Re: [amsat-bb] Cheap Satellite Tracking

["Jim Sullivan" <sja6@xxxxxxxxx>]

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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 > >  > 
 > >
 > >
 > >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

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