In my opinion, you dont need elevation for any existing AMSAT nor do you need an OSCAR array since we have no HEO birds and LEO's are so close, there is 6 to 10 dB right there.  And with nmodest beams, the beamwidth is wider than the inaccuracy in the rotator.  My design simply used the 1 RPM rotatino of the motor to keep track of position and after each pass, or on edmand, it woiuld drive CW (or CCW) into the stops, zero the counter and then consider that zero and count from there.  Tilt the beams up modestly to 15 degrees and you have plenty of gain.   When the LEO satellite is above that it is 6 to 10 dB closer and plenty strong enough.  And when it is below 15 degrees it is far away on the horizon and still totally within the main beam of the modest beam.
Bob, WB4APR

On Sat, Mar 6, 2021 at 9:36 PM Greg D <ko6th.greg@gmail.com> wrote:
Some rotors use a microswitch feedback system, where there is a momentary "click" every few degrees.? It's pretty easy to build a system that counts clicks and controls a set of relays based on it.? I did this 20 years ago with a Basic Stamp-II.? Should be fairly trivial to port to an Arduino, especially since you wouldn't have to deal with a 360 degree coordinate system in a system that was limited to mostly 8 bit math due to a lack of variable space.? That was fun...? See http://home.wavecable.com/~ko6th/ at the top of the page.? (Yeah, the site desperately needs an update...? The current software version is 1.4.)

The rotors I used had a resolution of 6 degrees for Azimuth, and 10 degrees for Elevation, which is well within the beamwidth of the antennas.?

Greg? KO6TH


Russ Ramirez wrote:
Tim, I had some success with this with an Alliance Tenna rotor a few years ago, but the older (Arduino Mega based) K3NG rotator controller would "hunt" in terms of Elevation because these old rotors generally do not have position feedback in the form of a potentiometer the way the Yaesu rotors do. The G-5500(DC) setup is hard to beat.?

Good luck!?
Russ
K0WFS


On Sat, Mar 6, 2021 at 6:18 PM Timothy Tapio <timothytapio1@gmail.com> wrote:
Anyone have a simple interface for a low budget TV rotor (RCA) to allow SatPC32 to control azimuth? I do have intentions of obtaining a GS-5500 but that is a few months down the road....meanwhile I have an Alaskan Arrow still in box that I want to use until I can get the sat antenna pack from Amsat....

Any Raspberry Pi or Arduino interfaces? It's beyond my level to try to program something myself.



-----------------------------------------------------------

Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!

View archives of this mailing list at
https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org
To unsubscribe send an email to amsat-bb-leave(a)amsat.org
Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org


-----------------------------------------------------------

Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!

View archives of this mailing list at
https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org
To unsubscribe send an email to amsat-bb-leave(a)amsat.org
Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org


-----------------------------------------------------------

Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!

View archives of this mailing list at
https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org
To unsubscribe send an email to amsat-bb-leave(a)amsat.org
Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org