CEM40 EC Review Part 3

[STEVE333]

Life has been busy for some time here. The other night I finally had a chance to run the PHD2 Guiding Assistant to measure the performance of the CEM40 EC mount.

The process was as follows. First I did a Polar alignment using the CEM40 iPolar capability. Next I initiated the PHD2 alignment process and, after guiding had started, I initiated the Guiding Assistant with the Measure Declination Backlash box checked. I pressed Stop after this ran for a little over 2 minutes. This immediately started the Declination Backlash test which ran for a few minutes and then stopped on its own.

The result was that PHD2 determined that NO Backlash Compensation was required! A very satisfying result indeed because eliminating backlash problems was why I purchased the mount in the first place.

Hope this is useful for you.

Steve King

[STEVE333]

Just a further clarification of the Dec Backlash test results.

PHD2 measures Dec Backlash in units of TIME (seconds). I believe this is the amount of time it takes the mount to clear the backlash, so, smaller backlash "time" is better. My ZEQ25 mount had a Dec Backlash of about 7 or 8 seconds (possibly my fault as a result of my trying to "tune" the mount multiple times). The CEM40 EC mount has a measured Dec Backlash of less than 100 msec! (less than 0.1 sec!) according to the PHD2 measurement. Because the Dec Backlash is so low PHD2 doesn't even bother correcting for it!

The guiding I've achieved so far definitely corroborates that Dec Backlash is not an issue for this CEM40 EC mount.

I found it interesting that there is not even a provision in the CEM40 EC mount to enter any Dec Backlash corrections!

Again I hope this is helpful.

Steve