Tait TEL0049 One way paging transmitters T857-26-1010 & T857-26 User Manual 8c500 a3 bk

Tait Limited One way paging transmitters T857-26-1010 & T857-26 8c500 a3 bk

Contents

Diagram of units

M850-00
T856/857 General Information
C1.3
Copyright TEL 31/09/98
The photograph in Figure 1.1 on the next
page will help you to identify the main
circuit blocks in the T856.
There is a similar photograph in Figure
4.4 which shows the main tuning and
adjustment controls.
Extending both these fold-outs will
allow you to refer to both photographs
while using the manual.
The photograph in Figure 1.2 on the next
page shows the T856 front panel con-
trols.
C1.4
T856/857 General Information
M850-00
31/09/98 Copyright TEL
Figure 1.1 T856 Main Circuit Block Identification Figure 1.2 T856 Front Panel Controls
1
234
5 6
7 8
A
B
C
9
10
Key:
1
2
3
4
5
6
7
low pass filter
PA
exciter drive amplifier
audio processor
VCO
regulators
synthesiser
8
9
10
A
B
C
microcontroller and CTCSS
duct for cabling to extra D-range (if fitted)
D-range
RF output
D-range connector (“D-range 1”) incl. audio in & DC in
(refer to Section 2.2 in Part F)
microcontroller
On LED
The On LED is lit when the
T856 is transmitting.
Carrier Switch
Keys the transmitter (while
disabling the 600Ω line and
microphone audio).
Supply LED
The Supply LED is lit when
DC power is supplied to the
transmitter.
Line Sensitivity
Sets the gain of the 600Ω line
input of the audio processor.
Microphone Socket
For connecting a T800-80 micro-
phone to allow local control of
the transmitter. The 600Ω line is
disabled when the PTT button is
pressed.
M850-00
T856/857 General Information
C1.5
Copyright TEL 31/09/98
The photograph in Figure 1.3 on the next
page will help you to identify the main
circuit blocks in the T857.
There is a similar photograph in Figure
4.5 which shows the main tuning and
adjustment controls.
Extending both these fold-outs will
allow you to refer to both photographs
while using the manual.
The photograph in Figure 1.4 on the next
page shows the T857 front panel con-
trols.
C1.6
T856/857 General Information
M850-00
31/09/98 Copyright TEL
Figure 1.3 T857 Main Circuit Block Identification Figure 1.4 T857 Front Panel Controls
1
23
45
6
8
9
A
B
C
7
Key:
1
2
3
4
5
6
7
low pass filter
exciter drive amplifier
audio processor
VCO
regulators
synthesiser
microcontroller and CTCSS
8
9
A
B
C
duct for cabling to extra D-range (if fitted)
D-range
RF output
D-range connector (“D-range 1”) incl. audio in & DC in
(refer to Section 2.2 in Part F)
microcontroller
On LED
The On LED is lit when the
T857 is transmitting.
Carrier Switch
Keys the exciter (while
disabling the 600Ω line
and microphone audio).
Supply LED
The Supply LED is lit when
DC power is supplied to the
exciter.
Line Sensitivity
Sets the gain of the 600Ω line
input of the audio processor.
Microphone Socket
For connecting a T800-80 micro-
phone to allow local control of
the exciter. The 600Ω line is dis-
abled when the PTT button is
pressed.
M850-00
T856/857 Functional Testing
C4.9
Copyright TEL 31/09/98
Figure 4.4 T856 Main Tuning & Adjustment Controls
R481
#CV475
C6
L1
RV320
shutdown
RV210
line sensitivity
SW230
carrier
=IC700
TCXO
L481
RV310
power control
RV220
compression level
RV805
CTCSS
level adjust
PL205 PL220 PL215 PL210
SK805
temperature
IC350 pin 3
RV330
shutdown
power level
The photograph printed at right
will help you to identify the main
controls used in tuning and adjust-
ing the T856.
There is a similar photograph in
Figure 1.1 which shows the main
circuit blocks.
Extending both these fold-outs will
allow you to refer to both photo-
graphs while using the manual.
C4.10
T856/857 Functional Testing
M850-00
31/09/98 Copyright TEL
M850-00
T856/857 Functional Testing
C4.11
Copyright TEL 31/09/98
Figure 4.5 T857 Main Tuning & Adjustment Controls
C6
L1
RV210
line sensitivity
SW230
carrier
=IC700
TCXO
RV220
compression level
RV805
CTCSS
level adjust
PL205 PL220 PL215 PL210
SK805
The photograph printed at right
will help you to identify the main
controls used in tuning and adjust-
ing the T857.
There is a similar photograph in
Figure 1.3 which shows the main
circuit blocks.
Extending both these fold-outs will
allow you to refer to both photo-
graphs while using the manual.

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