[Milsurplus] Spares boxes - ZB

[Mike Morrow]

Marty wrote of the ZB:

>The Pilot on each had to know CW & be equipped with the locator table
>b4 takeoff.  Dead simple system that was top secret thru 60s - USN
>planes cud find carriers in bad wx, other side cudn't

The ZB, ARR-1, and ARR-2  maintenance and operation manuals in WWII were
classified at the lowest level of "Restricted" and were completely
declassified after the war.  However, I suspect that the signal direction
decode card was of a much higher classification while effective, just like a
crypto code or setting card would be.

>System was never used on by Collins since he & his SBD became island-based.


I wonder if they ever used a ZA ILS as discussed in my last posting.   That
was land-based.

It seems to me that a ZB homing system would still be useful for finding
island strips.  In fact, if the USAAF ever actually used the BC-946-B and
R-1/ARR-1 equivalent, I suspect that it would have been to help their
aircraft find their island bases in the Pacific.

>'way fewer people now could explain ZB-YG operation than there
>were in 1949.


Yes, it is sort of clever...a 246 mc TRF receiver whose detector stage
outputs a keyed or AF-modulated broadcast band carrier instead of an audio
signal.  Said signal then fed to a BC band receiver to reproduce the Morse
or voice signal in the pilot's headset.  At least the aircraft carrying the
ZB, ARR-1, or ARR-2 gear weren't carrying a receiver that used a VHF local
oscillator in the front end.

I have to believe that it didn't take the Japanese long to come across the
hardware and figure it out.  Still, without the decode card all the enemy
might be able to do is home in on the carrier's VHF signal with an
appropriately designed receiver, which apparently they never bothered to do.

Mike / KK5F