[TowerTalk] Ring Rotors

[Steve Maki]

On 1/30/2023 1:48 PM, Lux, Jim wrote:

> On 1/30/23 9:46 AM, Grant Saviers wrote:
>> I agree side mount + swing arm is a good option.
>>
>> Although my 7 K0XG R65 rings have worked great minus one motor 
>> failure, I would do side mounts for future (unlikely) towers.
>>
>> The advantages of side mounts are lower cost & weight, using standard 
>> rotators, and if desired with multiple beams on a long mast between 
>> rotator and top support.
>>
>> The side mount disadvantages are less rotation (but still can get 
>> ~250*), some offset load on the tower (use 6 guys or star brackets), 
>> and easily fabricated or purchased unique parts, although you/PE need 
>> a design.
>>
>> I think the updated Orion 2800 is a better choice than the Yaesu for 
>> very big beams. 

> I've been thinking about this, and I wonder if there were some "not too 
> complex" scheme with an extra hinge point on the arm that would get you 
> 360 degrees.  Not that I would build such a thing (would that I had room 
> for it) - but I was thinking if you had an arm that is the length of a 
> "face" of the tower, and some sort of offset crank linkage, you could 
> get 360 of rotation from 240 degrees (or less) of movement from the 
> primary arm.   My mind's eye has this as like a "wrist" that reaches 
> around the tower. Yeah, you'd have the mass of the antenna as a 
> cantilever load, which would put a bending moment on the tower.

A swing arm where the rotor is mounted straight off a tower leg is good 
for 300° easy. That's plenty as long as you have another antenna to 
cover the dead zone.

-Steve K8LX