[amsat-bb] Re: Playing With Lightning

i8cvs domenico.i8cvs at tin.it
Sat Mar 13 16:20:43 PST 2010

----- Original Message -----
From: "Joel Black" <jbblack68 at gmail.com>
Cc: "'AMSAT'" <amsat-bb at amsat.org>
Sent: Saturday, March 13, 2010 10:44 PM
Subject: [amsat-bb] Playing With Lightning

> I certainly appreciate all the replies and the encouragement.
> If any of you with a G-5400 controller would check something out, I'd
> appreciate it.  When I move up or right, there is a momentary deflection
> in the opposite direction.  Then, when I release the button, it jumps
> ahead a bit by just a few degrees.  If I move down or left, there is no
> immediate deflection, but when I release the button, it deflects in the
> opposite direction.  I just don't remember mine acting that way before
> the strike.
> Thanks,
> Joel, W4JBB
Hi Joel, W4JBB

Trouble-shooting for your G-5400

I suggest you to momentarily disconnect the wires A1-A2-A3 going from
the rear of the control box up to the rotator.

Connect  temporarely for test a 500 ohm wire wound potentiometer to
terminals A1-A2-A3 of the control box taking into account that A2 is the
wiper of the potentiometer.

Power supply the control box and rotate very slowly by hand the shaft of
the potentiometer.

If the pointer of the azimut instrument follows accordingly your rotation
by hand than there is no damage into the control box.

Repeate the same procedure for the wires E1-E2-E3 to test the elevation
remembering that E2 is the wiper of the potentiometer.

If the pointer of the elevation instrument follows accordingly your by hand
rotation of the potentiometer then there is no damage into the control box.

If  the deflection of the instruments is still like you describes probably
the integrated circuits C3 and C4 into the control box where damaged by
the strike.

Reconnect the original wires between the rotator and the control box and
using a high impedance DC voltmeter measure the voltage between A2-A3
and E2-E3

While rotating the antennas left and righ and up and down  observe if the
voltage follows  smootly the above rotation.

If the voltage jumps there is probably a damage into the potentiometer
wipers inside the rotator

Check if the voltage between A1- A3 and between E1-E3 is about 6 volts.

The voltage must remain constant at about 6 volts rotating the antennas
othervise the voltage regulator Q2 was damaged by the strike.

Using the above trouble-shooting you can establish if the problem is located
into the rotator or into the  controlbox or along the wires connecting both.

Have fun !

Best 73" de

i8CVS Domenico

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