[ARC5] ARR-1

[Leslie Smith]

  Jim,

  In Wikipedia, under ARC-5 this appears:
 "The broadcast band receiver in all of these command sets is intended
 to host a homing adapter for the Navy ZB/YE homing system. The homing
 adapter demodulates a signal near 246 MHz that is modulated with a
 broadcast band carrier. The output is sent to the broadcast band
 receiver tuned to the modulating frequency to further demodulate the
 carrier for voice messages or for a Morse code letter indicating to the
 pilot his bearing from the homing transmitter. All broadcast band
 receivers came with a power adapter to supply power to the homing
 adapter. The adapter under the Navy nomenclature system is the
 ZB-series. The identical unit under JAN nomenclature is the AN/ARR-1.
 This system was used by both the Navy extensively and the Army much
 less so. To put the system into operation on the aircraft, the beacon
 band receiver would be replaced in the rack by the broadcast band
 receiver. The antenna post is connected to the output of the homing
 adapter, and a power cable is connected from the homing adapter to the
 broadcast band receiver. The normal control that had been used for the
 beacon band receiver also serves this homing system without further
 reconfiguration."

  It seems to me that the ZB apparatus was used to guide pilots to
  "base" - sometimes an aircraft carrier.
  Therefore - it was essential (if I'm correct, as I believe I am) that
  this gear (or even a knowledge of it's existence) never fell into Jap
  hands.
  The disguise here seems to be several layers deep.  For a start the
  frequencies on the "ZB' converter were displayed missing the zero, so
  when the dial read "42" it was tuned to 420 MHz etc.
  Next, who would imagine modulating a 420MHz signal with a 1MHz
  carrier?  So (if the Japs had a receiver that would receive VHF (I
  doubt this) and the "tuned" the "ZB" signal - they would hear nothing. 
  You need to convert the VHF signal to the BC band, and then demodulate
  that signal.
  Finally, the deception depended on the similarity between the BC band
  receiver (CBY-46145) and the lower frequency nav band receiver
  (CBY-46129) 
  If the BC band receiver appeared superficially similar to the normal
  nav. band receiver, it would not attract much attention to a casual
  observer.

  It may be I'm wrong in my surmising, and if so, I'm sure a correction
  will be posted.  


  73 de Les Smith
  vk2bcu at operamail.com


On Tue, Sep 16, 2014, at 12:02, J Mcvey via ARC5 wrote:
> I looked up a schematic to see what that ARR-1 was. It looks to be some
> kind of TRF receiver that the output is fed back into another receiver
> via a interface box. Seems like a rather convoluted setup!  Why didn't
> they make it another stand-alone rack mount receiver like the others?
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

-- 
http://www.fastmail.fm - Access your email from home and the web