Rick,
Here is a nice video I took of the antenna about a year ago.
https://www.youtube.com/watch?v=_c-_Rq8w7Kc
Boom is 45G. Vertical Truss is 55G and side trusses are 25G. Antenna
weighs something like 1500 pounds.
I have a Green Heron controller and if you leave it in debug mode it will
show movement in the motor with the reed switch pulses for indication.
Without a pot, you don't know where it is pointed, however.
If I could easily accomplish it I would have a pot instead of the reed
switch. At least you would always know which way it was pointed.
Thanks to everyone for their responses. I will check out the options
suggested.
73...Stan, K5GO
On Fri, May 22, 2020 at 2:21 PM Richard (Rick) Karlquist <
richard@karlquist.com> wrote:
> I have a MonstIR turned by a K7NV "small" prop pitch. I don't
> know how big your Yagi is, but mine has full size elements
> (70 feet long) on a 36 foot boom.
>
> I have been having the beam turn a bit during high winds.
> It never occurred to me that the prop pitch could be free
> wheeling. I assumed it was either the mast slipping in
> the prop pitch clamp or the boom slipping on the mast.
> The K7NV has probably the best mast clamp ever made.
> Also I have a Slipp-Nott on the boom to mast plate.
> Now that I think about it, the free wheeling theory
> makes some sense.
>
> This raises the question: how did you determine that
> the slipping was due to the rotor gears, as opposed
> to the rotor to mast clamp or the mast to boom plate?
> Thinking out loud here (a bad habit of mine), should
> I leave the rotor control box turned on all the time,
> especially on windy days, with the rotor parked at zero
> degrees azimuth. AFAIK, the display on the box will
> indicate any free wheeling of the prop pitch, but will
> do nothing if the mast is slipping. So far, I usually
> turn it off when not on the air (or during a 160 meter
> contest, hi) and I am assuming it is completely off
> and wouldn't record free wheeling. The box is a legacy
> Green Heron (still works great after 15 years).
>
> 73
> Rick N6RK
>
>
> On 5/22/2020 9:29 AM, Stan Stockton wrote:
> > I have an extra large prop pitch that has been turning a large 40m Yagi
> for 13.5 years. Unfortunately the gear reduction on the extra large prop
> pitch is only 5830-1 instead of 9576-1 for the small one. I am guessing
> the small prop pitch would hold it. At any rate, although it does a fine
> job of turning the antenna, and would hold most any antenna you could
> imagine, the prop pitch has never been able to hold this antenna in
> place. I've probably replaced the coax jumper between the hardline at the
> top of the tower and the hardline on the boom a dozen times after big winds.
> >
> > I know that mounting the prop pitch outside the tower with the proper
> gears and chain I could make it hold the antenna. What I would prefer is
> to install a brake of some kind that would stop the shaft coming out of the
> bottom of the motor to keep it from turning. I would think the torque
> would be small. I haven't tried it but want to think I might hold that
> antenna in place with my fingers on the shaft coming out the bottom of the
> motor??
> >
> > Anyway, the question is this. Does anyone have an idea for an off the
> shelf product that could be adapted to stop that shaft when I wanted to
> "park" the antenna or after it is rotated with a delay?
> >
> > Thanks... Stan, K5GO
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|