Specifications

The outputs will remain in this state, until the FOVR input goes
back high. When the input does go back high, the OV1 output
will go high.
When both OV0 and OV1 outputs are high, the 160mS Overload
Restart Timer is started and 160mS later the TOV output will go
high for 250 uS.
The OV0 and OV1 outputs will go back low, and the Mute
Request and ENTOR lines will go high. This will generate a new
TOR and the transmitter will return to operation.
After 5.6 seconds, a high UNFLT pulse from the PTIM PAL is
sent to the FLT 1 PAL.
If another FOVR fault occurs within this time, the FLT 1 PAL
will upgrade it to an FOFF Fault.
If another FOVR fault occurs after this time, the FLT 1 PAL will
respond to it as another FOVR Fault.
An FOVR will co-exist with an in progress FACR, each will
recover according to its own timing and requirements.
M.5.8.3 Other Overload Faults
There are two types of special Overload Faults.
DRIVER UNDERDRIVE FAULT DR.UD.X
(LOW DRIVE)
RELAY K2 FAULT K2OV
The DR.UD.X input at J6-13 will occur anytime RF Drive to the
Big Step and Binary RF Amplifiers is reduced to less than 80%
of normal. If the offending fault was created in the RF Chain,
the Control front panel should indicate the location.
The K2OV Fault from the PWR PAL input announces main
contactor dropout at inappropriate times, and is designed to
protect the step-start system. There is no status indication for
this fault.
Both are recognized after ENBL2 is generated by the PWR PAL.
If either fault input goes low, the ENTOR output is removed and
then returned 160mS after a TOV pulse.
If the fault is still present after Enable 2 is generated on the retry,
theFLT1PALwillupgradeittoanFOFFFault.
M.5.8.4 OFF Fault Handling
Fault OFF triggers an immediate, non-recovering, shutdown of
the transmitter by generating a Mute Request and canceling the
ENTOR signal.
The OFF Fault Handling asserts the FLT line to asynchronously
clear all PAL state machines.
The transmitter must be manually restarted after the fault has
been corrected.
An FOFF will override an in progress FOVR or FACR.
M.5.8.5 Foldback Limit
The FBLIM input from the FLDBK PAL indicates maximum
Foldback has been reached.
When this input goes high, it becomes an FOFF Fault.
M.5.8.6 LED Enable
The LEDEN output controls enabling of the Fault LED Latching
circuits and therefore the Control front panel indicator LEDs.
KLVX Supply Low Voltage Sensing and C.UL Controller Un-
regulated Loss provide status of low voltage supplies. Both must
be high for these indicators to be illuminated.
Should either input go low, the LEDEN output will go high and the
indicators are turned off to conserve battery backup voltage.
M.5.9
PAL Fault Indicators
Bicolor indicators DS1, DS2, DS3, and DS4 are controlled by
U14 and provide a visual status indication for their designated
PAL s.
When the LEDINH (LED Inhibit) output from U36-2 is low, the
indicators are active.
GREEN illumination indicates normal operation, RED illumi-
nation indicates a internal fault condition.
Refer to each individual PAL for the more specific information.
When a Controller Unregulated Loss is detected, The LED
Inhibit line will be high and the indicators are turned off to
conserve battery backup voltage.
M.5.10
Clock Generator
The 8 kHz master clock is generated by a 555 timer U20 running
in an astable configuration. This clock is divided down by a
string of synchronous dividers U15 through U19. Six different
clock frequencies are generated and distributed, most of which
can be measured on TP4 though TP8.
M.5.11
LATCH PALs
Most of the faults to which the Controller has responded, except
the RF MUTE and VSWR Test, are latched by the three LATCH
PALs U11, U12, and U13.
Refer to Figure M-9, LATCH PAL.
Each of the three LATCH PALs has exactly the same internal circuits.
They contain 10 fault inputs, 10 latches, and 10 alarm outputs.
After the Enable input is high, if the fault input to the PAL is or
goes low, the Alarm output will go low and remain in that state
until the Reset input goes high.
U12 is connected to Enable 1, U11 is connected to Enable 2, and
U13 is connected to Enable 3, and the Reset is connected to pin
13. LATCH PAL alarm outputs are connected to the Fault LED
Latching inputs.
M.5.12
Other Latches
U26 and U33 function in a manner similar to the LATCH PALs,
except that they use diode steering logic to accomplish this task
and are always enabled by FCLK0.
When the input of U26 goes low, the output of U33 goes low.
The input of U26 is then held low to +.6VDC by the diode drop,
and the output of U33 remains low.
It is not possible for the output of U33 to go back high until the
Reset input is high.
888-2339-002 M-9
WARNING: Disconnect primary power prior to servicing.