- CONTROL HEADS & ACCESSORIES
		- Control Head Configuration
		- Clamshell Mode Select Control Heads
			- 1 to 16 Modes Photo
			- 32 Mode Photo
			- 16 Mode Talkaround Photo
		- System 90*s Housings
			- HHN4008A Rear Photo
			- HHN4009A Rear Photo
			- HHN4010A Rear Photo
		- System 90*s Mode Select Control Heads
			- 1 Mode / 8 Mode Bank Select Photo
			- 16 Mode Bank Select Photo
			- 32 Mode Bank Select Photo
			- 2 Mode Select Photo
			- 8 / 16 / 32 Mode Select Photo
			- 8 / 16 / 32 Mode Select + Scan Photo
		- System 90*s Operator Select Non-Priority Scan Modules
			- 8 Mode Operator Select Non-Priority Scan Photo
		- System 90*s Operator Select Multiple PL/DPL Modules (MPL)
			- 8 Code Operator Select MPL Photo
		- System 90*s and System 90 Optional Equipment
			- HLN4026A Touch Code Decoder Photo
			- Touch Code Decoder Circuit Board Photo
			- HLN1077A MDC-600 Selective Call Decoder Photo
			- MDC-600 Selective Call Decoder Circuit Board Photo
		- HHCH Control Head and Accessories
		- PAC-RT and PAC-PL Vehicle Repeater
		- Syntor X Accessories
		- Internal Options for the Syntor X
		- Special Syntor X Parts
		- Control Head Diodes
	- Syntor X Home
	- HOME

Control head configuration:

This page has information about clamshell, System 90, System 90*s and HHCH control heads, accessories and internal options. Please be sure to check the clamshell control head or System 90*s control head basic configuration information as incorrectly configured control heads are a frequent problem. To determine if you need to use Mode Strobe check the board number of any System 90*s boards hooked up to the radio cable. Look up the boards on this page and if you find one listed with a ** then you need to use Mode Strobe.

Clamshell mode select control heads:

HCN1009A* - Control Head, 8 Mode
HCN1019A - Control Head, 16 Mode, photo
HCN1020A - Control Head, 32 Mode, photo
HCN1022A - Control Head, 16 Mode with Talk-Around, photo
HCN1023A - Control Head, 8 Mode with Talk-Around
* - this 8 mode clamshell is also a Syntor part and is lacking some internal diodes the other Syntor X clamshell control heads use. It works just fine when it is used by itself and the radio is setup properly.

• Here is how to check the basic configuration of your clamshell control head.
  • When the clamshell control head is used all by itself, the mode select rotary switch common terminal is internally wired to the 22 pin black connector pin 21 (ground). This is also true when the clamshell is combined with accessories that do not use the radio's mode lines (i.e. there are no other boards connected to the cable that supply the Mode Strobe signal).
  • When the clamshell control head is used with System 90*s accessories that use the radio's mode lines, the mode select rotary switch common terminal is internally wired to the 22 pin black connector pin 5 (Mode Strobe).
  • For normal non-DVP operation, audio is supplied through the 22 pin black connector pin 16 (Detected Audio), the 22 pin blue connector pin 16 (DVP Audio) is not connected and resistor R1103 (3.3 K ohm) is present.
  • DVP compatible control heads remove resistor R1103 (3.3 K ohm) and supplies the receiver audio through the 22 pin blue connector pin 16 (DVP Audio).
  • See the radio service manual for details.
• The HCN1022A 16 mode with Talkaround clamshell control head and the HCN1020A 32 mode clamshell control head are both 32 mode control heads. The only difference is the HCN1022A has a bank select switch marked "R - D" and the HCN1020A has a bank select switch marked "A - B".
• The HCN1023A 8 mode with Talkaround clamshell control head and the HCN1019A 16 mode clamshell control head are both 16 mode control heads. The only difference is the HCN1023A has a bank select switch marked "R - D" and the HCN1019A has a bank select switch marked "A - B".

System 90*s housings:

There are several slightly different housings for System 90*s boards. The difference is the rear panel connector configuration. Most of the time the System 90 or System 90*s part number found on a small white label on the printed circuit board is the only identification (not to be confused the housing part number, see below). The DVP housing is a special housing designed to accommodate a round keyloader connector on the front of the housing.

There is a standard configuration used for the board that controls the power on/off, volume, squelch and selects the mode banks. The microphone and speaker are also connected to this board. There is a 22 pin connector on the left side and a 6 pin, 2 pin, and 6 pin connectors on the right side (as viewed from the rear of the housing). I will refer to this as the "STD" configuration.

There is a configuration with two 22 pin connectors, one on the right and the other on the left. I will refer to this as the "OPT" configuration.

Each housing has positions for two boards, one on top and the other on the bottom. Each one of these boards has its own connector configuration.

HHN4008A - Black System 90*s Housing, back photo (top position - OPT, bottom position - STD)
HHN4009A - Black System 90*s Housing, back photo (top position - OPT, bottom position - OPT)
HHN4010A - Black System 90*s Housing, back photo (top position - STD, bottom position - STD)

HHN4011A - Black System 90*s Housing for Securenet (DVP)

Often one of the above four part numbers is the only one found on the outside of a System 90*s housing and therefore is incorrectly mistaken as the part number for the entire assembly including the boards inside the housing.

HLN4235A - Public Address or Siren System 90*s housing back plate.

System 90*s mode select control heads:

Below is a combination of complete control heads and the printed circuit boards that go into the complete control head. To help sort things out the part numbers for the circuit boards are underlined. The "used with" notes in parenthesis are information I added. The circuit board numbers are the ones mostly encountered in the field. Kit numbers are usually only found on factory shipping containers and and are used when ordering new parts from Motorola. Most of the time the circuit board part number is found on a small white label on the printed circuit board is the only identification (sometimes the part number is printed directly on the board). The information in the curly braces is the manual code. Use it to find the manual that covers the board.

Motorola considers the clamshell (rotary) control heads to be the "standard" Syntor X control heads. The following list is System 90*s "alternate" (pushbutton) control mode selection modules:

HLN1062A - 8 Mode Pushbutton Select Module
HLN1061A - 8 Mode Pushbutton Select Module with Scan for 8 Mode Control Head
HLN1075A - 8 Mode Pushbutton Select Module with Scan for 16 or 32 Mode Control Head
HLN1063A - Alternate Control Module, 8 Mode, photo
HLN1065A - Alternate Control Module, 16 Mode, photo
HLN1066A - Alternate Control Module, 32 Mode, photo

• A complete pushbutton control unit also requires the following components: first select one of the three 8 Mode Pushbutton Select Modules, second select one of the three alternate control modules, then add the HHN4008A (housing) and HLN4208A (single housing trunnion).
• The above part numbers were used for ordering and if you find any new in the box System 90*s control heads you may run into these part numbers. I have no information on which circuit boards were provided with these order numbers (see below).

TRN4395A - Bank Select or 1 Mode Select, Volume, Squelch board {S9s-1}
TCN1352A - Bank Select or 1 Mode Select, Volume, Squelch Kit w/ TRN4395A , Hardware & Escutcheon, photo
TRN4340A - A, B Bank Select or 2 Mode Select, Volume, Squelch board {S9s-1}
TCN1351A - A, B Bank Select or 2 Mode Select, Volume, Squelch Kit w/ TRN4390A , Hardware & Escutcheon, photo
TCN1350A - R, D Talkaround Bank Select, Volume, Squelch Kit w/ TRN4340A , Hardware & Escutcheon
HLN4296A - A, B Bank Select, Volume, Squelch board (use with TRN4344 or HLN4336) {S9s-1}
TCN2265A - A, B Bank Select, Volume, Squelch Kit w/ HLN4296A , Hardware & Escutcheon, photo
HLN4298A - A, B, C, D Bank Select, Volume, Squelch board (use with TRN4344 or HLN4336) {S9s-1}
TCN2266A - A, B, C, D Bank Select, Volume, Squelch Kit w/ HLN4298A , Hardware & Escutcheon, photo
TRN4343A - 5 Mode Select board (non-scanning) {S9s-1} **
TCN2267A - 5 Mode Select Kit (non-scanning) w/ TRN4343A , Hardware & Escutcheon
TRN4344A - 8 Mode Select board (non-scanning) {S9s-1} **
TCN2268A - 8 Mode Select Kit (non-scanning) w/ TRN4344A , Hardware & Escutcheon, photo
TRN4330A - 2 Mode Select with Scan and Indicators board {S9s-2} **
TLN2258A - 2 Mode Select with Scan and Indicators Kit w/ TRN4330A , Hardware & Escutcheon
TRN4334A - 5 Mode Select with Scan and Indicators board {S9s-2} **
TLN2260A - 5 Mode Select with Scan and Indicators Kit w/ TRN4334A , Hardware & Escutcheon
TRN4338A - 8 Mode Select with Scan and Indicators board {S9s-2} **
TLN2262A - 8 Mode Select with Scan and Indicators Kit w/ TRN4338A , Hardware & Escutcheon, photo
TLN1061A - 8 Mode Select with Scan and Indicators Kit w/ TRN4338A , Hardware & Escutcheon, photo
HLN4336A - 16/32 Mode Select with Scan and Display board (use with HLN4296 or HLN4298) {S9s-2} **
TLN1075A - 16/32 Mode Select with Scan and Display Kit w/ HLN4336A , Hardware & Escutcheon, photo

• Here is how to check the basic configuration of your System 90*s control head bank select board.
  • When a bank select board is used without a mode select board (1 and 2 mode control heads) and there are no other System 90*s accessories that supply the Mode Strobe signal, the 6 pin blue connector pin 4 (Mode Strobe In) is connected to ground.
  • If any boards are present that supply the Mode Strobe signal then the 6 pin blue connector pin 4 (Mode Strobe In) is connected to Mode Strobe (if it is used at all).
  • For normal non-DVP operation, audio is supplied through the 22 pin black connector pin 16 (Detected Audio), the 6 pin blue connector pin 5 (DVP Audio) is not connected and resistor R4 (3.3 K ohm) is present.
  • DVP compatible bank select boards remove resistor R4 (3.3 K ohm), supplies the receiver audio through the 6 pin blue connector pin 5 (DVP Audio) and jumper JU8 is installed.
  • See the S9s-1 manual for details.
• ** - These boards supply the Mode Strobe signal.
• Normally, a Bank Select board is combined with Mode Select board and placed in a HHN4008A housing. Combined they make up the Mode Select control head. Bank select boards can be used without a mode select board. This is done for 1 and 2 mode control heads that do not have scan or indicators.
• The HLN4336A 16/32 Mode Select with Scan and Display actually has 8 Mode Pushbuttons. All of the other Mode Select boards with Scan and Indicators are only designed to show one specific bank (A/B/C/D) of 8 modes (jumper selected). The 16/32 Mode Select board shows any scan activity in banks A, B, C or D (i.e. if the mode 5 light lights up while scanning, it could mean mode 5 bank A, bank B, bank C or bank D is actually active). This difference appears to be the reason this board is the only one listed with a Display, instead of Indicators. The TRN4338A can mimic this multiple bank scan display when jumper JU11 (orange wire) is moved to the JU7 position A, but it lacks protection from the false mode 32 display problem.
• "Display" or "Indicators" means the radio directly controls the boards Mode and/or PRI lights. Otherwise these lights are directly wired to the board's switches and are not accessible to the radio. So just because "indicators" or "display" is not mentioned does not mean the board has no display lights, it means it has no display lights the radio directly controls. The method used by the radio to control the lights is unique to Syntor X radios and therefore so are the boards with "indicators" or "display".
• Unlike earlier Motorola radio lines the Syntor X radio has an internal microprocessor that does the scanning. Older radio lines needed external hardware to make the radio scan. Avoid the scan control heads from older radio lines (i.e. Syntor, Mitrek, Micor, etc.).
• For mode select boards with "Scan", all "Scan" really means is the board has a switch (labeled PRI) to ground J1-31 Channel Scan Enable to activate the radios built in scanning.
• False mode 32 display: for 32 mode selection control heads with scan, the HLN4336A and HLN4298A boards should be used together. The radio sends a false mode 32 display to blank the display (used by 16 mode or fewer control heads) and these two boards have additional hardware to filter out this false mode 32 display. There are extra connections that must me made between the control head and radio for these boards (PTT and Squelch Tail). Other boards (i.e. TRN4338A) can be made to display all 32 modes, but the mode 8 light will light up when it should not because of the false mode 32 display. The 2 bank select (A/B) HLN4296A also has the hardware for the PTT output connection and it can be used if you convert it to a 4 bank select HLN4298A. None of the other bank select boards have the PTT connection to handle the false mode 32 display. If you convert a HLN4296A into a HLN4298A you will find Motorola no longer sells the A, B, C and D escutcheon, but the old Micor F1, F2, F3 and F4 escutcheons can be salvaged and they work just fine.

System 90*s operator select non-priority scan modules:

HLN1059A - Alternate Control Module Operator Select Channel Scan, 8 Non-Priority Modes
TRN4326A - 5 Mode Operator Select Scan with Display board (use with non-scanning TRN4343 or Clamshell) {S9s-2} **
TLN2256A - 5 Mode Operator Select Scan with Display Kit w/ TRN4326A , Hardware & Escutcheon
HLN4290A - 8 Mode Operator Select Scan with Display board (use with non-scanning TRN4344 or Clamshell) {S9s-2} **
TLN1059A - 8 Mode Operator Select Scan with Display Kit w/ HLN4290A , Hardware & Escutcheon, photo
TRN4328A - 2 Mode Scan Indicators board {S9s-2} **
TRN4332A - 5 Mode Scan Indicators board {S9s-2} **
TLN2259A - 5 Mode Scan Indicators Kit w/ TRN4332A , Hardware & Escutcheon
TRN4336A - 8 Mode Scan Indicators board {S9s-2} **
TLN2261A - 8 Mode Scan Indicators Kit w/ TRN4336A , Hardware & Escutcheon

• ** - These boards supply the Mode Strobe signal.
• All of these boards only work with the Syntor X radio line because of their unique interface.
• For non-priority operator select scan select boards, all "Scan" really means is the board has a switch (labeled PRI) to ground J1-31 (Channel Scan Enable) to activate the radios scanning.
• Up to 4 of the HLN4290A boards can be used to select and display 32 non-priority scan modes (8 modes per board). The radio can be programmed to use these boards or its internal non-priority scan list, but it can not use both together. Many radios with 16 or 32 mode control heads only have a single HLN4290A board so programming the radio to use the board will limit them to 8 operator selectable non-priority scan modes. If the radio's internal non-priority scan list is programmed all 32 modes can be used, but then the HLN4290A board can not be used to select any modes. Each mode in the radio can be individually programmed to use the internal non-priority scan list or to use the HLN4290A board, however, it can never use both at the same time.
• The TRN4336A and TRN4290A are both victims of the false mode 32 display. If the boards are jumpered for modes 25-32 (bank D) the mode 8 light will light up when a scan is started. The lights will display correctly when the scan stops on an active mode. There is no cure for these boards.
• The 8 mode boards are used to make 5 mode or 2 mode boards by not fully populating the board with parts.

System 90*s operator select multiple PL/DPL modules (MPL):

TRN4322A - 4 Code MPL Operator Select board {S9s-3} **
TLN2254A - 4 Code MPL Operator Select Kit w/ TRN4322A & Hardware, Conventional 800 MHz only
HLN1057A - 4 Code MPL Operator Select Kit w/ TRN4322A , Hardware & Escutcheon
TRN4324A - 8 Code MPL Operator Select board {S9s-3} **
TLN2255A - 8 Code MPL Operator Select Kit w/ TRN4324A & Hardware, Conventional 800 MHz only
HLN1058A - 8 Code MPL Operator Select Kit w/ TRN4324A , Hardware & Escutcheon, photo

• ** - These boards supply the Mode Strobe signal.
• All of these boards only work with the Syntor X radio line because of their unique interface.
• The radio must be programmed to use these MPL boards.
• The 8 mode boards are used to make 4 mode boards by not fully populating the board with parts.

System 90*s and System 90 optional equipment:

HLN1019A - Singletone Encoder, 1 Tone
TLN4525A - Singletone Encoder, 1 Tone Circuit Board
HLN1020A - Singletone Encoder, 5 Tone
TLN4526A - Singletone Encoder, 5 Tone Circuit Board
HLN1021A - Auxiliary Switch Panel
HLN1022A - Voice Privacy Adapter (VPA), simple frequency inversion
TLN4571A - VPA circuit board
TKN6520A - VPA hookup cable (control head to VPA)
HLN1023A - "Touch-Code" Mobile Encoder
TLN5837A - "Touch-Code" Mobile Encoder circuit board (6, 7, 8, 9, 0, # keys)
TTN6006A - "Touch-Code" Mobile Encoder supplemental switching circuit board (1, 2, 3, 4, 5, * keys)
TKN6731A - "Touch-Code" Mobile Encoder interconnecting cable
HLN1024A - "Touch-Code" Mobile Selective Signaling Decoder Kit w/ TRN6015A, photo
TRN6015A - "Touch-Code" Mobile Selective Signaling Decoder circuit board, photo
HLN1018A - Public Address circuit board (uses radio's audio amplifier)
HLN1025A - Siren, wail-yelp-steady pitch
TRN4223A - Siren, control board, wail-yelp-steady pitch
HLN1026A - Siren, wail-yelp-Hi-Lo
TRN4222A - Siren, control board, wail-yelp-Hi-Lo
TRN1691B - Siren/Public Address audio power amplifier
TKN6754A - Siren Cable kit
HLN1017A - Quick Call II 2 Reed Decoder & 4 Reed Group Call Decoder
TLN4523A - Quick Call II 2 Reed Decoder Circuit Board
TLN4522A - Quick Call II 4 Reed Decoder Circuit Board
HLN4270A - Internal Retrofit Board: EMS, Single Tone Encoder, MDC-600 and 110/10 watt VHF T83 radios.
HLN1079A - EMS Rear Control Group with Headset
HLN1080A - EMS Rear Control Group with Handset
TRN4221A - EMS Rear Control Board
HLN1042A - EMS Transfer Module
HLN4312A - EMS Transfer Board
HLN1146A - Internal Retrofit Board, Mobile Voice Storage MVS-20 (includes MDC-600 retrofit)
HLN1117A - MVS-20 (Mobile Voice Storage - MVS)
HLN1146A - MVS-20 (Mobile Voice Storage - MVS) Syntor X Retrofit
HLN4535A - MVS-20 Circuit Board
HLN1068A - MDC-600 Unit Identification
HLN4302B - MDC-600 PTT ID Circuit Board
HLN1077A - MDC-600 Selective Call Decoder, photo
HLN4347A - MDC-600 Selective Call Decoder Circuit Board, photo
HLN1069A - MDC-600 Selective Call Encoder/Decoder
HLN4303B - MDC-600 Selective Call Encoder/Decoder Circuit Board
HLN1070A - MDC-600 Five Status with Alarms
HLN4304B - MDC-600 Five Status Circuit Board
HLN1071A - MDC-600 Five Status/One Message
HLN4305B - MDC-600 Status/Message Circuit Board
HLN4343A - MDC-600 Emergency Footswitch
HLN4349A - MDC-600 Emergency Pushbutton
TRN4394A - Adaptor Cable (800 MHz Radio Only)
TRN4353A - Interface Board, used with TRN4394A (800 MHz Radio Only)
HLN4423B - Securenet DVP One Code Board
HLN4424B - Securenet DVP Two Code Board
HLN5244A - Securenet DVP Bypass Board

• The DVP Bypass Board allows a "VXJ" radio that is jumpered for and cabled for DVP to be used for normal voice communication without having to re-jumper the radio's Personality Board or re-wire the cable. This board is used in place of the DVP board and it has no front panel switches.

HHCH control head and accessoriess:

HCN4026 - Handheld Control Head, Securenet
HCN4027 - Handheld Control Head, Securenet, Non-Priority Scan Control
HCN4028 - Handheld Control Head, Non-Priority Scan Control
HCN4029 - Handheld Control Head
HKN4190 - Internal Controller Board Cable
HKN4216 - Radio to HHCH (Non-SecureNet)
HLN1170 - SecureNet Junction Box
HKN4187 - Radio to Junction Box Cable (SecureNet)
HKN4188 - Junction Box to Physical Security Housing Cable (SecureNet)
HKN4215 - Junction Box to HHCH Cable (SecureNet)
HHN4014 - Physical Security Housing (SecureNet)
HLN4849 - Junction Box Board
HKN4190 - Cable Controller Board
HHN4015 - Securenet Physical Security Housing, Single Card
YHN4006 - Securenet Physical Security Housing, Dual Card
YCN4014 - Handheld Control Head, Securenet, Zone/Channel
YCN4015 - Handheld Control Head, Securenet, Group/Channel
YCN4017 - Handheld Control Head, Securenet, Dual Code, Group/Channel
YLN4194 - Siren/PA Control Box
YLN1046 - System Interface Unit w/Siren/PA Interface
YLN1056 - System Interface Unit
YLN1056ASP02 - System Interface Unit, Dual Code
YLN4187 - Control Head Interface Board
YLN4188 - Siren/PA Interface Board
YHN4001 - System Interface Unit housing w/ Siren/PA
YHN4005 - System Interface Unit housing
YKN4112 - Radio Control Cable
YKN4113 - Control Head Control Cable
YKN4114 - Siren/PA Cable
YKN4116 - Securenet Control Cable
YKN4116BSP01 - Securenet Control Cable, Dual Code
YKN4129 - Securenet Control Cable
YKN4188 - Siren/PA Cable
HLN1099 - Securenet Control Board
YLN4405 - Securenet Dual Code Control Board
TLN4404 - Securenet Dual Code Board
TLN1691BSP02 - Siren/PA Power Amplifier
YLN4209 - Transmitter Modification
TRN4838 - Securenet DES Encryption Hybrid
HSN1001 - Speaker, special connector for HHCH cable - Renumbered to HSN4018A
YSN1003 - Speaker, special connector for HHCH cable - Renumbered to HSN4018A
HLN4830 - Hang-up Box

• The hand held control head also requires the HLN4728A - Hand Held Control Head Interface Board to be installed in the Syntor X radio.
• The HCN4026 and HCN4029 control heads can be field programmed with the non-priority scan list. However, the procedure involves removing the bottom cover of the radio. The other two HCN4027 and HCN4028 control heads easily program the non-priority scan list directly from the control head.

PAC-RT and PAC-PL Vehicle Repeater:

Please see the PAC page for information on the PAC-PL and PAC-RT.

Syntor X accessories:

HMN1015A - Microphone, Weather Resistant
HMN4000B - Microphone, Weather Resistant
TMN6116A - Microphone, noise canceling
HMN4002A - Microphone
HMN1022B - DTMF Microphone, Non-Trunked
HMN1014B - DTMF Microphone, Trunked
HLN4188A - Microphone Hangup Box
TMN6057A - Handset, simplex
TMN6067A - Handset, duplex
TMN6152A - Handset, trunking
TMN6090A - Headset w/pre-amp and lip mic
TLN5557A - Headset footswitch
HSN4005A - Speaker, 15 watts, 8' cable
HSN4006A - Speaker, 15 watts, 25' cable
HSN4011A - Speaker, 20 watts, 12' cable, weather resistant
TSN6016B - Speaker, 10 watts, 10' cable, X3 trunked radio only
07-84567B01 - Speaker hangar bracket
14-84566B01 - Speaker Connector Housing (use 09-84151B03 pins - same as cable and control head pins)
TAB1002C - Low Band Antenna with Spring Base
01-80016K02 - Radio Mounting Tray

• Many accessories from older Motorola radio lines will also work with the Syntor X.
• The only difference between the HMN1022B and HMN1014B DTMF microphone is the jumpering. Motorola manual 68P81114E07-B has the jumpering information. An unmodified trunking microphone is still usable on a conventional radio, but the touch tones will be pre-timed bursts no matter how long you hold down the button.
• The Speaker hangar bracket also requires a 6-32 x 3/8" machine screw.

Internal options for the Syntor X:

HLN4728A - Hand Held Control Head Interface Board
TRN8868A - 800 MHz Rx pre-amp
HLN1087A - Fusible Link PROM Module (early Syntor X radios), White Label
HLN1088A - Fusible Link PROM Module (early Syntor X radios), White Label
HLN1089A - Fusible Link PROM Module (early Syntor X radios), White Label
HLN1125A - Re-programmable (2816A) EEPROM Module, Orange Label

Special Syntor X parts:

In general, Motorola part numbers that start with a "Y" are special order variations of standard parts (i.e. YCN1009A would be a factory customized variation of the HCN1009A). These parts can be quite useful, but you will have to figure them out on your own unless you are fortunate enough to get the documentation with them.

Control head diodes:

Missing diodes: an important difference between the Syntor and Syntor X clamshell control heads is the Syntor X clamshell control heads have diodes added to the mode selector outputs. When the control head is used with any System 90*s accessories that connect to the mode lines (see example cable wiring pin out for a clamshell control head), the diodes allow the clamshell control head to be electronically removed from circuit. If the diodes are not present (i.e. as with Syntor clamshell control heads) the control head will mess things up when the radio attempts to communicate with System 90*s accessories that use the mode lines. You can only use Syntor clamshell control heads on a Syntor X when there are no other System 90*s options that use the J1 cable mode lines connected to the radio. The EEPROM should also be programmed to not do anything that causes the radio to try and communicate with any System 90*s non-priority scan and MPL options, the "display enable" line on the cable should be disconnected and finally JU14 the display enable jumper should be removed (JU14 is only on the HLN4760A, B and C Personality Boards, but remember to check the other Personality Boards for custom jumpers on the trace side of the Personality printed circuit board).

The HCN1009A clamshell control head is a hold-over from the original Syntor radio line that lacks the diodes, so it should follow the above rules for Syntor control heads. When an 8 mode control heads is mixed with System 90*s accessories that use the mode lines, the 8 mode System 90*s alternate control module should be used instead of this clamshell. The other option is to modify the 8 mode clamshell control head and add the diodes yourself. It will still need to be correctly connected to the cable (see example cable wiring pin out for a clamshell control head).

The System 90*s alternate control modules (i.e. pushbutton mode control heads) also have different methods of releasing the M1-M8 mode lines as well as using "mode strobe" and diodes. They use logic chips that use the "control head strobe" signal and decode the M9-M12 address from the radio instead of diodes. Again, like the Syntor clamshell without diodes, if you set up the EEPROM, jumpering, display enable and do not use any System 90*s options that connect to the mode lines, you can use older Syntor pushbutton mode select control heads parts. If you break these rules a Syntor X radio may display strange behavior because the mode selector will interfere with the radio when it attempts to use the mode lines to communicate with other System 90*s options.

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PL, Private Line, DPL, Digital Private Line, MPL, Talkaround, MDC-600, MDC-1200, MVS-20, Securenet, Smartnet, Privacy Plus, Trunked X2, Trunked X3, Touch Code, Quick Call II, Channel Scan, Talkback Scan, System 90, System 90*s, Systems 9000, Mitrek, Micor, Spectra, MataTrac, Syntor, Syntor X, Syntor X 9000 and Syntor X 9000E are trademarks of Motorola Inc.