[SEDXC] FW: C.A.T.S. RD-1800 rotor

[John Harden, D.M.D.]

-----Original Message-----
From: John Harden, D.M.D. [mailto:jhdmd at bellsouth.net] 
Sent: Monday, February 13, 2006 8:30 AM
To: 'sedxc at contesting.com'
Subject: C.A.T.S. RD-1800 rotor
 
Dear Fellow DX-er's,
 
We have all had problems with rotators turning big arrays, and lasting
for any appreciable length of time. There is always the option of going
to Prop-Pitch motors made in the 1940's and 1950's by the Curtis-Wright
Corporation. However, most of these are not in great shape, and need
some work. Then there is the problem with direction indication that has
to be resolved. M-Square does make a control box for prop-pitch motors
if you don't homebrew your own. And, too, parts may have to be made in a
machine shop as they may not be available.
 
Two weekends ago my "depleted" Tail-Twister rotator was replaced again
with a rebuilt one. There was some wind and it did not last 24 hours.
However, I have upgraded the array on the 24 foot mast to a 6 el 15, 2
el full-sized 40 and a big M-Square rotateable 75/80 meter dipole (all
up over 100 feet). I finally ordered the RD-100 rotor from CATS, and
it's installation was completed in the darkness around 6:30 to 7:00 pm
last night. 
 
It works fantastic and utilizes a worm gear drive and a 20 VDC motor
turning at 1 RPM. It handles 25 square feet of antennas with around
TWICE the rotating torque of a Tail-Twister, and 1.5 times the braking
torque. The only one out there that outperforms it is the ORION at
$1600. However, there have been problems with the indication system on
it if you do not use shielded cable (RF issues). The price of the
HD-1800 is only $800 (without a control box) and this includes an
INTERFACE box for use with the Tail-Twister control box. It can be seen
at:
 
http://www.rotordoc.com <http://www.rotordoc.com/> 
 
I highly recommend it.
 
73,
 
John, W4NU
Atlanta