Problem with CG5 GOTO

[robindurant]

Hi

First may I say that I am new to the CG5 Goto but am conversant with Celestron Goto. I have used this Mount 3 times and the goto has been accurate but last night it missed Capella, the first star by approx. 20 degree alt downwards. I tried 4 or 5 times again with the same result. I use GPS so the settings should be OK but I switched it off and entered the up dated time (daylight setting) date and coo-rds. Same result. So I turned on the GPS, tried again and again it missed by the same margin. I therefore loosened the clamps and manually turned the scope to Capella, re tightened and carried on successfully, spot on. It would seem that the line up arrows on the Mount are incorrectly positioned but it had been OK on the previous nights. It also seems that it is looking for Capella where it would be approx, 1 hours time. As I say not being used to equatorial mounts, I ask myself if this is the normal way to operate them. Maybe someone can advise me.

Robin

[Naz]

Not familiar with goto's Robin, but do you have to put the time in as daylight saving? surely it should be still GMT / UHT. The universe doesn't keep daylight saving time, so everything is still there in the same place, time wise.

As you say the scope points to where Capella would be in an hours time.

Maybe some one conversant with goto's will be along in a moment.

naz

[James]

The GPS satellites operate on the standard time zones, i.e. any GPS will always return the local GMT time for us in the UK even during the summer months. I haven't used the GPS unit on my CG5-GT - does the process require you to enter DST/BST whilst aligning? If so you will need to let the unit give you the time and then choose DST/BST to get the corrected time. If the handset doesn't ask for DST/BST then I'd expect it to be giving you the 'wrong' time i.e. would be an hour out. As Naz says the universe doesn't suddenly shift everything so the time given wouldn't actually be wrong, it would just look wrong!

The other thing to consider is that the mount remembers its Home position (usually with the index marks aligned). If you manually release the clutches and move the scope then it will get confused next time. You will need to enter everything correctly then slew the scope to the alignment stars using the handset. Once done correctly the next time you align it should be a much quicker experience!

Hope this helps.

James

[robindurant]

Hi James

The handset does not ask whether to set daylight or not settings so I assume that the GPS knows this factor. I tried re adjusting from the bad position to the first chosen star, Capella with the handset, so that it did not confuse itself with its home settings but this did not work as the next star it chose (Polux) was still way out, I then re adjusted Polux by the handset and it chose Regulus for a calib start and this was also way out. It was only when I un clutched and move the OTA manually to Capella did it prove accurate on the other stars, queer what!