Mike,

I had a slightly related problem which turned out to be the phase shift capacitor in the rotator. You can see it on the schematic. The rotator would work fine with no load, and would generate more torque than you could stop with your hand. However, it would not move my array, which is admittedly overloaded. There was definitely a thermal effect here, in that on a cool day it would work a little, but not on a hot one. Replacing the capacitor solved the problem, but it was messy. If they just plugged it in but did not test it under a real load, they MIGHT have missed a problem. My experience with Yaesu/Vertex techs is that they are either excellent, or incompetent, with little in between.

If you can find a good capacitor, you can bridge the lines at the control box end in parallel with the rotator unit. If it works, or works better, that is a good indication of a bad internal capacitor.

Alan WA4SCA

-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Michael J. Wolthuis Sent: 22 November, 2009 19:07 To: Elan Portnoy Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: Help with Yaesu g5500

Not the switch unfortunately. The same problem occurs when controlled by computer from Uni_trac 2000. Work about 25% of the time.

Mike kb8zgl

Elan Portnoy wrote:

Spray-out the switch with cleaner?

--- On Fri, 11/20/09, wolthui3@msu.edu wolthui3@msu.edu wrote:

...

From: wolthui3@msu.edu wolthui3@msu.edu Subject: [amsat-bb] Help with Yaesu g5500 To: amsat-bb@amsat.org Date: Friday, November 20, 2009, 11:12 PM I bought a used Yaesu g5500 and it has a strange problem. The AZ works perfect, but when I push the EL button it seems to work (ie. Move up or down) about 1 out of 4 tries. I can regularly duplicate the issue where I can't get EL to change. If I wait 30mins and come back then it sometimes works right away.

The rotor itself was into Yaesu and they said it was 100% perfectly fine. I have tried swapping the AZ/EL cables around and no difference.

It has to be a controller issue I think. Any ideas before I box it up and ship it to Yaesu to check?

When it works, it works fine and typically for 5-10mins straight, but then suddenly it will not change again.

Mike kb8zgl _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

---

Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

_______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

----- Original Message ----- From: "Michael J. Wolthuis" wolthui3@msu.edu To: "Elan Portnoy" elanportnoy@yahoo.com Cc: amsat-bb@amsat.org Sent: Monday, November 23, 2009 2:07 AM Subject: [amsat-bb] Re: Help with Yaesu g5500

Not the switch unfortunately. The same problem occurs when controlled by computer from Uni_trac 2000. Work about 25% of the time.

Mike kb8zgl

Hi Mike, KB8ZGL

Connect an AC voltmeter between A4 and A5 on rear of control box and check if there is 24 volt AC when the rotator sticks.

If you have 24 volts when the rotator sticks connect an amperometer in series with A4 or with A5 and check if the AC current flows as soon the rotator sticks.

If the current flows when the rotator sticks probably the internal AC 100 uF capacitor is defective or you have a mechanical problem inside the reduction gear or into the ball bearing holder of your rotator

If you have a 100 uF AC capacitor in the junk box connect it across A4 and A5 and try again to see the effect.

If you don't have an AC capacitor you can buit it by your self using two electrolitic capacitors each 200 uF 250 volt DC and two diode 1N4007 or equivalent connected as per the following schematic diagram:

- + + - |--------) |------|------| (--------| A4-----| | |-------A5 |-------|>|------|------|<|--------| 1N4007 1N4007

If the rotator sticks and if the AC current don't flow you probably have e limit switch SW6 or SW7 defective "poor contact and high resistivity" between contacts.

Disconnect A4 and A5 from control box and using an ohm-meter check the continuity of the motor windings

If one winding of the motor has a fail contact then your ohm-meter will jump measuring the capacity of the AC capacitor.

This is what I would do easy and fast in your situation.

Have fun

73" de

i8CVS Domenico