RotorEZ from Idiom Press will calculate the offset automatically
by closing a switch. It might be possible to read the direction
for both antennas from the bottom rotor and control both the
top rotor and the offset with a simple toggle switch (0/90).
73,
... Joe Subich, W4TV
microHAM America, LLC.
www.microHAM-USA.com
PS. Don, the second resonance on the D-40 is closer to 17 meters
than 15 (AO says 75 + j50 at 18.1 vs. 200 + J250 at 21.1).
> -----Original Message-----
> From: rtty-bounces@contesting.com
> [mailto:rtty-bounces@contesting.com] On Behalf Of Dave W7DPW
> Sent: Thursday, November 24, 2005 2:50 AM
> To: Doug Faunt N6TQS +1-510-655-8604; t3@semarg.ath.cx
> Cc: rtty@contesting.com
> Subject: Re: [RTTY] Novel idea?
>
>
> RT-20 rotor will do just that. (Spendy)
>
> http://www.greenheronengineering.com/
>
> It was hiugh lited in current NCJ
>
> Dave W7DPW
>
> ----- Original Message -----
> From: "Doug Faunt N6TQS +1-510-655-8604" <faunt@panix.com>
> To: <t3@semarg.ath.cx>
> Cc: <rtty@contesting.com>
> Sent: Wednesday, November 23, 2005 11:43 PM
> Subject: Re: [RTTY] Novel idea?
>
>
> > Date: Wed, 23 Nov 2005 20:09:33 -0500
> > From: t3 <t3@semarg.ath.cx>
> >
> > I can't see a problem..
> > except, maby the rotor cable on the upper rotor may get
> large doses
> of
> > RF while it passes between the A3S
> > a simple fix could be sheilded cable..
> >
> > Tony
> > NN1D
> >
> > Another fix for this would be to run the control cable fro
> the rotator
> > up through the mast, come out the top and then down to the rotator.
> >
> > I like the idea, and it cries out for a couple of computer
> controlled
> > rotators and a microprocessor to be the glue to actually
> calculate and
> > display the radiating directions for the top antenna. I'm not
> > volunteering, though.
> >
> > 73, doug
> >
> >
> > Don Hill AA5AU wrote:
> > > This is not directly related to RTTY, but again, I trust the
> opinions of those
> > > on this reflector. A great bunch of ops here.
> > >
> > > I've not ever heard of anyone doing this before. But
> it seems to
> be an
> > > excellent solution for me. I was going to keep this
> secret, but
> I just can't.
> > > I need some input from others.
> > >
> > > I'm in the middle of rebuilding my main tower. Right now, it's
> at 46 feet
> > > waiting for me to install the first set of guys. Why
> the unusual
> height? Six
> > > feet of tower sticks out from the concrete base. What I have
> left is one more
> > > 10' midsection, then the 9' top section. The tower will be at
> 65' when
> > > finished.
> > >
> > > Anyway, for those following my rebuild may remember
> that I wanted
> to install a
> > > 40 meter beam. Well, I cheaped out on this idea. In order to
> get something up
> > > for Roundup, I've purchased a new A3S and D40 (D40 is
> a Cushcraft
> 40M dipole).
> > > You have to realize that my ground crew consists of my wife and
> the neighbor's
> > > German Shepard. So I have to stay lightweight right now.
> > >
> > > Prior to Katrina, my main antenna was an A3S with the 40 meter
> add-on. With the
> > > D40, the rotatable dipole will now be separate from
> the tribander
> and I can use
> > > both antennas at the same time with my SO2R setup.
> > >
> > > Here's the kicker. I will install the D40 above the
> A3S and want
> at least 10'
> > > of separation. In trying determine if I should align the D40
> with the A3S or
> > > offset it 90 degrees in azimuth, I have come up with a radical
> idea of
> > > installing a separate rotor above the A3S. My main
> rotor is the
> M2 RC2800. It
> > > will sit inside the top section. I will then install
> a piece of
> 2" aluminum
> > > conduit (mast) from the rotator up through my thrust
> bearing, but
> only sticking
> > > out of the tower a couple of feet. I will install the
> A3S here.
> On top of the
> > > conduit mast sticking a couple feet from the top of the tower,
> I'll install what
> > > will probably be a Yaesu G-450A with the mast mount (haven't
> purchased yet) and
> > > then a 10' piece of 2" aluminum conduit. Near the top
> of the 10'
> piece of
> > > conduit, I'll install the 18 lb D40. I've compiled the figures
> and the M2 is
> > > more than enough to rotate everything and the G-450A
> will handle
> the D40 with no
> > > problem. What I like about the G-450A is that it can be set to
> stop at any
> > > direction and shows an LED for overlap which I can set at 90
> degrees. Also,
> > > unlike the G-800S, you must push the left or right
> button to move
> it, so it
> > > won't rotate all the way around by itself. This is important
> because of the
> > > slack I'll need in the RF and rotor control cables from the D40
> and G-450A. The
> > > overlap LED will alert me that the D40 is offset. Keep in mind
> that the D40
> > > will only need to be rotated up to 90 degrees offset from the
> A3S, never any
> > > more than that.
> > >
> > > I've been thinking about this for weeks. I can't think for any
> reason why it
> > > wouldn't work. I hope to simulate the entire setup on the
> ground, possibly this
> > > weekend using an old CDE mast mounted rotator I have.
> Other than
> the G-450A, I
> > > have all the other hardware already. Has anyone ever heard of
> this setup
> > > before, a rotor on top of a rotor?
> > >
> > > By the way, updates on the towers on my new antenna page at
> > > http://www.aa5au.com/antennas/antennas.html
> > >
> > > 73, Don AA5AU
> > >
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