[Milsurplus] Jurrassic air-nav / was TCS in PT

[C Whitaker]

de WB2CPN   'Ol AACS man since '46.

I know I'm going to regret this, but here are
some things to know:

Localizers and GlidePaths use 90 and 150 Hz.
So did VAR's when they existed.  Those freqs
are the third and fifth harmonics of 30 Hz.

The military SCS-51 was the first ILS, and was
developed by the CAA who designed fixed plant
equipment for their own needs.

The BC-400 was a two-transmitter "Z" marker,
wasn't it?

USAF used three marker beacons up until about
1950.  It wasn't because it was a localizer only
approach.  When it came out, the MRN-8 Glide Path
had a "course modifier" antenna that made the
useable vertical guidance go right down into the
runway.

The Brits and the Germans had similiar ILS systems,
but they weren't exactally the same.

Been there, had fun.

73  Clete