« Previous Next »

Servo Amplifier

Technical Information

Catalogue No: C1795
Category: Navigation/Inertial
Object Type: Module/Sub-Assembly/Component
Object Name: Servo Amplifier
Part No: 6JA/6205191
Serial No: 178
Manufacturer: Marconi-Elliott Avionic Systems Ltd
Division: Inertial Navigation [IND]
Platform(s): Jaguar
Year of Manufacture: circa 1970
Dimensions: Width (mm): 120
Height (mm): 87
Depth (mm): 32
Weight (g): 189
Location: Rack RAA03 [Main Store]

E/W. F/S. Servo Amp
Ref. No. 6JA/6205191
DL 75D22750
Issue 5
Ser. No. 178


One of four Servo Amp Modules fitted to the Jaguar PMD.

This Projected Map system predates the modern digital systems and uses 35mm film as the data store. The film is stored on spools mounted in a moveable carriage. A tungsten halogen lamp provides the light source to project the map image via an optical system on to a ground glass screen. A fresnel lens covering the screen gives even illumination and intensifies the image in the pilot’s field of view. The film strip is driven between the two spools at a rate proportional to the Easterly ground speed while the carriage holding the spools is driven in a perpendicular direction proportional to the Northerly ground speed. The map can be presented as North or Track oriented. The screen can be rotated and has a track arrow. The aircraft’s present position, track and track to the next waypoint can be presented. A film can cover an area of about 750 by 750 nautical miles with a Scale change for 1:250 000 or 1: 500 000. The PMD was used in the Jaguar Navigation and Weapon Aiming Sub-System NAVWASS. The Marconi Avionics system was replaced with TIALD from 1995

Click to enlarge Click to enlarge Click to enlarge Click to enlarge