View source for AB-903

==Purpose and Use==
Purpose and Use
a. Mast AB-903/G provides the means to raise such antennas as Antenna AS-1729/VRC 30 feet above ground level. The retracted height of the mast is 72 inches. The mast may be set up on the ground, or mounted on vehicles. The mast maybe raised to full height by handcranking.


==Technical Characteristics==
:Height retracted
::6 feet. 
:Height extended
::29 feet, 3 inches. 
:Time required to raise mast (after installation of group).
::25 seconds by hand.
:Method of extending mast
::Cable-driven telescope, tubular sections, activated by crank handle.
:Tube sizes
::4 1/4-inch diameter to 1 1/2-inch diameter
:Number of tubular segments
::6
:Installation provisions
::Ground or vehicular. 
:Number of guys
::6 for ground installation. 
:Number of stakes
::3. 
:Material
::Aluminum alloy tubing, corrosion-resistant cables and hardware, aluminum alloy mounting brackets, Dacron guy ropes.
:Weight: 
::Mast
:::40 pounds. 
::Mounting brackets, guys,anchors
:::14.75 pounds. 
:Maximum wind loading
::35 mph without top guys; 50 mph with top guys.
:Load limitation
::20 lb masthead load over area of 2 square feet (Maximum allowable load on extended mast).



==Additional Files==
;{{pdf|TM_11-5985-263-15.pdf|TM 11-5985-263-15}}
:OPERATOR'S, ORGANIZATIONAL, DIRECT SUPPORT,
::GENERAL SUPPORT, AND DEPOT MAINTENANCE MANUAL
::INCLUDING REPAIR PARTS AND SPECIAL TOOL LISTS
::MAST AB-903/G (NSN 5985-00-933-2197)
::May 1970