MT-3 FM Transmitter Mainboard Instruction Manual
IM20-MT3TXMN
Interconnect Pins and Jumper Configuration
33
TABLE 3: FM Audio Processor Default / CTCSS / LTR
®
/ DCS Configurations
NOTE
:
Synthesizer uses Rakon TCVCXO VTXO250U-5 +/- 5 ppm stability
for low band transmitter CTCSS and LTR
®
/ DCS.
Audio Processor (V 2.3) Low Band TX Jumper Table
Jumper
Type
Default
Position
Description
Pre-emphasis /
CTCSS
Flat / CTCSS
Pre-emphasis / LTR® /
DCS
1
XY
Y
Microphone Pre-Emphasis / Flat Audio
Y
X
Y
2
XY
Y
Balanced Audio Pre-Emphasis / Flat Audio
Y
X
Y
3
XY
Factory
Custom Temperature Compensation Network
Contact Factory
Contact Factory
Contact Factory
4
XY
Open
Subtone 2
Open
Open
Open
5
XY
Open
Auxiliary Input Routing
Open
Open
X
6
Single
In
Splatter Filter Output
Installed
Installed
Installed
7
Single
Open
Auxiliary Input Routing
Open
Open
Open
8
Single
Open
Direct Coupled Final OP-Amp O/P
Open
Open
Open
9
XY
Open
Auxiliary Output for Pre-Emphasis
Open
Open
Open
<<Updated by Eva June 12-08
10
Single
Open
4 V AC Ground
Open
Open
Installed
11
Single
Open
Balanced Input Compression Bypass
Open
Open
Open
12
XY
Open
Tone / Digital Input Audio Routing
Open
Open
Open
13
Single
Open
Direct Modulation Audio Routing
Open
Open
Open
14
XY
Open
Two Port Polarity Select
Y
Y
Open
15
XY
XY
4 V Regulator Adjust (Bypassed)
X and Y both
X and Y both
X and Y both
16
Single
In
Subaudible Enable
Installed
Installed
Open
17
Single
Open
Balanced Input Adjust Range Extend
Open
Open
Open
18
Single
Open
Audio Gate Disable
Open
Open
Open
19
XY
Y
Voltage Select (+9.5 V / 8 V) Audio Gates
Y
Y
Y
20
XY
Open
Direct Modulation Audio Routing
Open
Open
Open
21
XY
X
Audio Gate Switch
X
X
X
22
XY
Y
Splatter Filter Enable / Bypass
Y
Y
Y
23
Single
Open
Narrow Band Gain Reduction
Open
Open
Open
24
XY
Factory
Custom Temperature Compensation Network
Contact Factory
Contact Factory
Contact Factory
1 of 2
y
p
p
y
y
y
25
XY
Open
Wide / Narrow Band Switched Select
Open
Open
Open
26
Single
Open
Auxiliary Output Routing
Open
Open
Open
27
XY
Open
Direct Modulation Input Offset Output
Open
Open
Open
28
Single
Open
Direct Modulation Input Routing
Open
Open
Installed
29
Single
Open
Coupling Capacitor Selection
Installed
Installed
Installed
30
N/A
N/A
This skipped designator has been deleted.
N/A
N/A
N/A
31
Single
Open
Splatter Filter Output Routing
Open
Open
Open
32
Single
Open
Coupling Capacitor Selection
Installed
Installed
Installed
33
Single
Open
Direct Input Coupling
–
Auxiliary amplifier
Open
Open
Open
34
XY
Open
Audio Routing
Open
Open
Open
35
XY
Open
Audio Routing
Open
Open
Open
36
XY
X
AGC Preamp Power Select
X
X
X
37
Single
Open
Direct Couple (TCXO)
Open
Open
Open
38
Single
In
Low Pass Enable
Installed
Installed
Installed
39
XY
X
Low Frequency Amplfier Bias Select
X
X
X
40
N/A
N/A
This skipped designator has been deleted.
N/A
N/A
N/A
41
Single
Open
Narrow Band Gain Reduction
Open
Open
Open
42
XY
Open
Direct Modulation Input Bias Select
Open
Open
Open
43
Single
Open
Direct Modulation Direct / Cap Couple
Open
Open
Open
44
Single
Open
Coupling Capacitor Selection
Installed
Installed
Installed
45
Single
In
Coupling Capacitor Selection (Default)
Installed
Installed
Installed
1 of 2
Audio Processor (V 2.3) Low Band TX Jumper Table
Note:
CTCSS (Pre-Emphasis / Flat)
LTR
®
/ DCS
1K0
1K0
51K1
51K1
N / I
N / I
10K0
10K0
1uF
47uF
33nF
33nF
Audio Processor
(TCXO Op-Amp)
Synthesizer uses Rakon TCVCXO VTXO250U-5 +/- 5ppm Stabilty for Low Band TX CTCSS and LTR
®
/ DCS.
R35
C56
R32
R81
R54
C34
2 of 2
