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This document describes updates needed to address a potential issue with the RI8587 receiver. The RI8587 receiver TIM's IF input ports 'IF In A' (C10), 'IF In B' (C11) or 'IF In C' (C12) may have reduced accuracy when the receiver instrument's If Bw is set to 7 kHz. This fix removes that inaccuracy by incorporating an additional calibration (cal) factor in the receiver.

Note: The following TIMs use the receiver's IF input ports. Testers equipped with the following TIMs may experience this issue:
- RI8563, 4-40.5 GHz Test Set
- RI8580 56-67 GHz Test Set
- RI8564 71-86 GHz Test Set

TIM Serial Numbers affected by this issue: RREWGW0A, RSHUNC0A, (and any other RI8587A4 TIMs built after April-2016) RRZVRN0A

Measurements with the Receiver instrument BW Filter set to 7 kHz and input set to any of the available IF input ports may be less accurate. The updated calibration and verify test plans will fail to compile when the patch or RiInstrumentDef is missing. Even if the calibration data exists (i.e, from the factory), the patch must be loaded for it to be effective.

Update Instructions
1) Import the "RBEH-A9Q2UB_Service_Bulletin.gzp" file via Guru Browser.
2) Update or create a new ShortCut to include this patch.
3) Calibrate the RF System with the newly created or updated ShortCut using a standard calibration procedure.
4) Run all User Apps, Test Execs with the newly created or updated ShortCut that includes this patch.

Note: the GZP also includes all support files included with the RiInstrumentDef manifest and Cert objects (23 total objects)

Four(4) Guru objects are required to fix this issue:
1) RiInstrumentDef (ri.sys.ObjClass="RiInstrumentDef", ri.sys.Title="RI8587A .01 to 20 GHz Complex Receiver TIM w DSP", Creation Date of 2016-04-26 or later).
2) Patch 200.22 (ri.sys.ObjClass="RiPatch", ri.sys.Title="Improvements to DSP Receivers", Creation Date of 2016-04-28 or later).
3) Calibration test plan (ri.sys.ObjClass="RiTestplan", ri.sys.Title="RI8587A IF Gain Cal w Testhead", Creation Date of 2016-05-12 or later).
4) Verify test plan (ri.sys.ObjClass="RiTestplan", ri.sys.Title="RI8587A Verify Detectors w Testhead", Creation Date of 2016-05-12 or later).

- The InstrumentDef is required to define the calibration factor and set its default value.

- The patch is required for the Cassini software to know how to apply the calibration factor. It must be included in the Short Cut (provided by RI or customer-modified using the Guru Update Manager) or manually loaded.
To manually load:

- From the main Cassini window, select Program > Guru Patch...
- Select Load. find the patch "update 04-28T12:29 GF10RC2A.200 Improvements to DSP Receivers" then press the Load button.

- The calibration and verify test plans are needed to set the correct value. As they are updates to existing test plans, they are already in your Cal List (accessed from the configuration window Tester > Calibrate menu) and are automatically loaded by the normal Calibration procedure. The Cal List does NOT need to be updated because the Title of the calibration and verify test plans did not change.

To Verify Installation
  • Open Guru Browser, confirm the modified objects are in Guru, with the appropriate dates.
  • Calibration values should exist in the Receiver Instrument's calibration data.

  • Detailed Explanation

    A1 hardware revision included the same path for internally and externally routed IF signals. When the 7 kHz filter is switched in/out, all the IF's went through the same path.

    A2-4 hardware revisions added an extra filter on the mixer board to improve the out-of-band rejection of the 7 kHz filter. When in the 7 kHz mode, both filters switch in, generating more out-of-band rejection. When using 7 kHz BW, the RF and low frequency go through 2 filters where the IF from the 'IF In A' (C10), 'IF In B' (C11) or 'IF In C' (C12) ports only go through one filter. The loss correction for the additional filter was applied but the filter is not in the path. This update creates and calibrates a separate 7 kHz BW cal factor for external IF inputs.

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