Specifications

M.5 Detailed Circuit Description
Refer to the Controller Schematic Diagram (839-7930-021), for
the following discussion.
Refer to other Simplified Diagrams as requested.
NOTE
On all Simplified Diagrams if a bar is placed over the top of the
input or output mnemonics, this designates the function as an
active low signal. When the signal is low, the function is acti-
vated. If no bar is placed over the top of the mnemonic, the func-
tion is an active high signal. When the signal is high, the function
is activated.
NOTE
All inputs/outputs to/from the Controller are fully transient and
overvoltage protected as well as RFI filtered. This is accom-
plished by use of resistor voltage dividers (10k and 100k Ohm),
zener diodes (5.1VDC), and capacitors (.001uF).
M.5.1 LR and OPR PALs
M.5.1.1 Switch Board And External Interface Inputs
From the transmitter front panel Switch board, High, Medium,
Low, Off, and Raise and Lower power level control buttons
provide active high inputs to the Controller on J3-30 through
J3-35. These inputs are buffered by transistor inverters U40 and
U41, and passed to the LR and OPR PAL as active low signals
labeled XXX.IN (example HIGH.IN, MED.IN, etc).
From the External Interface Board, the same extended/remote
control inputs provide active low inputs to the controller on J4-9,
11, 13, 15, 17, and 19. They are enabled by the Local/Remote
Control front panel switch and operate identically to the front
panel switches. These active low signals are paralleled with the
Switch board inputs.
Refer to Figure M-4, LR and OPR PALs.
M.5.1.2 Power Level Selection
When a power level is selected, the corresponding XXX.IN to
the OPR PAL will go low.
Gating logic and a Priority Selector in the OPR PALwill generate
a latched Off, Low, Med, or High logic high output that is sent
to the Lower/Raise (LR) PAL and Local/Remote Transmitter
Status Output transistors.
If multiple XXX.IN inputs go low simultaneously, only a single
OFF, LOW, MED, or HIGH command will be generated (in this
order) as determined by the Priority Encoder.
M.5.1.3 Turn On Request Generation
When the power level selection is made, the high input to the LR
PAL will generate a high Turn On Request (TOR) as long as the
Enable Turn On Request (ENTOR) is high.
The ENTOR comes from the FLT1 PAL, and it must be high for
the LR PAL to generate a TOR.
The TOR is applied to the PWR PAL and the PTIM PAL to begin
the Step Start Sequence.
When the transmitter is manually turned OFF or if the ENTOR
goes low (from a fault condition), the TOR signal goes low and
the transmitter is shut OFF.
M.5.1.4 Local/Remote Transmitter Status Outputs
When the power level selection is made, the corresponding Low
Med or High, logic high output from the OPR PAL will directly
send a high output signal to the Analog Input board via J1-27,
29, or 31. This will activate the Power Control switch on the
Analog Input board that controls the power output.
This logic high signal will also turn on a transistor inverter U42
that sends a low signal to illuminate the lamp inside the pushbut-
ton switch on the Switch board and activates the Remote Status
Output on the External Interface board.
The outputs to the Switch board are on J3-25, 26, and 27. The
outputs to the External Interface are on J5-3, 5, and 7. A conven-
ient place to measure these active low signals are at TP10
(HIGH), TP11 (MED), and TP12 (LOW).
When the transmitter is OFF, an inverter transistor pulls TP13 low
and this signal is sent to the External Interface board via J5-1.
M.5.1.5 Lower/Raise Fine Power Control
After Enable 3 has been generated by the PWR PAL, and as long
as the Keypress is low, the LOWER.IN and RAISE.IN inputs to
the LR PALare active. The Priority Select circuit givesthe Lower
command priority over the Raise command if both inputs are low
atthesametime.
The active logic high LOWER output is sent to the Analog Input
board via J1-1 to control the Fine Power Control PALs. A transistor
inverter U41 pulls TP15 and J3-29 low, which illuminates the lamp
inside the pushbutton switch on the Switch board.
The same action occurs for the RAISE output at J1-15, and
TP14/J3-28. A transistor inverter U41 pulls TP14 and J3-28 low,
which illuminates the lamp inside the pushbutton switch on the
Switch board.
M.5.1.6 VSWR Self Test Request
When the transmitter is first turned ON, or the selected power
level is changed, or when the Manual VSWR Self Test switch S5
is depressed, the Detect Any Change circuit in the LR PAL
generates a VSWR Self Test (VST).
The VST output at U6-18 will go high for 8mS. This turns on Q1
and J7-9 VSWR Self Test Request goes low. This low signal is
sent to the Output Monitor for testing the VSWR detectors via
the Transmitter Interface. The results of the test are determined
on the Output Monitor.
The VSWR Self Test can also be activated by the VSWR Test
switch on the Control front panel, which is connected to J2-11
on the Controller.
M.5.1.7 Keypress
Anytime a XXX.IN input is low or if the transmitter is in the
process of an A/C Restart, the Keypress - A/C Restart Detector
inside the OPR PAL will generate a high Keypress signal. This
signal is connected to the LR PAL and inhibits any Raise or
Lower command input.
M.5.1.8 Fault Input
If the FLT line Master Reset from the FLT1 PAL goes high, the
Priority Select circuit on the OPR PAL is reset and the Operator
888-2339-002 M-3
WARNING: Disconnect primary power prior to servicing.