You want to be very careful mounting the HD-73 without either a cage or in a
tower if you live in an area with strong or gusty winds.

In a low wind or protected area there will be no problem with mast mounting.

The issue is not the strength of the rotator housing, but the bearing races.
They are aluminum and wear pockets around the bearings where the polymer
bearings themselves ride if the mast is allowed to rock the rotator unit or they
are not kept well lubricated with a grease that does not contain clay or water.
I use Hydrotex's Parasyn, but most marine sterndrive pivot greases are suitable.
Wheel bearing grease is not.

If you need the manual, let me know. I have it on a PDF file. The manual
states that most three element CB antennas and even some vertical CB antennas
are too much load for the rotator without a bearing support above the unit.

A typical three element CB beam weighs about 16 lb., and has 3.5 square feet of
wind sail. The HD Spiderbeam weighs about 23 lb., and has 3.8 square feet of
wind sail.

Norm's Rotor Service rebuilds them to like new condition, should you need that
service.

73's

Randy

--- In spiderbeam@yahoogroups.com, "kenwooduser" <kenwooduser@...> wrote:
>
> Hi group,
>
> I've been given information that the HD-73 is derated from 10sq ft wind load
down to 5sq ft wind load when it is mast mounted, that one should only extend
the standpipe no more than 1ft above the rotator, and that the standpipe should
be 1 7/8 - 2" OD.
>
> I was planning to use the HD-73 atop a crank-up mast to turn a spiderbeam.
The biggest problem I see is the height of the standpipe above the rotator. You
have to have enough standpipe for guying the spiderbeam spreaders, mounting the
balun, etc.
>
> Are any of you out there using an HD-73 with a spiderbeam? Can you detail
your configuration?
>