Hy Tyler, KI4YLJ

I use a 0-360° protractor for the AZ and a 0-90° protractor for the EL for my manual traking system used for several years in 432 MHz EME and AO40

The moving needle in the center of the protractor is mounted on the shaft of a Selsyn motor receiver wich is fitted in the control box while the Selsyn motor transmitter is mechanically coupled to the moving shaft of the antenna.

Only 5 wires are necessary to connect a Selsyn transmitter to a Selsyn receiver.

Three wires are needed to connect in parallel S1-S2-S3 of both stators and two wires are needed to connect in parallel R1 and R2 of both rotors while in general a 115 volt AC 50 or 60 Hz depending on the model is supplied to R1 and R2

Depending on the size and torque of Selsyn motors it is possible to move a long needle for high accuracy as about 1/2 degrees as in my case using a 15 cm long needle mounted over the shaft of a 2" Muirhead Selsyn motors originally used to point marine guns on battle-ships during the WWII

Using an integrated circuit AD2S80 from the Analog Device it is actually possible to make the conversion Syncro to Digital showing the angular position in digital form and get out as well a 0 to 5 volt DC to be used for the automatic antenna traking with a computer and this is what I plan to do as soon as possible.

In a separate email I will send to you some pics of my actual manual control box showing the schematic diagram and the type of Selsyn motors that I have used.

Selsyn motors of different type and different voltages are actually available as new or as used at a really low cost on ebay.

73" de

i8CVS Domenico

----- Original Message ----- From: "Tyler J Doering" tyler.doering@gmail.com To: "'Doug Faunt N6TQS +1-510-655-8604'" faunt@panix.com; amsat-bb@amsat.org Sent: Tuesday, August 19, 2008 8:27 PM Subject: [amsat-bb] Re: Wanted, printable,scalable clockwise protractor image

Doug:

Here is a simple pdf 48x36 that I have used in the past to help track

LEO's.

Linked here as well: http://www.cslab.uky.edu/~tjdoer2/drop/080719%20-%20Degree%20Marking.pdf

Thanks

Tyler, KI4YLJ

-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Doug Faunt N6TQS +1-510-655-8604 Sent: Tuesday, August 19, 2008 1:42 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Wanted, printable, scalable clockwise protractor image

Hi all, I think it'd be easier for me to manually track LEO's if I had a image

like

this one, but with the numbers clockwise. Any help?

http://www.mathsisfun.com/geometry/images/degrees-360.gif

73, doug

Thanks much. That's a great resource.

73, doug

From: n1jez@burlingtontelecom.net Date: Fri, 22 Aug 2008 06:00:26 -0400

Hi Doug,

We use these a lot for microwave operation. Check out:

http://www.oregonruleco.com/dials.htm

73, Mike N1JEZ AMSAT #29649 "A closed mouth gathers no feet"

-----Original Message----- Subject: [amsat-bb] Wanted, printable, scalable clockwise protractor image

Hi all, I think it'd be easier for me to manually track LEO's if I had a image

like

this one, but with the numbers clockwise. Any help?

http://www.mathsisfun.com/geometry/images/degrees-360.gif

73, doug