[amsat-bb] Re: G-5500 rotor motor intermittent

Sat Jun 20 19:26:33 PDT 2009

Thanks Alan, 

Stan, W1LE just e-mailed me direct, but will share with the group as well
some additional corrections... and, there is no thread to follow, this is
the first post...

My gut suspicion is that there is a damaged or intermittent limit switch
and/or position wiper.  But I forgot I could swap the connectors at the
rotor and I will try this, great idea, just in case the cable got torqued in
the storms.  A few observations,

1.)  Controller:  I opened the wires and put molex so I can detach and debug
easily.  Controller appears fine.  Using the molex approach, I switched Azi
and Ele and the symptoms moved.  The meter indicator is not intermittent.
The Azi, it is at 0, no motion.  Ele works fine.  

2.)  Rotor:  I have the rotor up on top of the chimney and then another 12
feet higher because of high trees all over and to clear the chimney itself.
A superficial inspection yields little.  

On Ele:  impedance from 4 or 5 to 6 both 2-3 ohms including 120 feet of
cable, impressive.  From 1-3 508 ohms and 2-3 504 ohms and 1-2 4 ohms

On Azi:  impedance from 4 or 5 to 6 both open.  From 1-3 368 ohms and 2-3, 0
ohms and 1-2 367ohms

Michael  K3MH

-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of Alan VE4YZ
Sent: Saturday, June 20, 2009 6:47 PM
To: 'Michael Hatzakis Jr MD'; amsat-bb at amsat.org
Subject: [amsat-bb] Re: G-5500 rotor motor intermittent

"and the Ele was near 2-3 ohms and the Ele was open." 

Michael I believe you have a typo and mean the AZ was open?

I have not followed this entire thread so I don't specifically know what the
"intermittent" part means.   Random failures regardless of the position of
the rotator or failures at nearly the same rotator position?

Before bringing down the rotators, reseat the connectors at the rotator and
inspect for corrosion on the contacts.  Also while you are up at the
rotators check your loop of cables that they are not stressed as they coil
and uncoil during rotation and are not putting strain on the connectors.
You can also open and inspect the connector.

This is not a solution for your issues but rather just some observations.

The beauty of the G5500 is that both EL and AZ rotators have limit switches
and the phasing capacitors are in each rotator.  So you can swap the cables
at the controller from AZ to EL to see if the problem moves with the cables.
If it does not, then the issue would be within the controller.

If you swapping the connectors at the rotators and see if the problem move
to the other rotator it would indicate cable or connector ( male ) problems.

For those with  the G5400 life is more complicated as the capacitor for the
AZ rotator is in the rotator but the EL capacitor is in the controller box.
Worse, the EL is the only one with limit switches ( AZ has thermal overload
) and neither of the rotators have that nice quick connector but rather the
terminal strip. Ya, and it goes 450 degrees AZ instead of 360.  So you CAN
NOT SWAP cables to trouble shoot a GB5400B combo!

-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of Michael Hatzakis Jr MD
Sent: June 20, 2009 7:54 PM
To: amsat-bb at amsat.org
Subject: [amsat-bb] Re: G-5500 rotor motor intermittent

Ok, sorry for the additional post, this is a follow up.  After my debugging
session today, I am fast-forwarding to what I expect will be the ending to
this little fairy tail, that is, I see me climbing up and pulling down this
damn rotor to either replace or repair.  

So, next natural question is, if I am going to repair, what should I repair
while I have it open or are there people who do a good job in rebuilding
Yaesu rotors, roughly 5 years old??

Michael  K3MH

-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of Michael Hatzakis Jr MD
Sent: Saturday, June 20, 2009 5:41 PM
To: 'Angelo Glorioso'; glasbrenner at mindspring.com
Cc: amsat-bb at amsat.org
Subject: [amsat-bb] G-5500 rotor motor intermittent

Andrew and group,

Read this post and others about the 5500, and I am trying to figure out what
do with my rotor or my controller.  

My rotor has become more and more intermittent over time, so I opened up my
cables and put molex connectors in line so I can debug.  I started with
impedance of the rotor.  My Elevation is working now and my rotation is not.
I pulled out the schematic and see that the rotor motor is on 4-5-6 with the
common on 6 each and the up/down or left/right on 4-5.  I measured the
impedance of 4 & 5 against 6, and the Ele was near 2-3 ohms and the Ele was
open.  I am wondering if this is an intermittent internal limit switch?
Taking my rotor apart is a huge deal, so I want to be sure I am looking at
this situation correctly and what else should I be looking for or measuring?

Michael  K3MH

-----Original Message-----
From: owner-AMSAT-BB at amsat.org [mailto:owner-AMSAT-BB at amsat.org] On Behalf
Of Angelo Glorioso
Sent: Monday, March 28, 2005 8:21 AM
To: glasbrenner at mindspring.com
Cc: amsat-bb at amsat.org
Subject: RE: [amsat-bb] G-5500 rotor motor woes

Hi  Drew,

 At least you got 3 years out of yours. I had my G-500 a month before the
motor went out and had to send it to Yaesu.

 Everything was balance as well. What I think happened is one of the buttons
on the control box got stuck in one direction and caused the motor to burn
up.

 What I did was change the fuse that Yaesu uses from a 2 amp AGC to a 1 amp
slow blow fuse. Just in case this happens again, at least the fuse will blow
before causing the motor to go out. 

73 de Angelo

---------------------------------------------------------

If you don't ask, you will never know!! >From: Andrew Glasbrenner
<glasbrenner at mindspring.com> >Reply-To: Andrew Glasbrenner
<glasbrenner at mindspring.com> >To: amsat-bb at amsat.org >Subject: [amsat-bb]
G-5500 rotor motor woes >Date: Mon, 28 Mar 2005 09:20:31 -0500
(GMT-05:00) > >About 3 weeks ago my azimuth rotor motor bit the dust. The
rotor turned left fine, but not right. I tore into the unit and found the
windings on the motor to show 4 ohms in one direction, and only 1.5 in the
other. Yaesu wanted about $90 and shipping  for a replacement, but I found a
G-450 locally for about the same money. After swapping the motors
(identical) and reassembling it seems to work fine, but I can find no reason
for the failure. > >Anyone been down this road before and have some hints?
I'd rather not repeat this procedure in a few weeks. I also expect longer
service from a 3 yr old rotor that cost almost $600. The inside was dry, and
well greased. I don't think it's overloaded either, with a M2 436cp30,
Cushcraft 10x10 2m, and 3ft S band dish near the center, all well balanced.
> >73, Drew KO4MA > >PS Anyone got a spare motor for my 450? Or need a 450
control box and parts? ;-) >---- >Sent via amsat-bb at amsat.org. Opinions
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