Graham,
Recently, I had an opportunity to buy a Celestron NexGuide autoguider in the US which appears almost identical to the Synguider (in fact it looks identical even the handcontroller!! only rebadged)
I have tried it out on a friends G11 (as I am upgrading to a G11) and found this little blighter very handy.
Here are my dot points :
1. If bought from the US, it worked out to be about AU$285. So budget wise good.
2. No laptop needed. It is selfcontained
3. The Celestron one auto calibrates itself (ie it works out what is left, right, up down to determine the correct commands once a star has been locked)
4. We ran this unit for 4hours and the locked star stayed on a dX and dY of 0 each with a maximum variance of +-2 pixels (PEC off)
5. We concluded it did the job quite nicely.
6. Obtaining a guide star is however (imo anyway) much more difficult than watching a separate camera feed back to PC (I am used to Guidedog with my old LXD55 and Neximage CCD camera). The reason is that you only have about the size of your thumb of LCD area to watch on these guiders. The refresh is fairly slow and trying to focus is difficult. The "star" is simply shown as a black LCD dot on an orange LCD background. Very basic.
7. As a result of 6, you really need to centre a reasonably bright star (we only tried it on Antares and Mimosa) before putting in the guider.
8. As for power, Celestron runs from 6V to 14V from memory. We cut the battery lead and wired it to a plug/socket to run from 12VDC. The manual did state that running from a lower voltage is better for long term reliability. I put in a 12 Ohm 5W resistor in series to drop the voltage down to below 9V. It's not critical though.
9. I was quite happy with its performance but it is awkward in setting up and getting that guide star. Well worth a look if you don't intend to have a laptop in the field.
I hope this helps you Graham.
Cheers,
Darrin...
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