I found a similar problem in trying to cal a Yaesu G-1000 on an RT21. A
large number of tries using the manual procedure still had significant
error in the readout vs actual azimuth for significant portions of the
compass.
Removing this rotator and bench testing revealed that the 500 ohm pot
that provides the G-1000 position voltage that the RT21 digitizes was
not correctly installed or was damaged. The G-1000 has a hard stop at
CCW 180* (if north centered). The pot reached its zero limit value well
before the rotator stopped turning, determined by using the Yaesu
controller (could also be tested with an ohmmeter and DC supply).
So the RT21 interpolation of CCW 180* and CW 180* digitized voltages
would not work. The Yaesu "overtravel" feature can further confuse what
is wrong.
A rotator with a reed switch for turns counting would not have these issues.
My G-1000 is sitting for a bench disassembly. The Yaesu pot is not just
any 500 ohm pot as it requires rotation that exceeds the usual
mechanical limits of standard pots. I don't remember that value but
know it exceeds 300* but it is not a continuous rotation pot.
Of course if antenna or mast are slipping that problem needs fixed first.
Grant KZ1W
On 5/23/2022 06:09, john@kk9a.com wrote:
I'm sure that W2FU could give much better advice but I believe offset is
where your rotator stops, most of us use south. Hy-Gain rotators have
switched stops in them so if the antenna is not aimed properly it will no
longer be stopping on south plus if something is slipping it will continue
to do so until that issue is resolved. For my rotators with pulse counters
and no stops I simply turn the antenna true north and set the control to 0.
For my rotators with potentiometers and no stops, I do a calibration however
this will only work if the pot is close to midrange when the antenna is
north.
John KK9A
Kim Elmore N5OP wrote:
I've determined that my antennas point a fair bit east of the direction
indicated on my RT-21. Rather than rent a lift and readjust them, can I set
a general offset bias within the RT-21? I'm confused by what the "offset"
does based on the manual. My rotator is a T2X, but I can't imagine that
makes much difference.
Is there a setting that does what I want?
Kim N5OP
"People that make music together cannot be enemies, at least as long as the
music lasts." -- Paul Hindemith
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