Tait T800 SL2 25W, Service Manual

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M8SL2-00-002-812
X800-56-PCB3 PCB Information G6.2.3
© Copyright Tait Electronics Limited August 2004. All rights reserved.
Backplane Links and Switches
The tables below explain the functions of each of the links and switches on the X800-56-PCB3 back-
plane.
Table 6.1 X800-56-PCB3 links
Link Function Notes
LN1,
LN2 Connects balanced audio from the receiver to the trans-
mitter.
For talk-through operation.
LN3 Connects Rx-Gate to Tx-Key.
LN4
Select between primary serial comms (link pins 2–3) or
secondary (link pins 1–2). Secondary serial comms is via the receiver and
transmitter Aux connectors (second D-ranges).
LN5
Connects Tx-Relay-Driver output from transmitter to
the coax relay.
LN6
Select between serial comms (link pins 1–2) or RSSI (link
pins 2–3) on pin 11 of SK6 (Auxiliary connector).
LN7 Links external (or T803) CTCSS audio to transmitter.
T803 CTCSS audio not available at time of publi-
cation.
LN8
Link pins 1–2. Connects unbalanced Rx audio
(‘Audio1’) to T803. Not to be used when CTCSS is
present on RX audio as internal CTCSS filtering cannot
be applied to this path. For CTCSS use the option below.
Adjust level using RV2. Level to T803 independ-
ent of Rx Line Level control.
Link Pins 2–3 and Pins 4–5. Changes the balanced Rx
Line audio output to unbalanced for the T803. This
option should be used when CTCSS is present on RX
audio so that the internal CTCSS filter can be applied.
Level to T803 controlled by RX Line Level control.
LN9
T854 transmitters (after S/N 13098764):
Select between Transmitter Aux-Out-0 (link pins 2–3) or
direct FWD power sense voltage (link pins1–2). The lat-
ter could be used for an externally fitted RF power indi-
cator or alarm.
If an internal alarm board is fitted Aux-Out-0
(link pins 2–3) becomes FWD power alarm out-
put.
Older T854 transmitters (s/n 13098764 or earlier):
Select between Transmitter Aux-Out-0 (link pins 2–3) or
Aux-Out-1 (link pins 1–2).
LN10
T854 transmitters (after S/N 13098764):
Select between direct FWD power sense voltage (link
pins 2–3) or direct REV power sense voltage (link
pins1–2). Could be used for an externally fitted RF
power indicator or alarm.
If an internal alarm board is fitted direct FWD
power sense voltage (link pins 2–3) becomes REV
power alarm output.
Older T854 transmitters (s/n 13098764 or earlier):
Selection between transmitter Aux-Out-1 (link pins 2–3)
or Aux-Out-2 (link pins1–2).
LN11
Connects RX CTCSS disable from the T803 to the
receiver.
LN12
Connects Tx-Relay-Driver output from the transmitter
to RX-Inhibit on the receiver. Recommended setting to prevent the receiver
mute from inadvertently opening.