UNIVERSAL DIGITAL AND DATA INTERFACE
B-4
Revised May 1998
Part No. 001-9750-006
Figure B-3 Transmit Audio Signal Routing
Table B-4 Transmit Audio Pin Description
Function
Pin
Description
Tx Mic Out
11
Buffered single-ended microphone signal before any filtering. DC coupled with 3.2-volt DC bias.
Output impedance less than 200 ohms. Output level 1V P-P nominal. This output is shared with
internal option wire-out 3.
Tx Mic In
12
Input before 300-3000 Hz TIA bandpass filtering, pre-emphasis, and limiting. Therefore, this input
signal will pass through these circuits. The input impedance is greater than 24k ohms, and the
nominal input level is 1-volt P-P at 60% system deviation. This input is shared with internal option
wire-out 4.
Tx ECD In
13
This External Coded Data input bypasses bandpass filtering but not pre-emphasis and limiting. It
could be used for modems and other equipment that produce signaling in the 4 Hz - 3000 Hz range.
AC coupled with input impedance greater than 20k ohms, and nominal input level is 1-volt P-P at
60% system deviation.
Tx WB In
20
This wideband data input permits direct modulation of the transmit signal since it is after the filter-
ing and deviation limiting circuitry. When the standard DC coupling is used, a DC bias of 2.5 volts
±2% (50 mV) must be applied to this input. This keeps the TCXO on frequency since there is then
a DC path directly to the TCXO modulation input. The TCXO frequency may need to be read-
justed when DC coupling is used. Nominal input level is 1-volt P-P at 60% system deviation.
Optional AC coupling is available by removing jumper R707 on the audio/logic board. AC cou-
pled input impedance is greater than 20k ohms. Frequency response is DC - 4800 Hz (DC coupled)
or 4 Hz - 4800 Hz (AC coupled).
NOTE: Since signals on this input bypass the deviation limiting
circuitry, the user assumes all responsibility for FCC compliance when this port is used.
Table B-5 Transmit Audio Programming
Device
Mode
M4
M5
M6
M7
(Default)
1
Closed
Open
Open
Open
Device A
2
Open
Closed
Open
Open
Device B
3
Open
Closed
Closed
Open
Device C
4
Open
Closed
Open
Closed
Device D
3
Open
Closed
Closed
Open
Device E
4
Open
Closed
Open
Closed
Bandpass
Filter
Device
A
Device
B
Device
E
Device
D
M4
M6
Pre-Emphasis/
Limiter
Filter
Splatter
M7
To
Synthesizer
M5
Device
C
Tx
Mic Out
Tx
Mic In
Tx
ECD In
Tx
WB In
NOTES:
1. Gates M4 and M5 are complementary only, and cannot be controlled independently.
2. M4/M5 - Tx Loop Enable, M6 - Tx ECD Enable, M7 - Tx WB Enable
Methods of
Connecting
External
Devices To
Universal
Interface
Summary of Contents for Summit DM 975x
Page 105: ...MULTI NET SYSTEM OVERVIEW 5 10 Revised February 1997 Part No 001 9750 005 ...
Page 108: ...CIRCUIT DESCRIPTION 6 3 August 1993 Part No 001 9750 001 Figure 6 1 Transceiver Block Diagram ...
Page 123: ...CIRCUIT DESCRIPTION 6 18 August 1993 Part No 001 9750 001 ...
Page 131: ...SERVICING 7 8 Revised January 1995 Part No 001 9750 003 ...
Page 156: ...9 19 Revised December 2000 Part No 001 9750 007 TRANSCEIVER EXPLODED VIEW PART 1 ...
Page 168: ...Revised January 1995 Part No 001 9750 003 10 11 INTERCONNECT SCHEMATIC ...
Page 169: ...Revised January 1995 Part No 001 9750 003 10 12 DISPLAY BOARD SCHEMATIC ...
Page 171: ...Revised January 1995 Part No 001 9750 003 10 14 RF BOARD SCHEMATIC REVISED 800 MHZ ...
Page 172: ...Revised January 1995 Part No 001 9750 003 10 15 RF BOARD BOARD LAYOUT ALL 800 900 MHZ ...
Page 173: ...Revised January 1995 Part No 001 9750 003 10 16 RF BOARD BOARD SCHEMATIC 900 MHZ ...
Page 174: ...Revised January 1995 Part No 001 9750 003 10 17 RF BOARD BOARD SCHEMATIC UNREVISED 800 MHZ ...
Page 178: ...Revised January 1995 Part No 001 9750 003 10 21 PA BOARD SCHEMATIC 900 MHZ 30W ...
Page 179: ...Revised January 1995 Part No 001 9750 003 10 22 PA BOARD SCHEMATIC 900 MHZ 15W ...
Page 181: ...Revised January 1995 Part No 001 9750 003 10 24 PA BOARD SCHEMATIC UNREVISED 800 MHZ 35W ...
Page 182: ...Revised January 1995 Part No 001 9750 003 10 25 PA BOARD SCHEMATIC UNREVISED 800 MHZ 15W ...
Page 183: ...Revised January 1995 Part No 001 9750 003 10 26 AUDIO LOGIC BOARD SCHEMATIC PART 1 OF 2 ...
Page 184: ...Revised January 1995 Part No 001 9750 003 10 27 AUDIO LOGIC BOARD SCHEMATIC PART 2 OF 2 ...
Page 185: ...Revised January 1995 Part No 001 9750 003 10 28 AUDIO LOGIC BOARD LAYOUT TOP VIEW ...
Page 186: ...Revised January 1995 Part No 001 9750 003 10 29 AUDIO LOGIC BOARD LAYOUT BOTTOM VIEW ...
Page 188: ...Revised January 1995 Part No 001 9750 003 10 31 REMOTE TRANSCEIVER INTERCONNECT SCHEMATIC ...
Page 189: ...Revised January 1995 Part No 001 9750 003 10 32 REMOTE CONTROL UNIT INTERFACE BOARD SCHEMATIC ...
Page 216: ...Part Number 001 9750 007 12 00 hph Printed in U S A ...
