Attachment 6 Current IF Monopulse Receiver Alignment Procedures.pdf

Attachment 12 Current IF Monopulse Receiver Alignment Procedures

The following procedures are from the Mode S Technical Instruction Book 6365.7A. The procedures and diagrams are for reference purposes to show how the current IF Monopulse Receiver interfaces with other components. It is not a requirement that the replacement IF Monopulse Receiver have the same physical form or follow the same alignment procedures.

The current IF Monopulse Receiver gain and offset adjustments are difficult to use and located at inaccessible areas. It is highly recommended that the replacement IF Monopulse Receiver has easier to use and more accessible adjustments.

TI 6365.7A

INSTRUCTION BOOK

MODE SELECT BEACON SYSTEM (MODE S) SENSOR

RECEIVER/RF TEST TARGET GENERATOR

P/O INTERROGATOR TYPE FA- 10202

SERIAL NO. 1-148

12/09/2010

U. S. Department of Transportation

Federal Aviation Administration

National Airways Systems Engineering

William J. Hughes Technical Center

Atlantic City International Airport, New Jersey 08405

12/09/2010 TI 6365.7A

1.2.2.5 IF Monopulse Receiver A5. Figure 1-6, IF Monopulse Receiver A5, converts the IF replies received on the Σ, ∆, and Ω receive channels to analog video signals. The IF monopulse receiver also processes the Σ and ∆ IF signals to generate a monopulse video signal. The monopulse video signal indicates the off-boresight location (in azimuth) of the aircraft. The video signals are sent to video processor/monitor A3. The IF monopulse receiver is mounted on the left interior wall of the interrogator cabinet below the RF receiver. The unit is approximately 21 inches high, 16 inches wide, 3 inches deep, and weighs 14.2 pounds. The IF monopulse receiver rests on mounting studs and is secured to the back wall by four captive screws. Two handles are provided to aid in removing the unit from its mounting studs. Holes in the unit cover provide access to components for onsite adjustment. Twelve I/O connectors (ten coaxial and two multipin D-types) allow the IF monopulse receiver to interface with the rest of the receiver/RFTTG LRUs. The IF monopulse receiver operates on 120V AC, +15V DC and -15V DC power provided by the interrogator cabinet power supplies. The IF monopulse receiver is cooled by air circulated through the interrogator cabinet.

FIGURE 1-6. IF MONOPULSE RECEIVER A5

1-9

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7.4.3 IF Monopulse Receiver A5 Removal.

This procedure is used to remove IF monopulse receiver A5.

Prerequisite Procedures

Connect the local terminal and obtain control of the Mode S sensor per section 3.0 of TI 6365.5.

Tools and Test Equipment Required

Screwdriver, flat-tip, heavy-duty

Screwdriver, flat-tip, light-duty (short)

Wrench, open-end 5/16-inch

Removal Procedure

See Figure 7-9, IF Monopulse Receiver A5 Removal and Installation

1. At interrogator cabinet control panel A1 (10), set MAIN POWER circuit breaker CB1 to

OFF. Audible alarm makes a loud sound.

2. At interrogator control panel A1 (10), set BRKR ALARM circuit breaker CB2 to OFF to silence alarm.

3. Open door to interrogator. (If necessary, then refer to TI 6365.5, Section 7.0, Preparation of

Interrogator Cabinet Prior to Maintenance.)

4. Open the swingout rack to gain access to the IF monopulse receiver.

CAUTION: When disconnecting SMA connectors, be sure to rotate the connector coupling nut only. Rotating the connector body will cause the connector to break loose from the cable.

5. Disconnect the RF cables from the top connectors J1 through J7 (1).

6. Disconnect the RF cables from the bottom connectors J8 (8), J9 (6), and J11 (4).

7. Loosen the two connector screws and disconnect the electrical plug from connector J15 (7).

8. Loosen the two connector screws and disconnect the cable from connector J10 (5).

9. Completely loosen the four captive screws (9) that secure the unit to the cabinet wall.

WARNING: IF monopulse receiver A5 weighs approximately 14 pounds and is at an awkward angle for removal. To avoid injury, use care when removing.

10. Grasp handles (3) and slide IF monopulse receiver up until large holes in the mounting slots (2) clear the mounting pins on the cabinet wall.

11. Remove IF monopulse receiver.

12. Pack IF monopulse receiver for shipping per Paragraph 7.7.

Drag the side handles to change the width of the text block.

FIGURE 7-9. IF MONOPULSE RECEIVER A5 REMOVAL AND INSTALLATION

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7.4.4 IF Monopulse Receiver A5 Installation.

This procedure is used to install IF monopulse receiver A5.

Prerequisite Procedures

Unpack IF monopulse receiver A5 per Paragraph 7.7.

Tools and Test Equipment Required

Screwdriver, flat-tip, heavy-duty

Screwdriver, flat-tip, light-duty (short)

Wrench, open-end 5/16-inch

Torque wrench, SMA connector, 5/16–inch

Installation Procedure

See Figure 7-9, IF Monopulse Receiver A5 Removal and Installation.

1. Ensure that the power to the interrogator cabinet is still off.

WARNING: IF monopulse receiver A5 weighs approximately 14 pounds and is installed at an awkward angle. To avoid injury, use care when installing.

2. Grasp handles (3) and position mounting slots (2) over mounting pins on cabinet wall.

3. Lower IF monopulse receiver onto mounting pins until unit is resting on pins.

4. Tighten four captive screws (9) to secure IF monopulse receiver to cabinet wall.

CAUTION: When connecting SMA connectors, be sure to rotate only the connector coupling nut. Rotating the connector body will cause the connector to break loose from the cable.

5. Connect 10 loose RF cables to their respective connectors J1 through J7 (1), J8 (8), J9

(6), and J11 (4). Using the SMA torque wrench, tighten the RF cables to preset the value of the wrench (8 inch-pounds).

6. Connect two loose electrical plugs to their respective connectors J10 (5) and J15 (7).

Tighten connector hold-down screws at each plug.

7. At interrogator control panel A1 (10), set BRKR ALARM circuit breaker CB2 to ON.

8. At interrogator control panel A1 (10), set MAIN POWER circuit breaker CB1 to ON.

Audible alarm turns off.

9. Perform required receiver alignment procedures per Paragraph 7.5.

10. Close swingout rack and interrogator cabinet doors. (If necessary, refer to TI 6365.5, section 7, Securing Interrogator Cabinet After Maintenance.)

11. Check out interrogator per section 6 of TI 6365.5.

04/26/2013 SDR-MODES-003

7-89

Table 7-8 Alignment Procedure Requirements

LRU Replaced

Alignment procedure Required

Handbook Procedure

165 7.5.2

7.5.3

- OR -

7.5.4 7.5.5 7.5.6 7.5.7 7.5.8 7.5.9

Handbook Procedure 169 Recalibration

Handbook Procedure 169 Full Calibration

A3 Video Proc/Monitor ●

A5 IF Monopulse Receiver ● ● ● ●

A6 Omni Diplexer ●

A9 Local Oscillator ● ●

A14 RFTTG ● ● ● ● ● ●

A19 Monopulse Diplexer ● ● ● ● ● ● ● ●

A20 RF Receiver ● ● ● ●

W22 and W23 ● ● ● ● ● ● ●

W25 and W26 ● ● ● ● ● ●

W30 and W31 ● ● ● ● ● ●

W38 and W39 ● ● ● ●

W64 and W65 or W77 and W78 ● ● ● ● ● ● ● ●

W94 and W95 ● ● ● ● ● ● ● ●

9S2 or 9S3 ● ● ● ● ● ● ● ●

Rotary Joint ● ● ● ● ● ● ● ● Sigma, Delta and Omega Cables between Rotary Joint and The Antenna

Beacon Antenna ●

7.5.2 Sigma and Delta Channel Phase Alignment

7.5.3 Test Target Amplitude and Phase Alignment

Network Analyzer

7.5.4 Test Target Amplitude and Phase Alignment CABLE LEGEND

Using The Network Analyzer and Average Power Meter W22 and W23 From inside interrogator to Monopulse Diplexer

7.5.5 RF Receiver STALO Signal Phase Alignment W25 and W26 From Diplexer to RF Receiver

7.5.6 IF Monopulse Receiver Detector Adjustment W30 and W31 To/From Diplexer to RFTTG

7.5.7 Log Slope and Gain Using a Low Power Variable 50dB Attenuator W38 and W39 From the RF Receiver To The IF Receiver

7.5.8 Probability of Detection Thresholds W64 and W65 From the Transfer Switch To Channel A Interrogator

7.5.9 Power Detector Calibration W77 and W78 From the Transfer Switch To Channel B Interrogator Handbook Procedure 169 Recalibration W94 and W95 From Bottom of Rotary Joint To RF Transfer Switch

Handbook Procedure 169 Full Calibration 9S2 or 9S3 Sigma and Delta RF Transfer Switches

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7.5.5 Radio Frequency (RF) Receiver Stabilized Local Oscillator (Stalo) Signal Phase

Alignment Procedure.

This procedure will be used to align the phase of the local oscillator signal used in the RF receiver mixing circuits in accordance with Table 7-8 or a “out of tolerance” condition has been determined. Delta phase will be 79 degrees out of phase with Sigma at completion.

For this procedure a model HP 8753C Network Analyzer will be used for measuring the Stalo

Phase. The S-Parameter test set will not be required. It is important to have the interconnect cable between both units disconnected.

Prerequisite Procedures

1. One Mode S certified technician will be required to perform this procedure.

2. This procedure will require approximately 30 minutes to complete. Time requirements are site dependent based on factors such as experience level, procedure familiarity, and advanced preparation

3. This procedure will be performed on the STANDBY channel in the Mode S mode of operation or the STANDBY or OFFLINE channel in the ATCBI mode of operation.

4. In accordance with existing procedures coordination with the appropriate personnel for release of local terminal control and, if necessary, channel changes may be required.

Tools and Equipment Required

Network Analyzer – HP 8753C

Adapter, SMA jack-to-N jack

Adapter, SMA plug-to-N jack

Cable, RG214 coax with N plugs, 10-feet long, (2)

5/16 8 inch/pounds, SNA Torque Wrench

Procedure

1. Set up the Mode S as follows:

a. Contact the appropriate personnel for release of control of the local terminal.

b. Ensure that the channel to be checked is in the STANDBY Mode S mode of operation or the STANDBY or OFFLINE ATCBI mode of operation.

c. If necessary, then coordinate with appropriate personnel to make a channel change.

NOTE: If performing this procedure in the Mode S mode of operation, then begin with step (2). If performing this procedure in the ATCBI mode of operation then skip to step

(3).

2. If this procedure is to be performed in the Mode S Mode of operation, then ensure that the KCRT is connected to the STANDBY Interrogator.

a. From the LMT, disable automatic channel switching from the ONLINE channel as follows.

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(1) From the LMT main screen, use the Tog (Toggle) Chan and Tog Port to select the correct channel and port to communicate with the ONLINE channel to disable automatic switching.

(2) From the LMT main screen, select the Sensor Commands menu.

(3) Open the Sensor Control menu.

(4) Open the Sensor Channel menu

(5) Double click on Disable Automatic to disable automatic switching.

(6) Close the Sensor Commands screen.

NOTE: Under the Auto Switching section of the LMT main screen observe DISABLED in red indicated in the Sensor Channel window.

b. From the KCRT connected to the STANDBY channel, disable automatic testing as follows:

From the Mode S Main Menu, type: 7 <CR> to disable automatic testing. Ensure “Auto Testing Suspended” is displayed at the top of the KCRT display.

c. Skip to step 4.

3. If this procedure is to be performed in the ATCBI Mode of operation, then ensure that KCRT is connected to the STANDBY Interrogator.

a. Turn off the DPS of the channel you wish to evaluate.

b. Select: 2<CR>, Standby KCRT Bit, to proceed to the Mode S Main Menu.

4. Generate a Continuous Wave Boresite test target as follows:

a. From the KCRT Mode S Main Menu, type: 6 <CR> to select Calibration Sub

Menu.

b. From the Calibration Submenu, type: 1 <CR> to generate Cont Wave

Boresight.

5. Turn on the network analyzer and allow it to warm up for 5 MIN. Connect

Network Analyzer for measurement and/or adjustment of the Stalo Phase as follows. See

Figure 7-29, Setup for Stalo Phase, and Figure 7-30, If Monopulse Receiver.

a. On IF monopulse receiver (A5), disconnect termination AT3 from connector

J18.

7-125

J4

J18 J17 J16

W40 W39 W38

W81

RF RECEIVER

A20

IF MONOPULSE

RECEIVER

A5

LOCAL

OSCILLATOR

A9

RF OUT R A B

PORT 1 PORT 2

RF IN AR B

NOTE: Network Analyzer to S-Parameter Test Set interconnect cable on back of test sets must be

DISCONNECTED between both units.

FIGURE 7-29. SETUP FOR STALO PHASE

b. Using an N jack-to-SMA plug adapter, connect test cable 1 (RG214 coax with N plugs, 10-feet long) from PORT A of the Network Analyzer to J18 (SIGMA) on the IF monopulse receiver. See Figure 7-29, Setup for Stalo Phase.

c. Disconnect cable W40 from the J4 connector on the IF monopulse receiver. See Figure 1, Setup for Stalo Phase.

d. Using an N jack-to-SMA jack adapter, connect test cable 2 (RG214 coax with N plugs, 10-feet long) from the Network Analyzer port B to cable W40 removed from connector J4 on the IF Monopulse Receiver (A3). See Figure 7-29, Setup for Stalo Phase.

7-126

7-127

6. Set up the Network Analyzer as follows:

a. Ensure that the interconnect cable between the Network Analyzer and the S-parameter test set is disconnected.

b. Press PRESET to get the Network Analyzer in a known configuration.

c. Under the STIMULUS section of the Network Analyzer:

Press: MENU

Select: CW FREQ

Type: 60 and press M/u

Select: POWER

Type: -10 and press X1

d. Under the RESPONSE section of the network analyzer:

Press: Format

Select: Log Magnitude

Press: MKR.

Select: Marker 1

e. Under the ENTRY section of the network analyzer:

Press: ENTRY OFF

f. Under the response section of the Network Analyzer

Press: MEAS

Select: R, "Marker 1" should read -6 ± 3 dBm.

Select: A, "Marker 1" should read -46 ± 3 dBm.

Select: B, "Marker 1" should read -10 ± 3 dBm.

Select: A/B, "Marker 1" should read -36 ± 3 dBm.

Press: FORMAT

Select: PHASE

Press: AVG

Select: AVERGING ON

Press: SCALE REF

Select: MARKER����REFERENCE

Press: MKR

Select: MKR ZERO

g. Under the ENTRY section of the network analyzer:

Press: ENTRY OFF

7. Perform Delta phase adjustment as follows:

7-128

a. At IF monopulse receiver (A5), disconnect termination AT2 from connector

J17.

b. Move test cable 1 from J18 (SIGMA) to J17 (DELTA).

c. Reconnect termination AT3 to jack J18 (SIGMA).

d. On network analyzer display, note reading of delta channel local oscillator phase. Marker 1 should read 79 ± 0.5 degrees. If necessary, then unlock and adjust A20Z2

(DELTA PHASE ADJUST) on RF receiver A20 until phase reading is 79 ± 0.5 degrees. To unlock Z2, loosen locking nut located just behind the adjustment knob. See figure 7-31, RF

Receiver (A20) Phase Adjustments. If a phase adjustment cannot be acquired by adjustment of the Z2 (DELTA PHASE ADJUST), then proceed to step (8). If an adjustment of 79 +- 0.5 has been acquired, then proceed to step (10).

8. Perform steps (8) and (9) only if the DELTA Phase was not acquired as indicated in the previous step. On the Network Analyzer, set up the phase marker for a

DELTA zero reference signal as follows:

Press: SCALE REF

Select: MARKER����REFERENCE

Press: MKR

Select: MKR ZERO REF = ∆, “Marker 1” should read less than .25 degrees

9. Perform SIGMA phase adjustment as follows:

a. On IF monopulse receiver, disconnect termination AT3 from connector J18

(SIGMA).

b. Move test cable 1 from J17 (DELTA) to J18 (SIGMA).

c. Reconnect termination AT2 to jack J17 (DELTA).

d. On network analyzer display, note reading of delta channel local oscillator phase. Marker 1 should read -79 ± 0.5 degrees. If necessary, then unlock and adjust A20Z1

(SIGMA PHASE ADJUST) on RF receiver A20 until phase reading is -79 ± 0.5 degrees. To unlock Z1, loosen locking nut located just behind the adjustment knob. See figure 7-31, RF

Receiver (A20) Phase Adjustments.

10. Disconnect test equipment and restore interrogator cabling to original configuration.

11. Disable the continuous wave boresite test targets as follows:

At the KCRT, Press: <esc>, to disable the continuous wave boresite test targets.

NOTE: If continuing forward with additional receiver alignments you can skip to the appropriate procedure and step at this time. This is to avoid enabling and disabling of the

“auto testing” and “auto switching” functions or the turning on and off the DPS.

12. Restore the Mode S sensor as follows:

7-129

NOTE: If performing this procedure in the STANDBY Mode S mode of operation, then proceed to the following step (13). If performing this procedure in the ATCBI mode of operation, then skip to step (14).

13. If this procedure is being performed in the Mode S mode of operation, then restore as follows:

a. Enable automatic testing as follows:

(1) From the Mode S Calibration Menu, Press <$>, to return to the Mode S Main

Menu.

(2) From the Mode S Main Menu, type: 7 <CR>, to enable automatic testing.

b. From the LMT, enable automatic channel switching as follows:

(1) From the LMT main screen, select the Sensor Commands menu.

(2) Open the Sensor Control menu.

(3) Open the Sensor Channel menu.

(4) Double click on Enable Automatic, to enable automatic switching.

(5) Close the Sensor Commands screen.

NOTE: Under the Auto Switching section of the LMT main screen, observe ENABLED in green indicated in the Sensor Channel window.

c. Skip to step (15).

14. If this procedure is being performed in the ATCBI mode of operation, then restore the Mode S as follows:

Turn on the corresponding DPS and press the RESET button.

NOTE: In some cases in which the DPS has been turned off for an extended period of time, the interrogator will stop trying to communicate with the DPS. In this case, after the DPS has been turned on, the interrogator channel will not return to a STANDBY condition. If this becomes the case, then you will need to turn off the STANDBY interrogator for approximately twenty seconds, then turn it back on and press the reset button on the corresponding DPS.

15. RFTTG amplitude and phase alignment is complete.

7-130

FIGURE 7-31. RF RECEIVER (A20) OF PHASE ADJUSTMENTS

7.5.6 Intermediate Frequency (IF) Monopulse Receiver Detector Adjustment.

This procedure is to be used to adjust the gain and DC offset of the monopulse detector. This procedure is to be used after replacement of the IF monopulse receiver or an “out of tolerance” condition has been determined.

Prerequisite Procedures

1. One Mode S certified specialist will be required to perform this procedure.

2. This procedure will require approximately 30 minutes to complete. Time requirements are site dependent based on factors such as experience level, procedure familiarity, and advanced preparation

3. This procedure will be performed on the STANDBY channel with the Mode S sensor in the Mode S mode of operation or the STANDBY or OFFLINE channel with the Mode S sensor in the ATCBI mode of operation.

4. In accordance with existing procedures coordination with the appropriate personnel for release of the local terminal control and channel changes may be required.

Tools and Test Equipment Required

Alignment tool (Tweaker)

KCRT

7-131

Procedure

1. Set up the Mode S as follows:

a. Contact the appropriate personnel for release of control of the local terminal.

b. Ensure that the channel to be checked is in the STANDBY Mode S mode of operation or STANDBY or OFFLINE ATCBI mode of operation.

c. If necessary, then coordinate with appropriate personnel to make a channel change.

NOTE: If performing this procedure in the Mode S Mode of operation, then begin with the following step (2). If performing this procedure in the ATCBI mode of operation then skip to step (3).

2. If this procedure is to be performed in the Mode S Mode of operation, then ensure that the KCRT is connected to the STANDBY Interrogator.

a. From the LMT disable automatic channel switching from the ONLINE channel as follows:

(1) From the LMT main screen, use the Tog (Toggle) Chan and Tog Port to select the correct channel and port to communicate with the ONLINE channel to disable automatic switching.

(2) From the LMT main screen, select the Sensor Commands menu.

(3) Open the Sensor Control menu.

(4) Open the Sensor Channel menu

(5) Double click on Disable Automatic, to disable automatic switching.

(6) Close the Sensor Commands screen.

NOTE: Under the Auto Switching section of the LMT main screen, observe DISABLED in red indicated in the Sensor Channel window.

b. From the KCRT connected to the STANDBY channel, disable automatic testing as follows:

From the Mode S Main Menu, type: 7 <CR> to disable automatic testing.

Ensure “Auto Testing Suspended” is displayed at the top of the KCRT display.

c. Skip to step 4.

3. If this procedure is to be performed in the ATCBI Mode of operation, then ensure that KCRT is connected to the Interrogator.

a. Turn off the STANDBY DPS of the channel you wish to evaluate.

b. On the KCRT, Select: 2 <CR> Standby KCRT Bit, to proceed to the Mode S

Main Menu.

4. Perform phase detector alignment (Monopulse Values) as follows:

Menu.

a. From the Mode S Main Menu, type: 6 <CR> to select the Calibration Sub

b. From the Calibration Sub Menu, type: 6 <CR> to select “Phase Detector Alignment (Monopulse Values).”

c. At KCRT, observe BORESIGHT, CROSSOVER, and DIFFERENCE values displayed.

d. At the IF monopulse receiver, A5, adjust A1R18 (MONOPULSE GAIN) for a DIFFERENCE reading of 86 ± 0.5.

e. On monopulse receiver A5, adjust A1R12 (MONOPULSE OFFSET) to establish a BORESIGHT reading of 128 ± 0.5 and a CROSSOVER reading of 42 ± 0.5. If necessary, then readjust A1R18 to maintain a DIFFERENCE reading of 86 ± 0.5. See Figure 7-32 Phase Detector Adjustment Locations

NOTE: Once the proper values have been acquired, it is a good practice to close the interrogator door and allow the IF Monopulse receiver to warm up to normal operating temperature (Approximately 10 minutes). The values may change slightly during this period.

If they do, go back to alignment process and readjust as needed.

5. Once the monopulse values are consistent on the KCRT display press: <$> to stop the Phase Detector Alignment (Monopulse Values) process.

7-132

7-133

NOTE: If continuing forward with additional receiver alignments you can skip to the appropriate procedure and step at this time. This is to avoid enabling and disabling of the

“auto testing” and “auto switching” functions or the turning on and off the DPS.

6. Restore the Mode S sensor as follows:

NOTE: If performing this procedure in the STANDBY Mode S mode of operation, then proceed to the following step (7). If performing this procedure in the STANDBY or

OFFLINE ATCBI mode of operation, then skip to step (8).

7. If this procedure is being performed in the STANDBY Mode S Mode of operation, then restore the Mode S as follows:

a. Enable automatic testing as follows:

At the KCRT Mode S Main Menu, type: 7 <CR> to enable automatic testing.

b. From the LMT, enable automatic channel switching as follows:

(1) From the LMT main screen, select the Sensor Commands menu.

(2) Open the Sensor Control menu.

(3) Open the Sensor Channel menu.

(4) Double click on Enable Automatic, to enable automatic switching.

(5) Close the Sensor Commands screen.

NOTE: Under the Auto Switching section of the Mode S main screen, observe ENABLED in green indicated in the Sensor Channel window.

c. Skip to step (9).

8. If this procedure is being performed in the ATCBI Mode of operation, restore the

Mode S as follows:

Turn on the DPS and press the RESET button.

NOTE: In cases in which the DPS has been turned off for an extended period of time the interrogator will stop trying to communicate with the DPS. In this case, after the DPS has been turned, on the interrogator channel will not return to a STANDBY condition. If this becomes the case, then you will need to turn off the STANDBY interrogator for approximately twenty seconds, then turn it back on and press the reset button on the corresponding DPS.

9. Monopulse detector alignments are complete.

7.5.7 Procedure for Log Slope And Gain Alignment Using a Low Power Variable Attenuator.

This procedure provides for the alignment of the Sigma, Aux, Delta, and Omega log slopes and gains of the log amplifiers. These procedures are performed after replacement of an LRU, as indicated by the LRU replacement and associated alignment chart, or an out of tolerance condition has been detected.

Prerequisite Procedures

7-134

1. One Mode S certified specialist will be required to perform this procedure.

2. This procedure will require approximately one hour per channel to complete. Time requirements are site dependent based on factors such as experience level, procedure familiarity, and advanced preparation

3. This procedure will be performed on the STANDBY channel with the Mode S sensor in the Mode S Mode of operation or the STANDBY or OFFLINE channel with the Mode S sensor in the ATCBI Mode of operation.

4. In accordance with existing procedures, coordination with the appropriate personnel for release of the local terminal control will be required.

5. SAP changes and, if necessary, channel changes and/or mode of operation may be required.

Tools and Test Equipment Required

Variable 0 – 70db low power attenuator (or Equivalent) NSN # 5985-01-365-7690

Oscilloscope

Digital Voltage Multimeter (DVM)

RG-214 cable or Equivalent

Adapter, N-type to SMA

Alignment tool (Tweeker)

Torque wrench, (SMA)

Detailed Procedure.

Procedure

NOTE: If the Mode-S SAP VSP_TABLE->atcr_stc_crv_ref is set greater than 49dB, then prior to starting this alignment that SAP must be lowered to 43. The value must be changed so that STC will not affect the following alignment. The SAPs on the channel being aligned must be temporarily installed. After alignment is completed, the

SAP must be set back to its operational value.

1. Set up the Mode S as follows:

a. Contact the appropriate personnel for release of control of the local terminal.

b. Ensue that the channel to be checked is in Mode S mode of operation or ATCBI mode of operation.

c. If necessary, then coordinate with appropriate personnel to make a channel change.

NOTE: If performing this procedure in the STANDBY Mode S mode of operation, then begin with step (2). If performing this procedure in the STANDBY or OFFLINE ATCBI mode of operation, then skip to step (3).

2. If this procedure is to be performed in the Mode S Mode of operation, then ensure

7-135 that the KCRT is connected to the STANDBY Interrogator.

a. From the LMT disable automatic channel switching from the ONLINE channel as follows.

(1) From the LMT main screen, use the Tog (Toggle) Chan and Tog Port to select the correct channel and port to communicate with. Ensure configuration communicating with the

ONLINE channel to disable automatic switching.

(2) From the Mode S main screen, select the Sensor Commands menu.

(3) Open the Sensor Control menu.

(4) Open the Sensor Channel menu

(5) Double click on Disable Automatic, to disable automatic switching.

(6) Close the Sensor Commands screen.

NOTE: Under the Auto Switching section of the Mode S main, observe DISABLED in red indicated in the Sensor Channel window.

b. From the KCRT connected to the STANDBY channel, disable automatic testing as follows:

From the Mode S Main Menu, type: 7 <CR> to disable automatic testing.

Ensure “Auto Testing Suspended” is displayed at the top of the KCRT display.

c. Skip to step 4.

3. If this procedure is to be performed in the ATCBI Mode of operation, then ensure that KCRT is connected to the corresponding Interrogator.

a. Turn off the DPS of the channel you wish to evaluate.

b. Select: 2 <CR>, Standby KCRT Bit, to proceed to the Mode S Main Menu.

4. Perform the RFTTG Output Verification as follows:

a. From the KCRT Mode S Main Menu, Select: 6 <CR> to proceed to the CALIBRATION SUB MENU.

b. From the MODE S CALIBRATION MENU, Select: 8 <CR> to proceed to the LOG AMP ALIGNMENT

c. From the Log Amp Alignment Menu, Select: 1 <CR> CHECK WAVESHAPE OF THE RF/TTG OUTPUT.

d. At the Video Processor Monitor (VPM), attach an oscilloscope probe to the

Log Sigma Video test point at A3-TP2 and the ground to A3-TP3. See Figure 7-34, A3 -

Video Processor Monitor (VPM) Test Points.

12/09/2012 TI 6365.7A

7-136

A3 – VIDEO PROCESSOR

MONITOR

FIGURE 7-33. A3 - VIDEO PROCESSOR MONITOR (VPM) TEST POINTS

e. From the KCRT, press: <CR> to initiate a pulse train of 15 pulses to be displayed on the oscilloscope.

f. Set up the oscilloscope in such a way for best viewing of the pulse train to permit an accurate measurement of the amplitudes. This will require that the vertical position and volts/division controls on the oscilloscope be changed to use the maximum scope gain allowed that will permit the top of the SUM pulses to remain on the scope display. Measure the voltage difference across the top of the SUM pulse amplitudes. Ensure that any amplitude difference does not exceed 25mV. See figure 2, Measurement of SUM and DELTA Pulse

Amplitudes.

NOTE: When measuring the SUM and DELTA pulse amplitudes typically, a defective

RFTTG will have the first two or three pulses attenuated from the other pulses. If this is found to be the case, then replacement of the RFTTG will be necessary.

g. At the VPM, attach the oscilloscope probe to the Log Delta Video test point

A3-TP8 and the ground to A3-TP3. See figure 7-33, A3 - Video Processor Monitor (VPM)

Test Points.

h. Measure the voltage difference across the top of the DELTA pulse amplitudes.

Ensure that the difference does not exceed 25mV. See figure 7-34, Measurement of SUM and

DELTA Pulse Amplitudes.

FIGURE 7-34. MEASUREMENT OF SUM AND DELTA PULSE AMPLITUDES

i. From the KCRT, press: $ to stop procedure and return to the Log Alignment

Menu.

5. Perform the zero baseline adjustment as follows:

a. From the Log Alignment Menu, select: 3 <CR> to enter the Log Gain and

Noise Adjustments.

b. Enter the number that corresponds to the model number of the KCRT being used with this procedure and press <CR>.

c. From the Log Gain and Noise Adjustments Menu, select: 9 <CR> to select

All Tests. This will initiate test pulses and update all the Log Amp Gains and Noise levels continuously so appropriate adjustments can be made to the baseline offsets.

d. At the VPM, use a Digital Voltmeter (DVM) to measure the individual D.C.

baseline levels with respect to ground (A3 TP3). See figure 7-33, A3 – Video Processor

Monitor (VPM) Test Points, for the location of test points. Utilizing the appropriate offset adjustment set the Sum, Delta, Omni, and Aux Log Video Noise signals as read on the DVM to 0 Volts DC.

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e. Once all 0 Volt DC baseline levels have been attained, at the KCRT:

(1) Press: $, to stop the sampling process.

(2) Press: $, to exit back to the Log Alignment Menu.

6. Setup for Log Slope adjustments as follows:

a. From the KCRT at the Log Alignment Menu, select: 2 <CR>, to enter the Log Slope Adjustments.

b. In the Mode S interrogator to be aligned disconnect the following cables. See Figure 7-36, RF Receiver (A20) cables W25, W26, W27 connections and Figure 7-37, Diplexer (A19) cable W30 connection.

(1) Sigma input to RF Receiver, cable W25 at connection A20HY1J2.

(2) Delta input to RF Receiver, cable W26 at connection A20HY1J1.

(3) Omega input to RF Receiver, cable W27 at connection A20A1J8.

(4) Test Target Source, cable W30 at connection A19DC1J4.

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FIGURE 7-36. RF RECEIVER (A20) CABLES W25, W26, W27 CONNECTIONS.

FIGURE 7-37. DIPLEXER (A19) CABLE W30 CONNECTION

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c. Using a 50-Ohm variable attenuator (NSN # 5985-01-365-7690) set the attenuator to a 50 dB level and measure its value to determine its exact value to 0.1 dB accuracy. Enter this measured value into the space provided on the KCRT and Press: <CR> to enter the value.

d. Select: <CR>, to continue to the Select Channel to Align Menu.

7. Perform Log Sigma Slope adjustments.

a. From the KCRT, select: 1 <CR> to select the Sigma channel to be adjusted.

b. Place the variable attenuator in series with W30. With a short piece of RG223, connect the output of the attenuator directly to A20HY1J2, the Sigma Channel input to the RF

RCVR. Set the attenuator level to 0 dB. See Figure 7-36, RF Receiver (A20) cables W25, W26, W27 connections, Figure 5, Diplexer (A19) cable W30 connection and Figure 7-38, Log

Slope Measurement using variable attenuator.

c. Select: <CR>, to initiate the High Level Log Slope Sampling Process.

d. For accuracy, let the program sample long enough to attain a stable High Level value. When a stable value has been attained Press: $. This command will record the high level sampled value to the Interrogator firmware to be used in the determination of the Sigma slope.

e. Set the variable attenuator level to 50 dB. See Figure 7-38, Log Slope

Measurement using variable attenuator.

f. Press the <CR> to initiate the low level sampling process.

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FIGURE 7-38. LOG SLOPE MEASUREMENT USING VARIABLE ATTENUATOR.

g. Displayed on the KCRT will be the channel high-level amplitude recorded from step 7(b), the current measured low-level amplitude, the previously measured attenuator value entered in step 6(c), and the calculated Log Sigma Slope. For accuracy, let the program sample long enough to attain a stable Slope value. Record the value of the slope as a reference in case an adjustment becomes necessary.

h. Press, $ when complete, to stop the test.

i. If the KCRT indicates that the “Slope alignment complete for the following channel: Sigma, the slope level has fallen into the specified range of 24.7 to 25.3 mV/dB and the accepted value will be displayed on the KCRT. For optimum results adjust the Sigma slope to a value of 25mv/dB. See figure 7-39, IF Monopulse Receiver (A5) Slope Adjustment

Locations, for adjustment location.

---OR---

If the KCRT indicates that the “Slope alignment ***FAILED*** for the following channel:

Sigma”, then the Sigma slope has fallen out the specified range of 24.7 to 25.3 mV/dB. It will be necessary to make an adjustment to the Log Sigma Slope and run the Log Slope procedure again.

For optimum performance, adjust the Sigma slope to a value of 25 mv/dB. See figure 7-39, IF

Monopulse Receiver (A5) Slope Adjustment Locations, for adjustment location.

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(1) Adjust A5A3R8 clockwise to increase the SIGMA slope.

(2) Adjust A5A3R8 counterclockwise to decrease the SIGMA slope.

NOTE: As a guideline, one revolution in adjustment approximately equals a 1 mV/dB change in the slope.

j. Make the appropriate adjustment at this time.

k. Press the <CR> to repeat slope measurement and proceed back to step 7 to rerun the procedure until the proper slope value has been attained.

---OR---

If satisfied with the SIGMA slope value Press, <CR> then proceed to step 8, the Log Auxiliary

Slope Alignment procedure.

8. Perform Log Auxiliary Slope adjustments.

NOTE: The AUX channel slope will be measured using the Sigma channel input (J2) to the

RF Receiver. There will be no need to change the location of test cable and attenuation.

a. From the KCRT, Select Channel To Align Menu, select: 2 <CR>, to select the Auxiliary channel to be adjusted.

b. Set the variable attenuation level to 0 dB. See Figure 7-38, Log Slope

Measurement using variable attenuator.

c. Press the <CR> when complete, to initiate the High Level Log Slope Sampling

Program.

d. For accuracy, let the program sample long enough to attain a stable High Level value. When a stable value has been attained Press: $. This command will record the high level sampled value to the Interrogator firmware to be used in the determination of the AUX slope.

e. Set the attenuator level to 50 dB.

f. Press the <CR> when complete to initiate the low level sampling process.

g. Displayed on the KCRT will be the channel high level amplitude recalled from step 8(d), the low level amplitude, the previously measured attenuator value entered in step

6(c), and the calculated Log Aux Slope. For accuracy, let the program sample long enough to attain a stable slope value. Record the value of the slope as a reference in case an adjustment becomes necessary.

h. Press, $ when complete, to stop the test.

i. If the KCRT indicates that the “Slope alignment is complete for the following channel: Auxiliary’’, then the slope level has fallen into the specified range of 24.7 to 25.3 mV/dB and the accepted value will be displayed on the KCRT. For optimum performance, adjust the AUX channel slope to 25mv/dB.

---OR---

j. Or if the KCRT indicates that the “Slope alignment ***FAILED*** for the following channel: Auxiliary”, then the Auxiliary slope has fallen out the specified range of

24.7 to 25.3 mV/dB. It will be necessary to make an adjustment to the Log Aux Slope and run the Log Slope procedure again. For optimum performance adjust the AUX channel slope to 25mv/dB.

(1) Adjust A5A4R34 clockwise to increase the AUX slope.

(2) Adjust A5A4R34 counterclockwise to decrease the AUX slope.

NOTE: As a guideline, one revolution in adjustment approximately equals a 1 mV/dB change in the slope.

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k. Make appropriate adjustment at this time. See figure 7-39, IF Monopulse

Receiver (A5) Slope Adjustment Locations, for adjustment location.

l. Press the <CR> to repeat slope measurement and proceed back to step 8 to rerun the procedure until the proper slope value has been attained.

---OR---

If satisfied with AUX slope value, then Press <CR> and proceed to step 9, the Log

DELTA Slope Alignment procedure.

9. Perform Log Delta Slope adjustments.

a. At the KCRT, Select Channel to Align Menu

Select: 3 <CR> to select the Delta channel to be adjusted

b. Move the RG-233 cable connected to the output of the variable attenuator to

A20HY1J1, the Delta Channel Input to the RF RCVR. Set the attenuator level to 0 dB. See

Figure 7-36, RF Receiver (A20) cables W25, W26, W27 connections and Figure 7-37, Diplexer (A19) cable W30 connection and Figure 7-38, Log Slope Measurement using variable attenuator.

c. Press the <CR> when complete to initiate the High Level Log Slope Sampling

Program.

d. For accuracy, let the program sample long enough to attain a stable High Level value. When a stable value has been attained Press: $. This command will record the high level sampled value to the Interrogator firmware to be used in the determination of the Delta slope.

e. Set the variable attenuator level to 50 dB. See Figure 7-38, Log Slope

Measurement using variable attenuator.

f. Press <CR> to initiate the sampling process.

g. Displayed on the KCRT will be the channel high-level amplitude recalled from step 9(d), the low-level amplitude, the previously measured attenuator value entered in step

6(c), and the calculated Log Delta Slope. For accuracy, let the program sample long enough to attain a stable Delta Slope value. Record this value of the slope as a reference in case an adjustment becomes necessary.

h. Press $ when complete to abort the test.

i. If the KCRT indicates that the “Slope alignment complete for the following channel: Delta,” then the slope level has fallen into the specified range of 24.7 to 25.3 mV/dB and the accepted value will be displayed on the KCRT. For optimum performance adjust the DELTA slope to a value of 25mv/dB. See figure 7-39, IF Monopulse Receiver (A5)

Slope Adjustment Locations, for adjustment location.

---OR---

Or if the KCRT indicates that the “Slope alignment ***FAILED*** for the following channel:

Delta”, the Delta slope has fallen out the specified range of 24.7 to 25.3 mV/dB. It will be

7-145 necessary to make an adjustment to the Log Delta Slope and run the Log Slope procedure again. For optimum performance adjust the DELTA slope to a value of 25mv/dB. See figure 7-39, IF

Monopulse Receiver (A5) Slope Adjustment Locations, for adjustment location.

(1) Adjust A5A3R17 clockwise to increase the DELTA slope.

(2) Adjust A5A3R17 counterclockwise to decrease the DELTA slope.

NOTE: As a guideline, one revolution in adjustment approximately equals a 1mV/db change in the slope.

j. Make appropriate adjustment at this time. See figure 7-39, IF Monopulse

Receiver (A5) Slope Adjustment Locations, for adjustment location.

k. Press the <CR> to repeat slope measurement and proceed back to step 9 to rerun the procedure until a proper Delta slope has been attained.

---OR---

If satisfied with the Delta slope Press, <CR> and proceed to step 10, the Log Omega Slope

Alignment procedure.

10. Perform Log Omega Slope adjustments.

a. From the KCRT, Select Channel To Align Menu:

Select: 4 <CR> to select the Omega channel to be adjusted.

b. Move the RG-233 cable connected to the output of the variable attenuator to

A20A1J8, the Omega Channel Input to the RF RCVR. Set the attenuator level to 0 dB. See

Figure 7-37, RF Receiver (A20) cables W25, W26, W27 connections, Figure 7-37, Diplexer

(A19) cable W30 connection and Figure 7-38, Log Slope Measurement using variable attenuator.

c. Press <CR> when complete to initiate the high level slope sampling program.

d. For accuracy, let the program sample long enough to attain a stable High

Level value. When a stable value has been attained Press $. This command will record the high level sampled value to the Interrogator firmware to be used in the determination the

OMEGA slope.

e. Set the variable attenuator level to 50 dB. See Figure 7-38, Log Slope

Measurement using variable attenuator.

f. Press <CR> to initiate the sampling process.

g. Displayed on the KCRT will be the channel high-level amplitude recalled from step 10(d), the low-level amplitude, the previously measured attenuator value entered in step 6(c), and the calculated Log Omega Slope. For accuracy, let the program sample long enough to attain a stable slope. Record this value of the slope as a reference in case an adjustment becomes necessary.

h. Press $ when complete to stop the test.

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i. If the KCRT indicates that the “Slope alignment complete for the following channel: Omega,’’ then the slope level has fallen into the specified range of 24.7 to 25.3 mV/dB and the accepted value will be displayed on the KCRT. For optimum performance set the Omega slope to a value of 25mV/dB. See figure 7-39, IF Monopulse Receiver (A5)

Slope Adjustment Locations, for adjustment location.

---OR---

If the KCRT indicates that the “Slope alignment ***FAILED*** for the following channel:

Omega”, then the Omega slope has fallen out the specified range of 24.7 to 25.3 mV/dB. It will be necessary to make an adjustment to the Log Omega Slope and run the Log Slope procedure again.

For optimum performance set the Omega slope to a value of 25mV/dB. See figure 7-39, IF

Monopulse Receiver (A5) Slope Adjustment Locations, for adjustment location.

(1) Adjust A5A4R17 clockwise to increase the OMEGA slope.

(2) Adjust A5A4R17 counterclockwise to decrease the OMEGA slope.

NOTE: As a guideline, one revolution in adjustment approximately equals a 1mV/dB change in slope.

j. Make appropriate adjustment at this time. See figure 7-38, IF Monopulse

Receiver (A5) Slope Adjustment Locations, for adjustment location.

k. Press the <CR> to repeat slope measurement and proceed back to step 10 to re-run the procedure until a proper Omega slope has been attained.

---OR---

If satisfied with the OMEGA slope value, then Press $ to enter restoration screen.

l. Slope alignments are complete. Restore the following cables:

(1) Sigma input to RF Receiver, cable W25 at connection A20HY1J2.

(2) Delta input to RF Receiver, cable W26 at connection A20HY1J1.

(3) Omega input to RF Receiver, cable W27 at connection A20A1J8.

(4) Test Target Source, cable W30 at connection A19DC1J4.

(5) See Figure 7-36, RF Receiver (A20) cables W25, W26, W27 connections and

Figure 5, Diplexer (A19) cable W30 connection.

m. When all cables are restored to the original configuration, at the KCRT

(1) Press: <CR> to return to the Log Alignment Menu.

11. Set up Log Amp Gain adjustments as follows:

a. From the KCRT at the Log Alignment Menu Screen, select: 3 <CR> to proceed to the KCRT Type Menu.

b. Enter the number that corresponds to the model number of the KCRT being used with this procedure and press <CR>.

12. Perform the Log Sigma Gain adjustment as follows:

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a. Select 9 <CR> to select All Tests. This will display and update all the Log

Amp Gain and Noise levels continuously so appropriate adjustments can be made. If option 5

(Other) was selected in step 11(b), then you will need to select number (1) corresponding to the Sigma Log amp gain because the “All Tests” screen will not update correctly with this selection.

b. Monitor the Sigma Log Gain Amplitude to ensure that it is at the specified level of 1250 +/-50mV.

NOTE: For optimum performance adjust the Sigma Log Gain Amplitude to 1250mV.

c. If Sigma Log Amp Gain “YES” is indicated, then the selected Sigma Log

Gain is at the proper amplitude and no adjustment will be necessary at this time. Proceed to step 13.

---OR---

If Sigma Log Amp Gain “NO” is indicated, then the Sigma Log Gain is out of tolerance and an adjustment will be necessary to A5A3R4.

d. While monitoring the Log Sigma Gain level on the KCRT, make the appropriate adjustment to attain a value of 1250 +/- 50 mV. See Figure 7-40, IF Monopulse

Receiver (A5) Gain And Noise Adjustment Locations. Once the proper amplitude has been attained the “NO” will return to a “YES” condition. For optimum performance adjust the

Sigma Log Gain Amplitude to 1250mV.

NOTE: If a value of 1250+/- 50 mV cannot be attained by adjustment of the Log

Sigma Gain potentiometer, then it will be necessary to adjust the Log Sigma Offset adjustment to attain the proper amplitude of 1250 +/- 50mV. When adjusting the Log

Sigma Offset potentiometer, monitor the KCRT, ensuring that the Sigma Noise level does not exceed a level of 75 mV. If the amount of Log Sigma Offset adjustment to reach a value of 1250+/- 50mV causes the Noise level to exceed 75 mV, then replacement of the IF Monopulse receiver will be necessary.

e. Once the proper amplitude has been attained. Proceed to step 13.

13. Perform the Log Delta, Omega, and Auxiliary Gain adjustment as follows:

a. Monitor the Delta, Omega, and Auxiliary Gain Amplitudes to ensure that they are within the specified range (+/-10 mV) of the Log Sigma Gain Amplitude. If option 5

(Other) was selected in step (11b), then you will need to select the number corresponding to the specific Log amp gain desired because the “All Tests” screen will not update correctly with this selection.

NOTE: For optimum performance adjust the Log Delta, Omega, and Auxiliary Gain

Amplitudes within +/-10 mV of Log Sigma Gain.

b. If the Log Amp Gain “YES” is indicated in all corresponding Log Amp

Gain fields, then the Log Amp Gains are set at the proper amplitude and no adjustment will be necessary at this time. Proceed to step 14.

---OR---

If Log Amp Gain “NO” is indicated in any of the Log Gain fields, then the corresponding Log Amp Gain is out of tolerance and an adjustment will be necessary.

c. While monitoring the specific channel’s Log Gain level on the KCRT, make the appropriate adjustment to attain a Log Gain that is within +/-10 mV of the Log Sigma Gain. Refer to the KCRT for the appropriate adjustment designation. Once the proper amplitude has been attained the “NO” will return to a “YES” condition. For optimum performance adjust the Log Delta, Omega, and Auxiliary Log Gain Amplitudes within +/-10 mV of Log Sigma Gain.

NOTE: If the necessary value cannot be attained by adjustment of the appropriate Log Gain potentiometer, then it will be necessary to adjust the corresponding Log Offset adjustment to attain the proper amplitude of 1250 +/- 50mV. When adjusting the corresponding Log Offset potentiometer, monitor the KCRT, ensuring that the corresponding Noise level does not exceed a level of 75 mV. If the amount of Log Offset adjustment used to reach the necessary value causes the corresponding Noise level to exceed 75 mV, then replacement of the IF monopulse receiver will be necessary.

d. Once the proper amplitude has been attained. Proceed to step 14.

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14. To stop the procedure completely and return to the Mode S main Menu:

a. From the KCRT, press:

(1) $ To continue back to the Select Channel to Align Menu.

(2) $ to exit and return to the Log Alignment Menu.

(3) $ to abort and return to the Mode S Calibration Menu.

(4) $ to return to the Mode S Main Menu.

NOTE: If performing this procedure in the Mode S mode of operation, then proceed to the following step (18). If performing this procedure in the ATCBI mode of operation, then proceed to step (15).

15. If this procedure is being performed in the ATCBI mode of operation, then restore the Mode S as follows:

Turn on the DPS and press the RESET button.

NOTE: In some cases in which the DPS has been turned off for an extended period of time the interrogator will stop trying to communicate with the DPS. In this case after the DPS has been turned on the interrogator channel will not return to a STANDBY condition. If this becomes the case, then you will need to turn off the STANDBY interrogator for approximately twenty seconds, then turn it back on and press the reset button on the corresponding DPS.

16. From the LMT disable automatic channel switching from the ONLINE channel as follows:

a. From the LMT main screen, use the Tog (Toggle) Chan and Tog Port to select the correct channel and port to communicate with. Ensure configuration communicating with the ONLINE channel to disable automatic switching.

b. From the Mode S main screen, select the Sensor Commands menu.

c. Open the Sensor Control menu.

d. Open the Sensor Channel menu

e. Double click on Disable Automatic, to disable automatic switching.

f. Close the Sensor Commands screen.

NOTE: Under the Auto Switching section of the Mode S main, observe DISABLED in red indicated in the Sensor Channel window.

17. From the KCRT connected to the STANDBY channel, disable automatic testing as follows:

From the Mode S Main Menu, type: 7 <CR> to disable automatic testing.

Ensure “Auto Testing Suspended” is displayed at the top of the KCRT display.

18. At the Local Maintenance Terminal, perform the following:

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a. Display the Interrogator Conditions Report (logical unit 30) for the interrogator being aligned.

b. Observe the Sigma, Delta, and Omega Video Gain values displayed in data points 2D, 2E, and 2F, respectively. Verify that the Delta and Omega Gain values are within

1.0 dB of Sigma. If they are not, then recheck the gain adjustment of each channel.

c. Using the SAP menus, select the VSP table. Set the interrogator video gain yellow and red alarm thresholds for each receiver channel to the following levels:

SAP Name Threshold Level – Video Gains lw_thr_sm_ch_vid_gn (red alarm)

Set 3 dB below the Sigma Video Gain value at LU 30 DP 2D upThr_sm_ch_vid_gn (yellow alarm)

Set 2 dB below the Sigma Video Gain value at LU 30 DP 2D lw_thr_dlta_ch_vid_gn (red alarm)

Set 3 dB below the Delta video Gain value at LU 30 DP 2E upr_thr_dlt_ch_vid_gn (yellow alarm)

Set 2 dB below the Delta Video Gain value at LU 30 DP 2E lw_thr_om_ch_vid_gn (red alarm)

Set 3 dB below the Omega Video Gain value at LU 30 DP 2F…