SOW - ARSR4 Oscillator X2 CCA.pdf

NAS Defense Programs

Statement of Work for ARSR-4 Oscillator X2 Circuit Card Replacement

By: Gregory Stewart, Senior Electronics Engineer, AJW-1421

Date: 19 August 2024

WARNING: This record contains Sensitive Security Information that is controlled under 49 CFR parts 15 and 1520. No part of this record may be disclosed to persons without a “need to know”, as defined in 49 CFR parts 15 and 1520, except with the written permission of the Administrator of the Transportation Security Administration or the Secretary of

Transportation. Unauthorized release may result in civil penalty or other action. For U.S. government agencies, public disclosure is governed by 5 U.S.C. 552 and 49 CFR parts 15 and 1520.

NAS Defense

Programs

Federal Aviation

Administration

19 August 2024 Statement of Work

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1 Introduction The Air Route Surveillance Radar model 4 (ARSR-4) is a Long-Range Radar (LRR) that operates in the L-Band frequency range (1240 MHz to 1390 MHz). The system was developed in the late 1980s and early 1990s by

Westinghouse Electric (now Northrop Grumman). As the system has aged, obsolescence of components has become an issue for the continued supportability and operation of these systems. Due to obsolescence, the

Federal Aviation Administration (FAA) is seeking a redesign of the Oscillator X2 Circuit Card Assembly, hereinafter referred to as the X2CCA.

1.1 Current Design

The information contained in this section is for reference and does not necessarily reflect the requirements of a replacement X2CCA board.

The X2CCA is used within the Oscillator Assembly of the ARSR-4 to provide a base frequency that is eventually multiplied to produce the Stable Local Oscillator (STALO) frequency for the radar. The Oscillator Assembly contains nine separate X2CCAs with frequencies in the range from 45.5929 to 48.4250 MHz. The output of the

X2CCAs is twice this frequency range, or 91.1858 to 96.8500 MHz. Within the range of frequencies, there are

20 different frequencies available for selection. Within the Oscillator Assembly, there are nine X2CCAs, eight of which will have different frequencies selected from the 20 that are available, and one has the same frequency as one of the other eight X2CCAs.

Each X2CCA contains a BT-cut crystal oscillator and frequency doubler. A BT-cut crystal is a piezoelectric plate cut from a quartz crystal at an angle of rotation (about the X-axis) of -49 degrees. The X2CCA has exceptionally low noise. A heater that keeps the crystal at 149 degrees Fahrenheit maintains long-term stability. At each

X2CCA output, a frequency doubler multiplies the oscillator frequency by two. When a specific X2CCA is selected, its output becomes the output of the Oscillator Assembly and the other X2CCAs in the assembly are disconnected.

Both the input and the output of the frequency doubler are switched ON or OFF, depending on whether the

X2CCA is selected for the STALO. The frequency select A1 of the Oscillator Assembly controls the switches via signals OSC1CMDF through OSC9CMDF. A transistor-transistor logic (TTL) high level turns the output of the

X2CCA ON and a low level turns the output OFF. The output of the frequency doubler is connected to the 9:1 switch (A20) within the Oscillator Assembly.

The output of the oscillator on the X2CCA is detected to supply a built-in test (BIT) signal. An oscillator fault causes a loss of its output and, in turn, a loss of detected voltage. The result is a low condition on signals

OSC1FDET through OSC9FDET. Signals OSC1FDET through OSC9FDET are connected to the oscillator fault detector on frequency select A1 of the Oscillator Assembly.

The inputs, outputs, and test points for the X2CCA are provided in Table 1.

Table 1 – X2CCA Inputs, Outputs, and Test Points

Reference Designator Signal Name Type Description

J1 OSCTEST Test Point A sample of the RF voltage developed at the collector of transistor Q1 is available, at a level of greater than +3 dBm; normally-terminated SMA test connector J1

E1 +11.6VF* Input +11.6 VDC; non-insulated double turret terminal for soldering wire to board

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Reference Designator Signal Name Type Description

E2 -11.6VF* Input -11.6 VDC; non-insulated double turret terminal for soldering wire to board

E3 GROUND Output Ground; non-insulated double turret terminal for soldering wire to board

E4 +15VRTN Output +15V return; non-insulated double turret terminal for soldering wire to board

E5 +15VF* Input +15 VDC; non-insulated double turret terminal for soldering wire to board

E6 OSC*FDET Output BIT signal that is +1.4 to +2.4 VDC when circuit functioning properly; non-insulated double turret terminal for soldering wire to board

E7 OSC*OUT Output Output of frequency doubler; non-insulated double turret terminal for soldering wire to board

E8 GROUND Output Ground; non-insulated double turret terminal for soldering wire to board

E9 OSC*CMDF Input TTL level signal that turns the oscillator X2 output on or off; non-insulated double turret terminal for soldering wire to board

E10 CVADJ Test Point

Reference voltage (+4.5 VDC) set by variable resistor R40 to control the gain of the oscillator from operational amplifier U1; non-insulated double turret terminal for soldering wire to board

E11 OSCTP Test Point Output voltage from operational amplifier U1; non-insulated double turret terminal for soldering wire to board

For more details on the current design and operation of the X2CCA and the Oscillator Assembly, refer to

Technical Instruction (TI) 6340.26 Chapter 8, Volume 8. Within the TI, there are technical descriptions, detailed descriptions, block diagrams, and schematics for the Oscillator Assembly and subcomponents, to include the

X2CCA. Images of the current design are provided in Figure 1 through Figure 3.

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Figure 1 – X2CCA Top View

Figure 2 – X2CCA Bottom View

Figure 3 – X2CCA Side View

1.2 Current Bench Test & Evaluation

The X2CCA is evaluated on the Low Level Radio Frequency (LLRF) test set for performance, tuning, and troubleshooting errors. The repair data, test details, and associated drawings are located within TI 6340.57 paragraph 19. The test fixture is shown in Figure 4 through Figure 6.

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Figure 4 – Test Fixture, Top View

Figure 5 – Test Fixture Front View

Figure 6 – Test Fixture Side View

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2 Scope of Work This Statement of Work (SOW) describes the tasks the Contractor must perform for the design, verification, test, and delivery of the redesign for the ARSR-4 Oscillator X2 Circuit Card Assembly (X2CCA) according to the design requirements, form, and intent contained herein.

2.1 Definitions

All reference to the “Government” in this SOW shall mean by authority of the Contracting Officer (CO) or their designee(s). Reference to Government approval shall be limited to the CO and their Representative(s). The term software, as used in this SOW, refers to any code developed or otherwise used, including code for firmware and all support files (e.g., library files, project files, test development software, etc.) needed for editing/making changes for future modifications.

For the purposes of this SOW, any item manufactured or modified by the Contractor, or their subcontractor(s), is defined to be non-COTS if there are no commercial customers other than the United States Government.

2.2 Tasks to be Performed

1. Evaluate existing X2CCA design and automated tests.

2. Design replacement X2CCA, adhering to the requirements set forth in section 4 of this SOW.

3. Assemble a First Article X2CCA for test and evaluation. X2CCAs shall be tested according to requirements set forth in section 5 of this SOW.

4. Upon acceptance of the First Article, assemble the types and quantities of the new X2CCA design, as set forth in section 0 of this SOW.

5. Deliver the assembled and verified X2CCAs to the FAA.

6. Deliver the intellectual property of the new design to the FAA, to include but not limited to:

a. Native design data files, e.g., schematics, layouts, drawings, fabrications, fixtures, datasheets, test reports, etc. Note: native design data files are preferred to be in Siemens/Mentor

Graphics format for DxDesigner and Expedition software applications. If design done in a different software application, identify the software application used and additionally provide exported translation files for import into DxDesigner and Expedition software applications.

b. Portable format of native design data files, i.e., PDFs of schematics, layouts, drawings, fabrications, fixtures, datasheets, test reports, etc.

c. Updated bill of materials for the design(s).

d. Any other files and/or documentation necessary to allow for the US Government to manage, maintain, and potentially modify the design for future needs.

7. Deliver all test fixtures, software, documentation, etc. related to evaluating, configuring, adjusting, etc.

the X2CCAs.

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2.3 Quantities

The Table 2 lists the quantities requested for the 20 different versions of the X2CCA for a total procurement of

96 boards. The First Article X2CCA crystal frequency shall be 46.402 MHz

Table 2 – X2CCA Quantities

Part Number Crystal Freq.

(MHz)

X2CCA

Output Freq.

(MHz) Qty to

Purchase

3D57426 45.593 91.186 0

3D57427 45.674 91.348 0

3D57428 45.755 91.510 2

3D57429 45.836 91.672 1

3D57430 46.240 92.480 15

3D57431 46.321 92.642 0

3D57432 46.402 92.804 22

3D57433 46.483 92.966 8

3D57434 46.888 93.776 11

3D57435 46.968 93.936 0

3D57436 47.049 94.098 16

3D57437 47.130 94.260 2

3D57438 47.535 95.070 7

3D57439 47.616 95.232 1

3D57440 47.697 95.394 4

3D57441 47.778 95.556 0

3D57442 48.182 96.364 7

3D57443 48.263 96.526 0

3D57444 48.344 96.688 0

3D57445 48.425 96.850 0

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3 References The following specifications, handbooks, orders, standards, and drawings form a part of this SOW.

3.1 FAA Standards

FAA-G-2100 rev H Electronic Equipment, General Requirements

3.2 Design and Reference Documentation

1A20886D Crystal Oven

1A20917H Switch

1A20956H Crystal

1A20959E Frequency Doubler

1A21003 Diode, Varactor, 30VDC, 95_105pF @ 1MHz & 4 VDC

1A28667 Test Spec, X2 CCA w/ crystal

3A22840 Test Spec, X2 CCA w/o crystal

3D57026 Oscillator X2 Schematic Diagram

3D57027 Oscillator X2 Circuit Card Assembly wo Crystal

3D57028 Oscillator X2 Printed Wiring Board

3D57426 Oscillator X2 Circuit Card Assembly with 45_593 MHz crystal

3D57427 Oscillator X2 Circuit Card Assembly with 45_674 MHz crystal

3D57428 Oscillator X2 Circuit Card Assembly with 45_755 MHz crystal

3D57429 Oscillator X2 Circuit Card Assembly with 45_836 MHz crystal

3D57430 Oscillator X2 Circuit Card Assembly with 46_240 MHz crystal

3D57431 Oscillator X2 Circuit Card Assembly with 46_321 MHz crystal

3D57432 Oscillator X2 Circuit Card Assembly with 46_402 MHz crystal

3D57433 Oscillator X2 Circuit Card Assembly with 46_483 MHz crystal

3D57434 Oscillator X2 Circuit Card Assembly with 46_888 MHz crystal

3D57435 Oscillator X2 Circuit Card Assembly with 46_968 MHz crystal

3D57436 Oscillator X2 Circuit Card Assembly with 47_049 MHz crystal

3D57437 Oscillator X2 Circuit Card Assembly with 47_130 MHz crystal

3D57438 Oscillator X2 Circuit Card Assembly with 47_535 MHz crystal

3D57439 Oscillator X2 Circuit Card Assembly with 47_616 MHz crystal

3D57440 Oscillator X2 Circuit Card Assembly with 47_697 MHz crystal

3D57441 Oscillator X2 Circuit Card Assembly with 47_778 MHz crystal

3D57442 Oscillator X2 Circuit Card Assembly with 48_182 MHz crystal

3D57443 Oscillator X2 Circuit Card Assembly with 48_263 MHz crystal

3D57444 Oscillator X2 Circuit Card Assembly with 48_344 MHz crystal

3D57445 Oscillator X2 Circuit Card Assembly with 48_425 MHz crystal

583R161 Amplifier, RF, 11.1VDC, 0.115A, 12dB, 20_30MHz

645A736 Resistor, Fixed

PS80282SA Printed Wiring Board, Requirements For

TI 6340.26 Chp 8, Vol 8 ARSR-4 System Oscillator Module LRU Manual

TI 6340.57 Chp 19 ARSR-4 System UUTs Tested on LLRF Test Set – Oscillator X2 CCA Test

TI 6340.57 Chp 20 ARSR-4 System UUTs Tested on LLRF Test Set – Oscillator Assembly Test

Commented [SG(1]: Are there any other design documents or standards we should reference in this section?

Commented [WL(2R1]: I think that's about all we have.

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4 Design Requirements The design must be a form-fit-function (FFF) replacement that will fit and function within the existing Oscillator

Assembly in such a manner that once installed inside the assembly it is indistinguishable from the original. It must perform as well or better than the existing design in terms of stability, noise, and accuracy but how this is implemented is left to the discretion of the Contractor.

• Board dimensions — the replacement design must fit in the exact same physical space as the original

• Terminal and interface positions / functions — the replacement design must have inputs and outputs in the same locations as the original and the function of the input/output must also remain the same, refer to Table 1

• Mounting holes — since the board must mount within the same assembly as the old board, it must have the same mounting hole location and sizes

• Component position — the location of the components on the board is irrelevant, as long as the external interfaces are in the same location as the original. However, only the top side of the board may be utilized for component placement due to installation within the Oscillator assembly

• Component height — clearance is not anticipated to be an issue for concern but component heights larger than the current design should be validated to fit within the Oscillator Assembly

• Test points — any existing test points must be duplicated on the new design in the same locations so as to be compatible with the existing test fixture, this includes an exposed ground plane pad on the bottom side of the board, which is shown in figure X

The frequency output from the board must be as stable or more so than the original design, with no more noise than the original design.

4.1 Performance Characteristics

For details on performance characteristics, refer to test specification 1A28776.

• Signal ON/OFF Ratio > 120 dB

• RF Power Out > +2 dBm

• BIT Voltage V > 1.3 VDC

• Nominal Freq See Figure 3 of Test Spec 1A28776

• Nominal Freq (F1) – Measured Freq (F2) -1000 Hz < (F1 – F2) < +1000 Hz

• J1 Output Power > +3 dBm

• Phase Slope See Figure 4 of Test Spec 1A28776

Commented [SG(3]: Still need to write. Thinking it will be fairly top level. Key is, make as few changes as possible, but expect changes to occur. What are the key points that cannot change???

•Board dimensioning

•Terminal positions

•Exposed ground plane on underside, with screws for various components able to be "shorted" to that ground plane

•Components only on top of board

•Max height of components on board

Any other "must have" requirements?

Commented [WL(4]: I thought about test points, but if we're only doing the testing in the next level up assembly then that might not be necessary.

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5 Test and Evaluation Requirements

5.1 Bench Test

For each unit manufactured, a test data report of the performance characteristics of the unit shall be generated. The following performance characteristics, at a minimum, shall be included within the test data report.

• Signal ON/OFF ratio

• RF Power Output

• BIT Voltage Output

• Measured Frequency vs Nominal Frequency

• J1 Output Power

• Phase Slope / Noise Response Curve

• Measured Voltage Adjustment Parameters, as applicable to the design (e.g., AGC voltage, ALC voltage, etc.)

5.2 First Article Testing

Upon successfully passing the bench test, the First Article shall be provided to the FAA for evaluation.

5.2.1 X2CCA Test Fixture Evaluation

If the design of new X2CCA is done in a manner that allows for evaluation of the board in the existing test fixture apparatus, as described and illustrated in Section 1.2, then the First Article shall be evaluated as defined in TI 6340.57 Chapter 19 Oscillator X2 CCA PN 3D57426G01 Through PN 3D57445G01 Repair. The First Article must pass all test and evaluation items identified in Chapter 19.

5.2.2 Oscillator Assembly Bench Test Evaluation

The First Article shall be installed within a functional Oscillator Assembly and evaluated as defined in TI

6340.57 Chapter 20 Oscillator Module PN 3D59638G01 Through PN 3D59645G01 Repair to ensure correct operation of the Oscillator Assembly. The Oscillator Assembly must pass all test and evaluation items identified in Chapter 20.

5.2.3 ARSR-4 In-System Evaluation

The Oscillator Assembly with the First Article installed shall be inserted into the ARSR-4 at the Mike Monroney

Aeronautical Center (MMAC) in Oklahoma City, OK.

1. Ensure there are no alarms related to the Oscillator Assembly for the Built-In-Testing (BIT).

2. Run the Fault Isolation Testing (FIT) for the Frequency Generator (menu 4.4).

3. Ensure ARSR-4 Oscillator configuration can be altered from the First Article X2CCA and then back again, maintaining operations (BIT alarms).

4. Perform the following periodic maintenance checks. Results should be close to those measured using the non-modified Oscillator Assembly.

a. Transmitter Peak Power, MTHB 6340.26A Paragraph 4-10(b)

b. Receiver MDS, MTHB 6340.26A Paragraph 4-10(c)

c. Transmitter Pulse Width, MTHB 6340.26A Paragraph 4-11(a)

d. Transmitter VSWR, MTHB 6340.26A Paragraph 4-11(b)

e. Transmitter Spectrum, MTHB 6340.26A Paragraph 4-12(c)

f. ARSR-4 System Reconfigurable Elements, MTHB 6340.26A Paragraph 4-20(a)

Commented [SG(5]: How are we going to test and evaluate the first article? Follow-on boards?

Commented [WL(6]: Want to add "for a period of x days"?