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F-5 HUD Cathode Ray Tube

Technical Information

Catalogue No: C0418
Category: Head-Up Display [HUD]
Object Type: Module/Sub-Assembly/Component
Object Name: F-5 HUD Cathode Ray Tube
Part No: X468-J2
Serial No: D9646
Manufacturer: Rank Brimar
Division: Unknown
Platform(s): F-5
Year of Manufacture: 1987
Dimensions: Width (mm): 96
Height (mm): 96
Depth (mm): 182
Weight (g): 720
Location: Cupboard CA (CRTs) [Main Store]
Inscription(s):

Rank Brimar
Cathode Ray Tube
Made in England
CRT Type X468-J2
GEC Av Part No
9002-00016
Serial No D9646
Factory Ident No -
Code Ident K3971
Date Code 8707

Notes:

The ‘X’ in the Part No. indicated that this was a prototype design. The Matching Card is not fitted yet to this CRT to make it a Tube Unit Assenbly.

The F-5 was sold to many countries and provided a simple but effective fighter aircraft with potential for avionic upgrade. The Company worked on various upgrade programmes and in each case a replacement for the existing  Lead Computing Optical Sight (LCOS) was offered.

The earliest such replacement is seen in Catalogue No. C0022. The HUDWAC consists of three line replaceable units; the Pilot’s Display Unit (PDU), an Electronics Unit (EU) and a Weapon Data Input Panel (WDIP).

The physical configuration of the HUDWAC was designed to be drop-in compatible with all known versions of the F-5E/F. Other than removal of the Lead Computing Optical Sight (LCOS) no rearrangement of existing systems nor structural modification was necessary; the new PDU mounts onto the same LCOS tray. The HUDWAC was made to be interchangeable between F-5E’s fitted with the APQ-153 radar and AHRS and those fitted with an APQ-159 radar and an INS without any modifications. The HUDWAC monitors the armament panel switch settings and the in-built software determines the required operating mode which overall makes the system easier to use than the original LCOS.

The PDU gives a field of view nearly twice that of the ASG-29 Lead Computing Optical Sight it replaces. The unit hosts a control panel with switches and a keypad through which mission data such as target elevation and barometric pressure can be loaded. A 16mm film camera or a colour video camera can be attached to the aft end of the PDU. In this aircraft the PDU is hard mounted to a pre-aligned mounting frame, rather than an adjustable Mounting Tray i.e. it is already boresighted to the airframe. The drawback to the installation is that the PDU has to be long and narrow which is reflected in the design of the circuit boards within the unit. The High Voltage Power Supply locates on the underside of the PDU and there would be a Gun Camera and an Up-Front Control Panel fitted to customer requirements.

 

The more recent Cathode Ray Tube (CRT) for the Company Pilot’s Display Units are supplied as a CRT Assembly incorporating the CRT within its mu-metal housing. The CRT has a deflection coil within the casing which magnetically deflects the beam; focussing is electrostatic. The final anode operates at a high voltage of 18kV or more and the focus voltage is in the range 3-5kV.
A range of fine grain phosphors are used on the screen and the inside face, on which the phosphor is deposited, is accurately aligned to the mounting flange of the tube to ensure it coincides with the optical module's image plane.
When the CRT Assembly is fitted with its Matching Card it forms a Tube Unit Assembly (TUA).
The latest raster/cursive CRTs have a blank or silvered area usually at the bottom of the screen where the beam is deflected for a beam current calibration test. This is found on F-16 C/D (which introduced the idea), LANTIRN and Typhoon.

4500 Series GEC Ferranti HUD: This TUA operates in a raster or cursive mode and uses a P43 phosphor.
C-17 HUD: The circular faceplate of this CRT is blanked top and bottom to match the shallow prism optics in the relay. A P43 phosphor is used and the HUD was planned to have growth to a raster display but this was not installed. This part number in the reference database is wrongly attributed to EFA.
F-5 HUD: This is a conventional TUA and is cursive mode only with a P1 phosphor
F16A/B HUD: It was during this programme that the TUA became a subcontract item. The cursive only TUA uses a P1 phosphor
F-16C/D HUD: A large circular screen with a test area and using a P1 phosphor The TUA operates in raster/cursive and combined modes. 
Gulfstream HUD: A truncated CRT operating in cursive modes with a P43 phosphor
LANTIRN HUD: A truncated CRT operating in raster/cursive and combined modes with a P43 phosphor
Typhoon HUD: A truncated CRT operating in raster/cursive and combined modes with a high drive P53 phosphor

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