Hi Paul, KW7Y
To put a critical component like an electrolitic Bi-Polar capacitor inside the G-5500 rotator is a very bad idea from Yaesu because if the capacitor shorts out then it is necessary to dissable the antennas.
You are fortunate enought that your capacitor only looses capacity.
Much better is the old KR-500 with it's capacitor inside the control box.
By the way.....problem solved !
73" de
i8CVS Domenico
----- Original Message ----- From: "Paul Baldock" pbaldock@verizon.net To: "i8cvs" domenico.i8cvs@tin.it; amsat-bb@amsat.org Sent: Friday, December 11, 2009 2:06 AM Subject: Re: [amsat-bb] Re: G-5500 problem
I think I have confirmed that the problem is the motor capacitor. I have connected a 47uF Bi-Polar Cap across the motor connections in the shack, which is effectively across the 100uF up at the motor (unless a limit switch opens), and all seems to be working in both directions now.
- Paul
At 03:30 PM 12/10/2009, you wrote:
Thanks for your thoughts.
The current is about 2A when stuck or moving. (Same in both directions)
I can get it to move if I up the voltage a little with a series transformer. Nominal voltage is about 28V in the shack. By adding 10V it moves fine. So temporarily I will add a series voltage to "kick start" it, until the wx warms up and I can service the rotor.
Regards
- Paul KW7Y
At 01:31 PM 12/10/2009, you wrote:
Hi Paul, KW7Y
I suppose that you measure:
Between A6 and A4 for CCW = 4.4 ohm Between A6 and A5 for CW = 4.4 ohm
I suggest you to put an AC ammeter 5 Amps f.s. in series between the common terminal A6 of the control box and the wire coming up to A6 in the motor.
In this condition the AC current running CW or CCW must be about the same.
If the current increases when the motor stuks in CW position then there is a mechanical problem inside the rotator.
If the current is low when the motor stucks in CW position probably the capacitor C 35 losted capacity and if the current is zero probably the limit switch SW-7 inside the rotator is defective.
Unfortunately if the AC capacitor C35 = 100 uF AC wich is connected between A4 and A5 inside the rotator losted capacity you cannot measure its capacity from the shack.
The motor is a brusheless AC asyncronous motor using the starting capacitor C 35 to produce a 90° phase shift between both windings.
73" de
i8CVS Domenico
----- Original Message ----- From: "Paul Baldock" pbaldock@verizon.net To: amsat-bb@amsat.org Sent: Thursday, December 10, 2009 3:22 AM Subject: [amsat-bb] G-5500 problem
I have a G-5500 that sometimes will not turn clock wise(CW) but will turn counter clockwise (CCW) OK. When it is working OK in both directions each winding (CW and CCW) measures about 4.4 Ohms in the shack. When it will not turn CW that winding measures about 2.2 ohms (The CCW winding still measures 4.4 ohms).
The Controller is fine, so the problem is in the motor.
Does this motor have brushes?
Any thoughts on what the problem might be?
Thanks
- Paul KW7Y
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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