[Milsurplus] Navigation System

[Marty Reynolds]

This is BC-733 talk

I've been following the thread on jurrassic ILS & thot I'd
wait and see if an airfield legend on the 1st localizer
system re-emerged

      '733 built like a copper-plated brick $h!# house so
      it would survive the frequent RAF wrecks from which
      they were regularly excised.

      Marker 75mc beacons only got you so far on landing.  Loc-
      alizer would get you centered on rwy

next, this I-101 tidbit

     this isn't a legend, the BC-733 book says the 108-110 mcs
     localizer used the vertical needle on the I-101 to give a
     runway L or R indication.  It further said the horizontal
     needle is "for future use."  Hint, hint, read glide-slope
     aka ARN-5

Last the circuit

     Two yagis , two txs used on ground.  One AM modulated
     at 90 hz*, other at 110hz.  '733 had two bandpass filters
     that'd pass these freq.s.  Then two diodes and a zero-
     center ckt. to the I101's vertical movement

     WAS THIS SIMPLE AND ELEGANT OR WHAT??

     Same system/ckt.s used in 330 mcs glide-slope.

     And whole shebang still in service today!   In fact a
     B29 with properly-xtled '733 & ARN-5 could still come
     in from the twilight zone for a category-1 landing
     tonight.

     Check the 11 o'clock news


   Marty