER OPERATION ISSUES
A short list of to ics related to the setu and configuring of the users needs to be covered
before discussing normal tone anel o erations.
Disabled Users
The default condition for all users is disabled. The 37-MAX will still be able to decode these
tones and codes, but it will not react to them in any way. If a user has been reviously
enabled and rogrammed, the user can be disabled without altering any of that rogramming.
If the same user is enabled again at a later time, it will not need to be rogrammed again to
restore its o erational configuration.
Enabled Users
To lace a tone or code in service (or in the Reserved mode), the user number that
corres onds to the desired tone or code must be enabled. The other attributes and arameters
of a user's rogramming can be set or altered, even if that user is not currently enabled,
however, the user must be enabled for any of that rogramming to take effect.

Section 3. Operation
3-3
Table 3. OPERATION -2. ser Numbers versus DCS Codes
User
#
DCS
Code
Invert.
User
#
DCS
Code
Invert.
User
#
DCS
Code
Invert.
User
#
DCS
Code
Invert.
51 023 047 152 115 103 311 664 129 466 662
52 025 244 8 155 731 104 315 423 130 503 162
53 026 464 9 156 265 105 325 526 131 506 073
54 031 627 80 162 503 106 331 465 132 516 432
55 032 051 81 165 251 10 332 455 133 523 246
56 036 172 82 172 036 108 343 532 134 526 325
5 043 445 83 174 074 109 346 612 135 532 343
58 047 023 84 205 263 110 351 243 136 546 132
59 051 032 85 212 356 111 356 212 13 565 703
60 053 452 86 223 134 112 364 131 138 606 631
61 054 413 8 225 122 113 365 125 139 612 346
62 065 271 88 226 411 114 371 734 140 624 632
63 071 306 89 243 351 115 411 226 141 627 031
64 072 245 90 244 025 116 412 143 142 631 606
65 073 506 91 245 072 11 413 054 143 632 624
66 074 174 92 246 523 118 423 315 144 654 743
6 114 712 93 251 165 119 431 723 145 662 466
68 115 152 94 252 426 120 432 516 146 664 311
69 116 754 95 255 446 121 445 043 14 703 565
0 122 225 96 261 732 122 446 255 148 712 114
1 125 365 9 263 205 123 452 053 149 723 431
2 131 364 98 265 156 124 454 266 150 731 155
3 132 546 99 266 454 125 455 332 151 732 261
4 134 223 100 271 065 126 462 252 152 734 371
5 143 412 101 274 145 12 464 026 153 743 654
6 145 274 102 306 071 128 465 331 154 754 116
Carrier Only Repeat
While the whole oint of a "tone anel" is to control re eater o eration based on the tone or
code being decoded, the Model 37-MAX can also be rogrammed to re eat on just carrier
(sometimes called "carrier controlled re eat", "carrier squelch", or an "o en re eater"). When
this mode of o eration is enabled, the 37-MAX will allow any user to bring u the re eater,
regardless of any encode. Users with CTCSS or DCS encode will be treated as the Carrier
Re eat user if this mode is enabled.
The user number "0" has been designated as the Carrier Re eat user. This allows all of the
standard user- rogrammable features for carrier re eat, such as enable/disable, CTCSS or
DCS encoding, reserve mode.
Reserved Users
There will be times when a tone or code sto s being used on a regular basis, due to the nature
of how the user grou assigned to it does business. This idleness laces that tone or code at

Section 3. Operation
3-4
risk of being taken over by another local co-channel re eater system in a busy market,
rendering it unavailable whenever the original user wants to resume using "their tone".
To hel revent this roblem, the 37-MAX rovides a feature called the Reserve mode.
When an ENABLED user is laced in this mode, the anel will still key u on decoding that
tone or code, but it will not ass audio. Instead, the 37-MAX will transmit a bee tone to
indicate to anyone monitoring the channel that a reserved tone is in use. The anel will still
encode the ro er CTCSS tone or DCS code for this user.
Disabling a user number will revent that user from o erating in Reserve mode. Tem orary
or seasonal users that the system o erator lans to use in the future should always be
reserved, not sim ly disabled, whenever they enter a eriod of idleness.
Tone Translation
The fixed relationshi in the Model 37-MAX is between the user number and the CTCSS
tone or DCS code that is decoded. The default is for the anel to encode the same tone or
code that is decoded for a user, however, this relationshi can be altered in rogramming.
Each user may be rogrammed to encode any CTCSS tone or DCS code, or to not encode at
all.
NORMAL OPERATION
The items in this subsection cover how the anel behaves while o erating in its normal mode.
The actions of the Model 37-MAX will be determined by both which features have been
enabled in rogramming and what signals are coming to it from the receiver.
Carrier is Detected
Whenever the 37-MAX receives a carrier detect signal from the receive radio, it will first
check to see if the anel is rogrammed for Carrier Re eat o eration (user number "0" is
enabled). If Carrier Re eat is enabled, then the 37-MAX will key the transmitter and unmute
the re eat audio ath. If an encode tone or code has been rogrammed for the "0" user
number, it will be encoded. If the Carrier Re eat function has not been enabled, then the
Re eater Pal will not take any actions until it checks for decode of a CTCSS tone or a DCS
code.
Valid Tone or Code is Detected
After res onding to the carrier detect signal from the receiver and determining that it is not
enabled to do Carrier Re eat, the Model 37-MAX will start its decode software routines to
determine if there is a CTCSS tone or DCS code in the receive signal. Once the anel
determines which tone or code is resent, it looks in its user database to see if that tone or
code is enabled. If the tone or code is not enabled the anel ignores it. If the tone or code is
enabled, the anel checks whether or not it is Reserved. If the Reserved mode is not enabled
for that user, then the 37-MAX will key the transmitter, start encoding the rogrammed tone
or code for that user, and unmute the re eat audio ath. The 37-MAX will remain in this