OPTION
DESCRIPTIONS
J2 DC Level Shift Output (74HC type)
Level:
TTL/CMOS
compatible
Load:
6
mA
sink
1.4 ADJUSTMENTS
Phase: While observing the modulated output (J1) on an oscilloscope, adjust R14 for minimal
discontinuity at the modulation points.
Ratio: While observing the modulated output (J1) on an oscilloscope, adjust R15 for the desired
ratio. The standard modulation ratio for IRIG time codes is 3:1.
Levels: While observing the modulated output (J1) on an oscilloscope, adjust R16 for the desired
level. The standard amplitude for most applications is 3 V p-p (modulated carrier), which is
approximately
1 V RMS.
R2
1
R1
8
R1
9
R2
0
C11
R17
Q1
C10
R15
R16
R14
J1
J2
TP2
TP1
R11
R6
Symmetricom, Inc.
TM7000 TymMachine TCG/T (Rev D)
A-29