[amsat-bb] Re: G5400B Rotor Problem

i8cvs domenico.i8cvs at tin.it
Thu Nov 29 11:22:52 PST 2012

---- Original Message -----
From: "John Wright" <ham at g4dmf.co.uk>
To: <amsat-bb at amsat.org>
Sent: Thursday, November 29, 2012 5:40 PM
Subject: [amsat-bb] Re: G5400B Rotor Problem

> At 21:00 28/11/2012, you wrote:
> >Got some unexpected time today to look at the rotor. First I set the
> >output at pin 6 of the external control output jack to 5.0 V. Then I
> >got readings every 45 deg from 180 at the left to 180 on the right.
> >The readings are of course subject to parallax in reading the
> >needle. Readings from 180 on the left to 180 on the right were
> >0.024, 0.606, 1.270, 1.864, 2.489, 3.074, 3.690, 4.350, and 5.000 V.
>
>
> Draw a graph of AZ vs Voltage... It should be a straight line, if
> not, the pot is not linear!
>
Hi John, G4DMF

I agree with you and draw a graph of AZ versus Voltage to see if it is
or not a straight line is a very good idea but you don't want to read
the AZ on the control-box meter because the meter can be not linear.

BTW the idea to read the AZ as Erich DK1TB did is to me the best
procedure.

In a previous message on Amsat-BB Erich  writes :

----- Original Message -----
From: "Erich Eichmann" <erich.eichmann at t-online.de>
To: <tokens at myranch.com>
Cc: <amsat-bb at amsat.org>
Sent: Thursday, November 29, 2012 7:52 AM
Subject: [amsat-bb] Re: az-rotor

< snip>

I mounted the  KR-600X in the shack over a big 360° linear scale with 1 m
diameter and with a pointer that moved around the scale close above it. The
rotor ran exactly an 360° turn from the starting position  180° in the south
to the end position 180°.

--------------------------------------------------
73" de

i8CVS Domenico