NavList:

David Walden. It’s not a bombing computer, except for possibly to monitor IP to target.  It’s not for calculating forward throw.  I flew a few trips as en-route Navigator in a Strike Command Varsity Trainer.  Part of my job, once we got to the range, was to apply the values predicted by the T4 Bombsight in the Trainee Bomb Aimer’s Compartment to a ‘Bombing Wheel’ to check they made sense before he was allowed to release. 

You asked about the Altitude Scale.  Without a temperature input I don’t think we’re looking at altitude or airspeed corrections as on an E6B.  The device is primarily described as a radar aid, so we must look at what we might want for plotting tracks and how much a basic radar set might give us.  For plotting tracks, we want plan (or ground) ranges, but a basic radar (without a triangle solver) can only give us slant range.  Therefore, amongst the device’s many functions it must offer slant to plan range conversions.  This might explain the S and G against two of the red scales, so we are on our way to understanding how the device works and what it’s used for.  With any two of Altitude, Slant Range, and Plan Range, you can work out the third using simple trigonometry.  All we must do is fiddle about until we find how the device does it., We can assume we have Slant Range from the radar.  If we’re working Air to Ground, we’ve probably got Altitude from our aircraft instruments e.g. pressure altimeter, radar-alt, radio-alt, radar first ground return, but if we’re operating Ground to Air, we might be struggling for Altitude.  We might have it transmitted to us.  We might have a separate radar height finder, or possibly a visual angle measuring device, but if we’re really stuck, we might have to rely upon scanner tilt angle.  This might be why we have the degrees scale although it’s difficult to understand why it goes from 45 to 90.  I’ll keep looking at this although I’d have expected to be overtaken for a solution by a Professor of Applied Mathematics or an Artilleryman by now.

Note separately that as with the E6B the position of 10 on the inner black scale is highlighted.  There is also a statute to nautical miles conversion facility.  You could stick this anywhere so long as the values of the two values highlighted is in the ratio 1760 to 2025.   One other thing I observed on one of the several photographs I’ve examined is that the user has personally marked 4 minutes on the inner black scale.  They might have been doing whatever they were using it for to a four-minute cycle.  DaveP