Hi Randy - Comments and suggestions interspersed below.
At 06:53 PM 12/16/2008, Randy Hollingsworth wrote:
>I recently installed a Yaesu G1000-DXA rotor on my tower. I constructed the
>control cable per the Yaesu manual instructions, and against my better
>judgment, crimped, but did not solder, the pins for the molex style
>connector on the rotor control box. Sure enough, within a month, the wires
>pulled out of a couple of the crimped connector pins. I obtained a new
>connector and cable (commercially manufactured) and installed it, but now
>the rotor will not operate at all. The pilot lights are on in the control
>box, but when you push the CW or CCW switch, nothing happens. I checked the
>cable thoroughly before installing and all the connector connections are
>correct. In addition, I checked the resistances through to the rotor and
>they too seem reasonable. The two pins that go to the ends of the
>potentiometer in the rotor read a bit over 500 ohms, while the center tap on
>the pot will read about 300 ohms one side, 200 on the other. The pins that
>run to the filter and motor read about 13 ohms, which seems reasonable,
>although I do not know if that is simply the motor winding turns or a more
>complex value.
Your readings from the rotator are about right. The most important thing
is that you have continuity on the pot and the motor. So, we can assume
that the rotator is OK.
>
>
>At any rate, this seems to point back at the control box, although it is
>only a year old and was only in use for the month before the connector wires
>pulled out. I found K1TTT's article on checking Yaesu GXXXX-DXA rotors and
>tried to follow it to remove the control box cover, but his description of
>the locations of the screws to remove do not match up with my controller, so
>did not want to proceed until I was able to find a source that better fit my
>unit. Unfortunately, the info available on the web about checking these
>units is pretty sparse.
Dave's article is about the G-xxxSDX series - not the DXA. However, the
general thrust is correct - I have had both, and the cover removal is no
more difficult with the DXA's. The logic is fairly apparent and the box
comes apart without incident. However... before diving into a fairly
complex circuit, I would suggest you re-check your cabling
carefully. Assuming you didn't have something else happen, like some sort
of incident with a short to ground or lightning, that remains by far the
most likely source. If there is an open or intermittent connection on any
of the pot leads or one of the motor leads, the rotator will not turn. I
suppose that the way to be absolutely sure of the cabling is to measure
resistances (with the control box off and unplugged) at the points where
those 5 leads arrive at the control boards, or at least at the back of the
jack if that is accessible.
After this, if it is still not working, I would get on the phone to Yaesu
(use the number in their QST ads), and ask for Jerry Darby in amateur tech
support. Jerry is their most knowledgeable guy on rotators, was still
there the last time I called, and can probably suggest ways to isolate the
problem further. But in my 13 years with 4 of these rotators, the *only*
problems I have had have traced back to cabling.
Good luck!
73, Pete N4ZR
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