[ARC5] ZB Discussion

[Michael Bittner]

The information on this subject that I have gathered from various references 
is as follows:  The VHF carrier transmitted by the YG Homing Beacon 
Equipment was established prior to a mission and kept constant for the 
duration of the mission.  The VHF dials on the ZB, ARR-1 and ARR-2 were set 
to this frequency and locked with the dial locks each has on its front 
panel. The ARR-2 had six channels, any of which could be preset to a 
frequency between 540 and 830 kHz.  These were preset prior to a mission. 
In the aircraft, channel changing could be done mechanically via flexible 
shaft from the pilot's control box, or electrically if the ARR-2 had 
Electric Tuning Control Adapter, C-37/ARR-2 attached to its front panel.. To 
change channels in the case of the ZB and ARR-1, the pilot would have to 
manually tune the associated BCB receiver such as ARB, etc.  The YG 
transmitting antenna, which looked kind of like a bedspring, was taller than 
it was wide, indicating a narrower beam in the vertical than in azimuth. 
Also, the antenna was tilted slightly backward so as to launch the signal at 
a slight upward angle rather than straight out to the horizon.  As such it 
would be very difficult to detect by a surface ship or surfaced submarine, 
but easy to detect by aircraft at altitude.  Direction toward or away from 
the ship, and to a limited extent distance could estimated by increasing or 
decreasing volume.  Pilots were instructed to turn the volume down as they 
got closer to the ship. The Morse code sector IDs were subject to change 
based on time of day.  Mike, W6MAB



----- Original Message ----- 
From: "Robert Eleazer" <releazer at earthlink.net>
To: <arc5 at mailman.qth.net>
Sent: Sunday, May 23, 2010 6:36 PM
Subject: [ARC5] ZB Discussion


>A friend of mine who was a USN radio technician during WWII told me that 
>both the sector codes and the transmission frequencies were changed 
>multiple times during the day and pilots had to look at a chart they were 
>provided with in order to figure out what code to use when.
>
> I would presume that the encoding frequencies (IF settings) were changed 
> too, but I would guess that happened less often.
>
> My friend also says that the pilots were told until they received the 
> signal, were told to note the altitude where reception first occurred, and 
> they given charts that enabled then to equate reception altitude with 
> distance from the carrier, presumably simply based on Line of Sight.
>
> Now I wonder if all of the ZB and ARR-2 installations were accessible by 
> the pilot of a single seat fighter?  It sure sounds like it if they had to 
> change frequencies.
>
> Thanks for the info!
>
> Wayne, WB5WSV
>