[amsat-bb] Re: Motor for Yaesu G5500 Azimuth Rotator?

[Phil Karn]

On 2/26/12 3:02 AM, i8cvs wrote:

> 
> If you are interested in a very simple but effective "Single to 3-PHASE
> Power Converter for azimuth and elevation motors currently used for
> EME, look at this web page made by John Yurek, K3PGP
> 
> http://www.k3pgp.org/3phconv.htm

This is a classic "rotary phase converter" that uses a surplus 3-phase
'idler' motor to generate something resembling 3-phase AC from a single
phase utility supply. The idler motor itself needs a starting mechanism;
this one seems to do it with running capacitors but I've also seen it
done with a separate single-phase starting motor.

These things are commonly homebrewed to run 3-phase machine shop tools
when a 3-phase utility feed isn't available. They usually work well
enough, but the output is not ideal 3-phase AC.

It's also fixed frequency. A variable frequency supply is what you
really want when driving antennas.