[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]
Re: Cheap Satellite Tracking (IR interface)
- Subject: Re: [amsat-bb] Cheap Satellite Tracking (IR interface)
- From: "Paul Willmott" <pwillmott@xxxxxxxxxxxx>
- Date: Sat, 27 Jan 2001 21:09:23 -0400
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
> > > > > >
> > > > > >
> > > > > > ----
> > > > > > 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
> > > >
> > > >
> > >
> > >
> > >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
> >
> >
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> >
> >
>
>
> 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
>
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
AMSAT Home