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Motorola MSF5000 SSCB Signals
Compiled by Robert W. Meister WA1MIK
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This is a compilation of the signals on the SSCB schematic. The entire SSCB section from a UHF station service manual has been scanned and can be found here as a 1.3MB PDF file. The page numbers shown in the tables below reference the schematic diagram page (1-9 of 9 pages), NOT the PDF file page. Most of the pages were fold-out and were scanned as two separate halves, but everything is present.

Notes for all tables:
    1. An asterisk (*) after a signal name indicates active low (to ground).
    2. Src = page number where signal originates or enters via a connector.
    3. Dst = page number(s) that signal goes to leaves via a connector.

SSCB Schematic Inter-page Signals:

This table shows the various signals that travel between schematic pages.

Abbreviations used in the "Notes" column:
    1. DISPLAY = signal used for front panel display.
    2. EEPOTS = signal used for all Electronically Erasable Potentiometers.
    3. EEPOT n = signal used for one specific EEPOT.
    4. POST = used primarily for Power On Self Tests.

Signal NameSrc DstNotes
ALERT TONE 0..341 
ALERT TONE AUDIO16,8 
ALERT TONE LINE GATE56 
ALERT TONE SAMPLE13POST
ALERT TONE TX GATE56,7 
CHAN ACT93 
CODED MOD AUDIO_117 
COMPANDOR ENABLE47,9 
DELAYED RESET34 
DIGIT 1..331DISPLAY
DISPLAY ON31 
FAST KEY13 
FF ENABLE48,9 
FF LEVEL*48EEPOT 1
FWD PWR13 
LEVEL INC47,8,9EEPOTS
LEVEL U/D*57,8,9EEPOTS
LINE AUDIO SAMPLE73POST
LOCAL GATE56 
LOOPBACK58 
MAX DEV LEVEL*47EEPOT 4
MOD AUDIO SAMPLE73POST
MPTSQ91,5 
MRTI GATE56 
PL AUDIO SAMPLE13POST
PL DECODE DATA83 
PL ENCODE AUDIO17 
PL/CT 0..341 
PL/CT SELECT41 
PL/DPL*58 
PREDE/FLAT*47,9 
RCVR SQ LEVEL*49EEPOT 3
REPEATER GATE56 
RESET23 
RESET_SWITCH32 
RFL PWR13 
RPTR SQ LEVEL*49EEPOT 2
RPTR UNSQ93 
RX LEVEL*48EEPOT 5
RX1 AUDIO96 
RX1 AUDIO SAMPLE93POST
RX1 GATE56 
RX1 UNSQ93 
RX1*/RX248 
SEGMENT a..g,dec41DISPLAY
SQ ADAPT59 
SQUELCH EEPOT ENABLE*49 
SYSTEM AUDIO SAMPLE73POST
TX GATE56 

Expansion Connector J800 Signals:

This two-row connector is found on top of the plastic control tray, into which you can attach an expansion tray, a programming cable, or a metering panel.

PinSignal Name SrcDst
1A++22
2A++22
3A++22
4A++22
5A++22
6AUDIO GND22
7AUDIO GND22
8AUDIO GND22
9AUDIO GND22
10AUDIO GND22
11IPCB33
12EXPANSION RESET*33
13BA044
14BA144
15BA244
16BA344
17BD0*44
18BD1*44
19BD2*44
20BD3*44
21LOGIC GND22
22DS*44
23SHUTDOWN*22
24LOGIC SPARE11
25LOGIC SPARE11
26AUDIO SPARE11
27AUDIO SPARE66
28GEN TX DATA11
29QUAD 2 AUDIO99
30DIVERSITY AUDIO88
31GCC/RAC DATA AUDIO77
32SELECT AUDIO67
33LOCAL AUDIO66
34TX DATA AUDIO77
35RX2 AUDIO66
36TX AUDIO67
37AUDIO GND22
38RX1 AUDIO99
39QUAD 1 AUDIO99
40AUDIO GND22

RF Tray Connector J801 Signals:

This two-row connector feeds signals to and from the RF Tray through a flat cable.

PinSignal Name SrcDst
1+9.6V22
2RX2 LOCK*34
3TX MOD AUDIO77
4AUDIO GND (GND A)22
5RAW RX1 AUDIO88
6RAW RX2 AUDIO88
7ANTENNA RELAY ENABLE*45
8TX LOCK*34
9RX2 STROBE45
10PA FULL POWER*34
11AGC REF *(800/896)88
12PA ON*34
13RX1 LOOP34
14PA KEY*45
15RX1 LOCK*34
16POWER CUTBACK*45
17SD044
18TX LOOP34
19SD144
20SA244
21SD244
22SA144
23SD344
24SA044
25RX1 STROBE45
26TX STROBE45

MRTI Connector J802 Signals:

This single-row connector can either be 14 or 20 pins, and the layout is slightly different.

PinPin Signal NameSrcDst
11LOGIC GND22
22MRTI PL STRIP*34
33LOGIC GND22
44MRTI MONITOR*34
55MRTI PTT*34
66LOGIC GND22
77AUDIO GND22
88IN MRTI AUDIO66
99LOGIC GND22
1010OUT MRTI AUDIO67
1111MRTI RX CARRIER45
1212MRTI INHIBIT45
13---N.C.----
1414MRTI AUX INDICATE45
15---N.C.----
16---A++22
17---A++22
1813AUDIO GND22
19---N.C.----
20---N.C.----

Secure Board Connector J803 Signals:

This two-row connector feeds the secure board that mounts on plastic standoffs on top of the SSCB board.

PinSignal Name SrcDst
1AUDIO GND22
2AUDIO GND22
3+9.6V22
4SECURE RX AUDIO66
5TX AUDIO67
6RAW TX AUDIO67
7CODED MOD AUDIO77
8LOCAL AUDIO67
9HSR IN45
10LOGIC GND22
11HSR TO SECURE45
12LOGIC GND22
13HSR CLOCK45
14LOGIC GND22
15HSR SYN45
16LOGIC GND22
17BD3*44
18BD2*44
19BD1*44
20BD0*44
21BA344
22BA244
23BA144
24BA044
25DS*44
26N.C.11
27QUAD AUDIO99
28IN MRTI AUDIO67
29IPCB33
30LEVEL U/D*45
31LEVEL INC44
32CODED MOD LEVEL*44
33EXPANSION RESET*33
34SECURE ALERT TONES66
35CODED RX LEVEL*44
36N.C.11
37KEY BATTERY GND22
38CODED MOD AUDIO_117
39+5V22
40AUDIO GND22

TTRC Board Connector J804 Signals:

This two-row connector feeds the Trunked Tone Remote Control (TTRC) cards that install in the plastic control tray.

PinSignal Name SrcDst
1A++22
2AUDIO GND22
39.6V22
4LINE AUDIO67
5TX AUDIO67
6RAW TX AUDIO66
7TKG MOD AUDIO77
8QUAD AUDIO99
9HSR OUT45
10LOGIC GND22
11HSR FROM TTRC45
12LOGIC GND22
13HSR CLOCK45
14LOGIC GND22
15HSR SYN45
16LOGIC GND22
17BD3*44
18BD2*44
19BD1*44
20BD0*44
21BA344
22BA244
23BA144
24BA044
25DS*44
26IPCB33
27CONNECT TONE AUDIO11
28EXPANSION RESET*33
29MUTE33
30GEN TX DATA11
31+5V22
32A++22
33+5V22
34AUDIO GND22

Control/Microphone Connector J812 Signals:

This 6-position, 6-contact (6P6C) modular jack is used for a local microphone, handset, or programming cable.

PinSignal Name SrcDst
1LOGIC GND22
2AUDIO GND22
3MIC AUDIO66
4MIC PTT*33
5SPKR AUDIO77
6IPCB33

DC Power Connector J701 Signals:

This large 6-pin Molex connector is the main power feed for the control tray.

PinSignal Name SrcDst
1A++ (AUX +13.8V)22,7
2KEYWAY (NO PIN)------
3OVERVOLTAGE ALARM*34
4BATTERY REVERT* (AC FAIL*)34
5GND B11
6NORMALIZED IF ENVELOPE (800/896)88

Contact Information:

The author can be contacted at: his-callsign [ at ] comcast [ dot ] net.

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This article first compiled 13-Sep-2006.


Article text and hand-coded HTML © Copyright 2012 By Robert W. Meister WA1MIK.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.