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Maybe its old age, but I cant resolve this issue. When I set up (Obsession f5/20) I basically have the scope pointing North and at 90'. Power on the Cat and Argo and it goes through initialing and gives beep synch tone and do a fix alt ref. Now if I go to Mode Encoder I see my AZ is almost always about 90' as if pointing east? Why is it nolonger reporting 0 when pointing north? This deviation makes alignment and/manual targeting a bit more challenging. Did I miss somethin? Suggestions??
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Thanks
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Hey Sam... long long time no hear. I'm trying to remember - was it not you that (Jean and) I met way back in like 2001 or so - you had an observing site near I think it was Huachuca City?? Anyway... so first what I'd do is to go to MODE ENCODER and confirm the AZ axis is reading as you move the scope.? Second are you sure you are hitting the FIX ALT REF twice ... once to get in to the mode and once to do the action?? Last check the MOUNT TYPE. Make sure it is set as I believe ALT AZ MOUNT.? The sequence generally is - or at least what I do - point the scope roughly north and to the ALT REF position (most have this as 90)... turn on the system - hit enter twice. Now you can go to MODE ENCODER and the AZ should read 0 (the ALT the ALT REF value).? g. ------ Original Message ------
From "Sam Selig via groups.io" <bigdob1400@...>
Date 3/5/2025 9:34:46 AM
Subject [ServoCAT] Argo-Navis & ServoCat off in AZ
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Hi Sam,
Your scope is fitted with incremental encoders and they have no inherent zero reference point. ?
The zero reference point for the altitude encoder when the unit is first powered on is determined by whatever angle you have in the FIX ALT REF menu (typical) 90 and whatever angle in altitude the OTA happens to be.
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When the FIX ALT REF step is performed, the altitude zero reference point is re-established by it.
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If you are using AUTO ADJUST ON (and you should) when you perform the two-star alignment or any subsequent alignment, the altitude zero reference point can be automatically adjusted. Usually this is a "tweak" from the reference point you initially established when you did the FIX ALT REF.
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So that's the altitude encoder but you are asking about the azimuth encoder. How is its zero reference point established, you may ask?
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The rule for it is simple. The zero reference point is the arbitrary orientation the scope happens to be in azimuth when you power it on.
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Whereas the zero reference point for the altitude encoder is important, for the azimuth encoder it matters not.
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So for example if the scope happened to be oriented to the north when you powered it on, the zero reference point would be 0.
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MODE ENCODER provides a readout of the encoders within "encoder space".
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MODE AZ ALT provides a readout of which way the scope is pointing in a topographic sense, like that from a compass and sextaant, but only after you have performed a star alignment and if your location is established in SETUP LOCATION and time in SETUP TIME. It works by starting with the RA/Dec position the scope is pointing at and then performing the classical transformation to convert it to a topocentric geographic coordinate pair.
I hope this in-depth answer helps clarify things for you. ?
--
Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place
Mount Kuring-Gai NSW 2080
Australia
Phone +61-2-9457-9049
sales@...
https://www.wildcard-innovations.com.au |
Sam Selig