Interesting, I've got a 3 3l 40 meter KLM, 7 element F12 15 meter
monobander, and Hygain 5 el 20 meter monobander on a 20' chrome moly
mast with steps on it. And I've never had a problem.
Could the difference be that I do not pin the rotator to the mast? So
in extreme conditions the mast slips in the rototor fitting - acts like
a fuse. When the blow is over, I just loosen a couple of bolts, point
the antenna in the right direction again, and tighten up the bolts.
Happens every couple of years.
Michael
--- kk9a@arrl.net wrote:
> I would not recommend the HDR300. I owned two of
> them for several years and they needed servicing many
> times. The biggest problem was that the shaft keyway would
> elongate and become very sloppy. The antenna would then
> free spin 30 degrees. I tried making my own shafts out
> of hardened tool steel and even this didn't cure the problem.
>
> John
>
> -----Original Message-----
> From: WYsixK
> To: towertalk@contesting.com
> Sent: 4/12/2002 3:25 PM
> Subject: [Towertalk] Any glaring discrepancies?
>
> I also would suggest a different rotator. I have an HDR300 that has
> been seriously overloaded for 20 years and it has been nearly
> flawless.
>
>
> --- k6ll@despammed.com wrote:
> > > After the fourth iteration I have made the 'final' decisions.
> The
> > Spring
> > > (?) antenna/tower project will consist of 70' AN Wireless tower
> > (*massive*
> > > windloading spec!), TH7 at 5' above top of tower, Cushcraft A3WS
> > w/30m
> > > add-on at 80', and 40m rotatable dipole at 85'. All of this will
> > be
> > > (hopefully!) turned by a HAM IV rotor using a <fill-in-the-type>
> > 20' mast.
> > > (five feet of mast 'nested' in tower) I will be making one 100'
> > run of
> > > LMR-400 to an Ameritron remote coax switch at the top of the
> tower.
> > (Two
> > > 'spare' coax runs will be installed on the tower.)
> >
> > A few thoughts:
> >
> > I don't like Ham-IV's. The top and
> > bottom halves are held together by
> > self-tapping screws that are a weak
> > link. It's very
> > embarrassing to come home and find the
> > bottom half of the rotor sitting stationary on
> > the rotor plate, four screws lying in
> > the grass at the base of the tower,
> > and the antennas and top half of the rotor freewheeling in the
> wind!
> >
> > I'd swap the Ham-IV for a Tailtwister.
> >
> > I would feel better with about 1/3 of
> > the mast inside the tower.
> >
> > I'd put the TH-7 at 70' instead of
> > 75. The extra 5 feet wouldn't do anything for you, and you need
> more
> > separation from the WARC antenna.
> >
> > I'd put that little A3 at the top of the
> > mast, with the 40 dipole right below or above it, at a 90 degree
> > angle. That's your best bet for avoiding interaction on all the
> > bands.
> >
> > Let us know how you make out with the AN
> > Wireless tower. Not much customer
> > feedback on here yet.
> >
> > Dave, K6LL
> > K6LL@despammed.com
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
>
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