Specifications

5/2/2013 888-2500-001 6-37
WARNING: Disconnect primary power prior to servicing.
Section 6 Troubleshooting
DAX-1/DAX-3
External I/O DC VOLT ADJ TP19 Power supply control signal
Set by Exciter/Controller board
(Varies with RF power output level)
0 - 9Vdc
External I/O +3.3V TP20
DS10
Onboard regulation - IC
Green LED illuminates to indicate
+3.3V supply present
+3.3Vdc
External I/O INTLK DS1 Red LED illuminates to indicate open
Interlock loop
External I/O IBOC Mode
Selected
DS3 Green LED illuminates to indicate
IBOC Mode is currently selected
External I/O Analog Mode
Selected
DS4 Green LED illuminates to indicate
Analog Mode is currently selected
Exciter
Controller
DDS CLK TP1 High frequency master synthesizer
clock - 21.280 MHz to 42.240 MHz
(depending on carrier frequency)
TTL
Exciter
Controller
PM 4FC CLK TP2 Phase modulated 4x carrier frequency
clock - Drives the RF Carrier
reconstruction D/A and has the AM/
PM correction applied
TTL
Exciter
Controller
PM RF CARR
ANLG
TP5 Phase Modulated RF Carrier -
Reconstructed RF Carrier out of the
D/A and reconstruction filter
1 - 2Vpp
Exciter
Controller
PM RF CARR
TTL
TP6 Phase Modulated RF Carrier TTL -
Digital signal which is the output of the
zero crossing detector. This input to
the detector is the Phase Modulated
RF Carrier Analog.
TTL
Exciter
Controller
CARR ANLG TP7 Carrier Analog - Low pass filtered
input RF Carrier. This can originate
either from the Digital Phase input,
External RF Carrier Input, or the
internal synthesizer.
1 - 2Vpp
Exciter
Controller
CAR TTL TP9 Carrier TTL - This is the multiplexed
signal used as the RF Carrier. The 3
sources are listed above.
TTL
Table 6-2 DAX Testpoint & LED Information Table
(All voltages listed are ±5%)
On Board... Name TP(n)
or
LED
Function, Display
and/or
(Comment) or (Related Potentiometer)
Nominal
Value