[Milsurplus] "Sideband Modulator?"

[Cletus W Whitaker]

de WB2CPN  South Central Pennsylvania   2004.07.22

How big is it?  The CAA Instrument Landing Systems (ILS)
and their Visual-Aurial Ranges (VAR) used a system of
carrier and independent sidebands to produce the courses
the aircraft followed.  The military had their SCS-51
ILS system which used a mechanical modulator on the
localizer and glide slope, as did the USAF AN/MRN-7
and AN/MRN-8.  The CAA set-up for both their ILS and their
VAR used three main components:  An AM VHF transmitter
for ID and Voice at very low modulation levels, and a
motor-generator that produced 90 and 150 Hz power for
the sideband generator unit.  These are rack sized.
They had table-top versions for shop alignment of the
aircraft equipment.  I helped install and maintain a
CAA ILS and VAR in Germany during the "Airlift" of
1948/1949.  Yes, Virginia, it happened.  We had a VAR
at Volkenrode, and an ILS at Wolfenbuttle.  They're
near Braunschweig in what was the British Zone.

73  Clete   a.k.a. Trivia For The Day