[amsat-bb] Re: Yaesu 5500 rotor problem

i8cvs domenico.i8cvs at tin.it
Thu Jul 12 05:01:24 PDT 2007

Hi Jeff, KB2M

Despite the problem on your shoulder you can locate the fault on your
azimuth control and display just from the shak.

Without disconnecting any wire from the back of your control box connect
a DC voltmeter between terminals A1 and A3 and you should read about
5.5 volt DC

Connect the DC voltmeter between terminals A2 and A3

When the antenna is rotated fully CCW you should read 0 volt and rotating
the antenna by 360° CW the voltage should linearly increase up to about
5.5 volt

If you pass the above test than the 500 ohm potentiometer inside the rotator
is OK

If not or the potentiometer is gone or one of the wires A1-A2-A3 running
from the control box to the antenna is interrupded.

To test if the control box alone is OK or not disconnect wires A1-A2-A3 from
the rear of control box and connect to it a 500 ohm wire wound potentiometer
to simulate the potentiometer inside the rotator.

Manually turning the above potentiometer you should have the angular
position information of the pot wiper (A2 wire) both on control box meter
and PC software.

Have fun !

73" de

i8CVS Domenico

----- Original Message -----
From: "Jeff Griffin" <kb2m at comcast.net>
To: "Amsat-Bb" <amsat-bb at amsat.org>
Sent: Wednesday, July 11, 2007 3:01 PM
Subject: [amsat-bb] Yaesu 5500 rotor problem

> I'm having a problem with my 5500-azimuth display and control. I haven't
> used it in a few weeks, tried to work some passes last night and
> that I lost azimuth control and display. Big problem here is that I had an
> operation on my shoulder on July 6th and have the use of my left arm only.
> So I thought I would ask here to try and streamline the repair process.
> are the symptoms...
> Elevation works fine in manual or computer control.
> Azimuth works in manual mode, but no location information is displayed on
> control unit or pc software. Also no computer steering , only way to turn
> manual input , but no position display.
> I tried to tweak the azimuth pots, no joy. Was thinking possible dead
> Any useful info would be appreciated. Sometimes I wonder if I hit bottom
> in this worst year of my life...
> 73 Jeff kb2m

More information about the AMSAT-BB mailing list