art unwin wrote:
> Hello Marc,
>
> Prop pitch ruined ???? Not so !
> There is a brake that originally came with the prop pitch
> that many hams did not connect up. Mine handles the wind
> with a 35 foot boom plus 13 elements with the brake supplied.
> It did move a 80 foot boom into the wind which really didn,t
> bother me otherwise I would have increased the brake power
> ( There is an advantage to having the antenna turn into the wind
> rather than it be battered to death )
> Usually those that complain of wind rotation have not
> connected the supplied brake or given thought to adding one
> Of course a small beam (< 20 foot),does not require a brake.
You are right on this point, Art. I never did try to hook up the
brake or make any other effort to brake the rotator. Of course, the
original brake may be missing and lost forever at this point in time .
. .
> If you use a variac ( or a speed control unit) you can
> vary the voltage for any speed desired.( Together with
> a controled start and stop if you really want to get fancy).
I use a Variac without controlled start or stop.
> I do not recomend the use of selsyns, they are a cause of
> problems in inclement weather. I made a circular 1 inch
> wide band of aluminum with the points of the compass
> marked on it and secured it to the mast.
> I use a cheap miniature c.c.d. camera ($40 new )aimed permanently
> at the band and can see the direction it is pointed at
> on a c.c.d monitor or t.v.in the shack.( 40 odd years have
> passed since that article was printed )
I have had a set of selsyns in place since 1975 using bycycle chain
drive with no problems, so far . . .
> If the rotor has been modified with securing screws
> as shown in the original C.Q. magazine article I
> would recommend that you weld 3 -1 inch dia by 1 inch long
> to the underside of the bell housing instead so they mesh
> with the 3 tapered, weight saving, holes in the circular sun gear.
> These are much stronger than the questionable securing method
> (shear resistance)originally described and is more inline
> with the rotors original design torque abilities.
>
> If the rotor is to be used only for turning an antenna then
> there is no need for the oil as there is no danger of overheating
> and the non weld additive in the oil does not come into play
> As with all rotors use a mast bearing to support your antenna
> leaving the rotor to deal only with rotation especially with
> a prop pitch where the vertical load bearing system is not
> the greatest
> Good luck
> Art Unwin
I use a thrust bearing and no oil in the gear box with mine.
Stan
w7ni@teleport.com
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