MT-3 FM Transmitter Mainboard Instruction Manual
IM20-MT3TXMN
51
reVISIon
HIStory
Revision History continued next page
Revision
Date
Action #
Description
3
Mar 02
701
TOT specification changed from 5min ± 30sec to 5min ± 50sec.
3
Apr 02
697
Improve hum & noise performance, UT-3/8xxx only Version 2.3 Audio
Processor changes
C56 now 22nF for 800 MHz LTR™ only (remains as 33nF for
•
other bands.)
JU29, JU32, and JU44 Not Installed for 800 MHz LTR™
•
3
Feb 02
678
To prevent frequency error when PTT first activated. Reduction of
charge time for C34 on the Version 2.3 Audio Processor.
C34 now 1.0µF, DIP Tantalum (was 47µF SM Tantalum)
C34 remains as 47µF for LTR™ & DCS applications.
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4
Mar 03
Reissue including Version 2.3 Audio Processor information.
•
Version 1.6 Audio Processor information is removed.
•
Issue 4 covers Version 1.8, 2.2 & 2.3 Audio Processors.
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Issue 4 contains no AM information - the document title is
•
changed to reflect coverage of only FM transmitters.
699
For VT-3H035 & VT-3H045 transmitters, to reduce spurious emissions
for CE approval, the PCB trace pattern is modified and C44 is Not
Installed.
701
Time Out Timer tolerance is changed to ±17%. Tolerance for 5 minutes
setting is ± 50sec.
4-1-0
Sep 03
New Manual Format
•
Removed all reference to Version 1.8 Audio Processor
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4-1-1
Oct 03
Typographical updates to manual.
4-2-0
Jan 05
660
Update Audio Processor Component Layout Dwg:
•
43-911923-01-T-01-01 to 43-911923-01-T-02-01
43-911923-01-S-0101 to 43-911923-01-S-02-01
Add Select table for Audio Processor Components:
•
“Audio Processor Component Layout Selection Table”
791
Update Main Board Component & Schematic Dwg to update J25 SEL:
X installed for FM Products & Y installed for AM Products
---
Update Tx Front Panel Component Dwg:
•
43-921212-01-T-01-01 to 43-921212-01-T-02-01
Update specification tables and part list
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