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Re: Cheap Satellite Tracking (IR interface)



Does it track expensive satellites as well?
----- Original Message -----
From: "Jim Sullivan" <sja6@qwest.net>
To: <AMSAT-BB@AMSAT.Org>
Sent: Saturday, January 27, 2001 10:15
Subject: Re: [amsat-bb] Cheap Satellite Tracking (IR interface)


> Yes the three-wire connection rotor. The original controller uses a
> syncronous motor, like a clock motor, to match rotation speed with
> the rotor's motor. The electronic version must count AC zero
> crossing to provide control (I'm guessing here).
>
> Resyncing the rotor is needed just like with the original controller.
>
> Jim Sullivan
>
> On 26 Jan 2001, at 11:05, Doug Braun NA1DB wrote:
>
>  > This works with the RS rotor that uses a three-wire connection
>  > (with an AC motor and no position feedback)?
>  >
>  > Thanks,
>  >
>  > Doug
>  > NA1DB
>  >
>  > At 07:26 AM 1/25/01 , you wrote:
>  > >I am using the IR remote with a RS rotor. Fry's Electronics has the
>  > >remote setup for $45. It uses a wall-wart power supply and a small
>  > >control head. It has 3 large red LEDs, holds 99 positions in
>  > >memory. The accuracy and repeatability are about the same as the
>  > >original controller.
>  > >
>  > >The handheld remote unit has a numerical keypad for entering
>  > >direct azimuth, memory positions and up/down buttons for slewing.
>  > >The display updates as the rotor slews..
>  > >
>  > >I've been using it six months for my terrestrial VHF beams.
>  > >
>  > >Jim N7TCF
>  > >
>  > >On 24 Jan 2001, at 8:55, Douglas NA1DB wrote:
>  > >
>  > >  > Hello,
>  > >  >
>  > >  > Have you actually seen are used this remote control thing?
>  > >  > Does it completely replace the manual control box?
>  > >  >
>  > >  > Thanks,
>  > >  >
>  > >  > Doug
>  > >  > NA1DB
>  > >  >
>  > >  > At 06:31 PM 1/23/01 , you wrote:
>  > >  > >I will certainly be interested!
>  > >  > >
>  > >  > >Are you aware of the IR remote system for this rotor? I've been
>  > >  > >thinking of hacking it for computer control.
>  > >  > >
>  > >  > >Jim Sullivan N7TCF
>  > >  > >
>  > >  > >On 23 Jan 2001, at 13:55, Bob Bruninga wrote:
>  > >  > >
>  > >  > >  > I'm working on a $20 printer port interface to the Radio
Shack $64 Antenna
>  > >  > >  > Rotator to simplify tracking and monitoring the digital and
FM birds.
>  > >  > >  > While not suitable for a high-gain OSCAR class station, this
will let
>  > >  > >  > anyone with a dual-band FM rig operate via at least a dozen
of the amateur
>  > >  > >  > digital and FM voice satellites at low cost.
>  > >  > >  >
>  > >  > >  > Taking advantage of the geometry of low earth orbiting
satellites, you can
>  > >  > >  > cover 96% of all access times with over 10 dB gain using only
a fixed
>  > >  > >  > 10 deg elevation and a short 4 to 6 element UHF beam.  Here
is why:
>  > >  > >  >  * 4-6 elements is enough gain to be above digital threshold
>  > >  > >  >  * 4-6 elements is enough to be above FM threshold for voice
>  > >  > >  >  * Most LEO birds are mostly vertical most of the time.
>  > >  > >  >  * LEO satellites are below 45 degrees for 95% of the time
>  > >  > >  >  * The other 5% of the time, they are 6 to 10 dB closer in
range
>  > >  > >  >
>  > >  > >  > Here is a plot of overall gain for the elevation angles
shown.  Notice
>  > >  > >  > the cumulative percent column showing 96% of all pass times
are below 50
>  > >  > >  > degrees yet still give you at least 10 dB gain on the bird.
>  > >  > >  >
>  > >  > >  > EL  PCT CUM-% RANGE RNG-GAIN ANT-GAIN OVERALL-GAIN
>  > >  > >  > --- --- ----- ----- -------- -------- ------------
>  > >  > >  > 10   32   32  3030     0       10         10
>  > >  > >  > 20   35   67  2440     2       10         12
>  > >  > >  > 30   17   84  1827     5        8         13
>  > >  > >  > 40    8   92  1460     6        6         12
>  > >  > >  > 50    4   96  1190     8        2         10
>  > >  > >  > 60    2   98  1020    10        0         10
>  > >  > >  >
>  > >  > >  > * Data for an 800 km orbit.  For the ISS at 370 km, the times
below 30
>  > >  > >  > degrees are even 6% higher than shown.
>  > >  > >  >
>  > >  > >  > Note:  If your horizon is blocked below say 5 degrees anyway,
then
>  > >  > >  > elevate the beam to 20 deg to improve gain (+2 dB) for
everything else.
>  > >  > >  >
>  > >  > >  > The interface is built on a small perf board and placed
inside the rotator
>  > >  > >  > housing with a small wire coming over to your  PC printer
port.  APRStk
>  > >  > >  > will have the software drivers.  The software uses the fixed
RPM timing to
>  > >  > >  > keep track of the beam and it will auto-re-sync periodically.
ALso, the
>  > >  > >  > original control/indicator can still be used for manual
pointing.
>  > >  > >  >
>  > >  > >  > Other typical 24 volt AC rotators without indicator circuits
can be used.
>  > >  > >  >
>  > >  > >  > de WB4APR@amsat.org, Bob
>  > >  > >  >
>  > >  > >  > See my APRS LIVE pages
http://web.usna.navy.mil/~bruninga/aprs.html
>  > >  > >  > See APRS SATELLITES
http://web.usna.navy.mil/~bruninga/astars.html
>  > >  > >  > See MIM/Mic-E/Mic-Lite
http://www.toad.net/~wclement/mim2.htm
>  > >  > >  >
>  > >  > >  >
>  > >  > >  > ----
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AMSAT-NA.
>  > >  > >  > To unsubscribe, send "unsubscribe amsat-bb" to
Majordomo@amsat.org
>  > >  > >  >
>  > >  > >
>  > >  > >
>  > >  > >Jim Sullivan
>  > >  > >
>  > >  > >----
>  > >  > >Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>  > >  > >To unsubscribe, send "unsubscribe amsat-bb" to
Majordomo@amsat.org
>  > >  >
>  > >  >
>  > >
>  > >
>  > >Jim Sullivan
>  > >
>  > >----
>  > >Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>  > >To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>  >
>  >
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>  >
>  >
>
>
> Jim Sullivan
>
> ----
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>

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