[TowerTalk] Re:

W4EF@dellroy.com W4EF@dellroy.com" <W4EF@earthlink.net
Mon, 4 Sep 2000 11:52:06 -0700


Hi R,

The +/- 14 degree spec on the OR-2800 isn't meant to be a tolerance on the rotational
range of the rotator. What it means is that the rotational range of the rotator is 388
degrees. In other words when you setup for a north stop, the rotator will swing from
346 degrees azimuth thru due north, all the way around clockwise thru due north again,
and then stop at +14 degrees azimuth. I think this is done to eliminate the possibility of
any dead zones near the stops when using large (very narrow beamwidth) VHF/UHF
arrays (the designer of the rotator is a big EME guy).

Also, if you are planning to use the rotator inside a Rohn 25G straight section, be
prepared to cut one diaganol brace and bend the other two just slightly. The OR-2800
will fit, but its really tight. Dunno about the Yaesu, as I don't have much experience
with it.

Mike,
W4EF................................................................................................................................

----- Original Message -----
From: "R. Otto" <N8NGA@one.net>
To: <towertalk@contesting.com>
Sent: Monday, September 04, 2000 8:11 AM


>
> Hello towertalk,
>
> We're back to one of those "how do ya tell" questions.  Based on the
> input here (which was pretty diverse) I went to the sites for several
> rotors to compare specs.  Rotors, just like antennas, have no standard
> of comparison.  Each company has it's own gobbledygook of marketing.
> For instance, how do you compare the following??
>
> Orion 2800  -
> Wind Area Capacity            35 sq. ft.
> Starting Torque               3500 in. lbs.
> Rotating Torque               2800 in. lbs.
> Braking Torque                17,000
> Vertical Load Capacity        1800 lbs
> Mast Size (OD)                1.75-3"
> Rotation Speeds / 360 degrees 55 TO 300 sec.
> Rotation Range                0-360 degrees -+ 14 degrees
> Weight (rotator unit)         42 lbs.
>
> Cost                          $1429 with controller
>
> Yaesu G2800SDX -
> Wind Load                     23.5 Sq. Ft.
> K-Factor                      2,020 Ft.-Lbs.
> Stationary Torque             433 Ft.-Lbs.
> Rotation Torque               43-79 Ft.-Lbs.
> Max. Vert. Load               440 Lbs.
> Max. Vert. Intermittent Load  1320 Lbs.
> Mast Size                     1-1/2 - 2-1/2 In.
> Backlash                      ± 2°
> 360° Rotation Time            35-74 Seconds
> Weight                        7.7 Lbs.
> Cable Conductors              5
>
> Cost                          $1069
>
> Couple of observations.  If I convert Yaesu's ft/lb to
> in/lb by multiplying by 12, the Yaesu still comes out quite a bit on the short end
> of the stick.  Interesting that the Orion has a 360 degree rotation,
> +/- 14 degrees.  Seems to me that's not very good.  Theoretically it
> could be 15 degrees short, when I'd really like to see over 360
> degrees so I can quickly hit that station that always seems to be just
> the other side of the mark requiring a 350 degree rotation <G>.
>
>
> I've tried to find the "Prop Pitch" rotor and had no success.  Same
> with Aztec RF.   Any ideas?
>
> 73's from....
>
> R. Otto
> N8NGA@one.net
> Cincinnati, Ohio
>
> **********************************************
> DXCC 10M         ** DX Is !! **        WAS 10M
>        There is a very fine line between
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