Daniels Electronics MT-3 Instruction Manual page 15

time-out-timer Circuitry
The MT-3 FM Transmitter also has an
associated programmable push-to-talk
(PTT) time-out-timer (TOT) circuitry on the
transmitter mainboard. The TOT circuitry
is powered via J34 from the continuous
+9.5 VDC supply and is programmable for
various time-out periods.
The TOT input trigger (enabled by J33) is
normally high and in this state the timer is
disabled. When the input trigger level falls
below +2.0 VDC, the timer is activated, the
TOT output trigger (enabled by J35) is pulled
low and the transmitter is keyed. If the input
trigger rises above +2.4 VDC or if the time-
out period is exceeded, the output trigger will
go high, disabling the transmitter. If the time-
out period is exceeded, the TOT input trigger
must go high and then low again in order to
re-key the transmitter.
The time-out duration is jumper selectable
from 1 second to 8 hours (see Table 1).
The positions of the jumpers are on the
top (through-hole component) side of the
transmitter mainboard.
TABLE 1: Time-out Jumper Settings and Duration
J32 J31 J29 J28 J26 J27
I I I I
I I I I
I I I I
I I I n/I
I I I n/I
I I n/I I
I I I n/I
I I n/I I
I I n/I n/I
I I n/I I
I I n/I n/I
I n/I I I
I I n/I n/I
I n/I I I
I n/I I n/I
I n/I I I
I n/I I n/I
I n/I n/I I
I n/I I n/I
I n/I n/I I
I n/I n/I n/I
I n/I n/I I
I n/I n/I n/I
n/I I I I
I n/I n/I n/I
n/I I I I
n/I I I n/I
n/I I I I
N/I I I N/I
n/I I n/I I
n/I I I n/I
n/I I n/I I
n/I I n/I n/I
n/I I n/I I
n/I I n/I n/I
n/I n/I I I
n/I I n/I n/I
n/I n/I I I
n/I n/I I n/I
n/I n/I I I
n/I n/I I n/I
n/I n/I n/I I
n/I n/I I n/I
n/I n/I n/I I
n/I n/I n/I n/I
n/I n/I n/I I
n/I n/I n/I n/I
n/I n/I n/I n/I
N/I = Not Installed
I = Installed
Bold text represents default settings.
MT-3 FM Transmitter Mainboard Instruction Manual
Theory of Operation
Minutes
I I 0.01
I n/I 0.01
n/I I 0.01
I I 0.01
I n/I 0.02
I I 0.02
n/I I 0.03
I n/I 0.04
I I 0.05
n/I I 0.06
I n/I 0.08
I I 0.10
n/I I 0.12
I n/I 0.15
I I 0.19
n/I I 0.23
I n/I 0.31
I I 0.38
n/I I 0.47
I n/I 0.62
I I 0.75
n/I I 0.94
I n/I 1.25
I I 1.5
n/I I 1.88
I n/I 2.5
I I 3.0
n/I I 3.75
I N/I 5.0
I I 6.0
n/I I 7.5
I n/I 10
I I 12
n/I I 15
I n/I 20
I I 24
n/I I 30
I n/I 40
I I 48
n/I I 60
I n/I 80
I I 96
n/I I 120
I n/I 160
I I 192
n/I I 240
I n/I 320
n/I I 480
IM20-MT3TXMN
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