[amsat-bb] Re: G5500 Elevation Rotator Short Circuit?

[n8deu]

Most of the motors I repaired did not have the limit switches because they 
were early models. There was one the limit switch was broken and another 
that had limit switches that I could only attribute to excessive use that 
overheated and the windings to the point that the enamel broke down (of 
course, with no certainty). Lightning strikes were much easier to see.

Some of the early Kenpro units did not employ the protective limit switches.

The Kenpro KR-5400 did not have limit switches in either the azimuth or 
elevation rotors.
The Kenpro KR-5600 employed limit switches only on the Azimuth rotor.
The Yaesu G-5400 employed limit switches only on the Elevation and employed 
a thermal switch on the Azimuth rotor.
The Yaesu G-5600 employed limit switches on both the Elevation and Azimuth 
rotor.

The Kenpro KR-5400 and 5400 employed the motor capacitors in the control 
box.
The Yaesu G-5400 moved only the Elevation motor capacitor to the rotor, but 
left the Azimuth motor capacitor in the control box.
The Yaesu G-5600 moved both motor capacitors from the control box to the 
Elevation and Azimuth rotors.

During Field Day when I had to swap from a Yaesu to Kenpro controller I had 
to utilize jumpers to add the 100uF capacitor to make the Kenpro Azimuth 
motor work. Everybody looked at this black plastic capacitor I jumpered on 
the back of the control box and I just told them it was my Flux Capacitor 
until some Engineer requested an explanation for its purpose.



73's,
Tim - N8DEU


----- Original Message ----- 
From: "Clive Wallis" <list1 at g3cwv.co.uk>
To: "Tim Cunningham" <n8deu at att.net>; "amsat" <amsat-bb at amsat.org>
Sent: Sunday, October 16, 2011 5:52 AM
Subject: Re: G5500 Elevation Rotator Short Circuit?


> Thanks Tim.
>
> I'm not aware of any problems with my controller or computer. I notice 
> that there are micro switches to protect against over-run, and wonder why 
> these didn't protect the motor, if one of the circuits had stuck on.
>
> BTW  have there been any improvements with the sealing against rain water 
> on this model? It seems better than the previous model, in this respect.
>
> 73    Clive    G3CWV
>
> On 13/10/2011 21:46, Tim Cunningham wrote:
>> All of the failures were specifically attributed to either a stuck relay
>> in the control box, a manual switch sticking (not releasing) on the
>> front rotor control panel, and a software or computer crash that
>> continued to drive one of the up, down, left, or right control lines.
>>
>>
>> 73,
>>
>> Tim - N8DEU
>>
>>
>> ----- Original Message ----- From: "Clive Wallis"
>> To: "amsat" <amsat-bb at amsat.org>
>> Sent: Sunday, October 09, 2011 11:50 AM
>> Subject: [amsat-bb] Re: G5500 Elevation Rotator Short Circuit?
>>
>>
>> Many thanks Tim for your comments. From what you've said it sounds like
>> a faulty motor. In the ones you've repaired have you been able to
>> determine the cause of motor over heating?
>>
>> The problems I've had in the past have always been due to water getting
>> into the units.
>>
>> 73 Clive G3CWV
>>
>> Hitchin, North Hertfordshire, UK
>>