Spiderbeam Rotor Adapter for Alu Masts


Spiderbeam has 3 models of Rotor Adapters in its product portfolio.

It is important that you use the correct adapter for your installation.


The bottom segment of Spiderbeam Aluminum Masts come in 2 sizes: 

  • 70mm
  • 80mm


Common Rotors for Ham Radio antennas do not accept masts of these sizes.

  • Some Rotors accept masts up to 2 in. (50mm) outer-diameter
    • ​All common HyGain Rotors
  • Some Rotors accept masts up to 63mm (~2.5 in.) outer-diameter
    • ​Yaesu G-800, G-1000
  • Some Rotors "accept" masts up to 63mm, but must not be used with masts larger than 50mm! 
    • Yaesu G-450, G-650
      • WARNING:  Using this rotor with masts larger than 50mm will cause it to rotate out-of-round, which can eventually damage the bearings of the rotor.  
        • ​If the mast above the rotor is used with a thrust-bearing, limiting the horizontal movement of the mast, the bearings will be damaged.  This includes using the rotor with a Spiderbeam Tripod.
  • If no thrust bearing is used and the mast is free to move horizontally, usually no damage will occur. 
  • NOTE:  The latest instruction manuals specify the mast size as up to 50mm.  Older versions of the manual specify up to 63mm but have a WARNING (near the back of the manual) not to use masts larger than 50mm when a thrust bearing is used.





The Rotor Adapter attaches to the mast with a single, long bolt.


The user must drill his/her own 2 holes on opposite sides of the mast for attaching the Rotor Adapter.


There are currently 3 different models of Rotor Adapters and several different models of aluminum masts.


Rather than specify a distance from the bottom of the mast to the position of the holes for each combination, please measure and drill holes as shown in the drawing on the right.





Important:  be sure to drill the two holes in the bottom segment of the mast before beginning assembly.


Assemble as shown in the picture on the right.