EQ6 - Synscan HOME Positions

[daz]

Having had a chance to play with Synscan over the weekend, I did some research on where Synscan thought HOME was - as everything is calculated relative to this.

There were many different explanations (as you might expect) of doing the same procedure, so here is my summary of what I did. It may be of use, it may be incorrect, in which case feel free to comment.

If its of use, I'll put in the tips & tricks section:

1) Align polar reticule

1a) Adjust the ALT until you can see something on which to align the reticle - church spire, pylon, tall chimney, etc.

1b) Using a spirit level, check that the mount is perfectly level horizontally

1c) Carefully centre the cross on your chosen target, using the AZ and ALT bolts

1d) Now rotate the mount in RA for 180 degrees, and again, check its level

1e) Look through the polar scope. Your target should remain in the same position as 1c. If not, you need to adjust your reticule, using the three set screws

1f) Only move the cross 1/2 of the distance towards your target!!!

1g) Turn the mount back 180 degrees to the beginning

1h) GOTO 1c until there is no difference in the target when you rotate the mount.

Your reticule is now aligned correctly.

Now, adjust the ALT again until the mount head is perfectly level horizontally - i.e. the front panel of the mount points up!

You now need to mark the mount in some way so you know where this position is. This is what I did:

1) Move the RA setting circle so that 0 is exactly on the pointer

2) Make a small mark on the mount head above the 0 number - remember you will need to be able to see this in the dark, so tip-ex or something similar might be useful

Repeat for DEC. I actually locked my DEC circles at 90, as using the GOTO, I don't need to use it. Again, remember that if you mark the mount, you'll need to see this mark in the dark.

Accuracy and repeatability are the key things here.

To test your marks, and the repeatability of aligning, reset the ALT back to your normal reading and switch on the mount. Drive the mount in both axes and then send it back home. It should come to rest with your marks perfectly aligned.

JOB DONE!

So, thats how I did it - again, I'd be interested in other peoples comments/experiences

P.S. In the manual it says that you can connect RS232 via USB-SERIAL connection. Its a lie!!! The Yahoo group is littered with posts from people who can't. Luckily I had a old laptop with a serial port on it. I shall be obtaining a PCMCIA card with a serial port on it to test if I can do it this way - again, others on Yahoo have reported success, so I will confirm.

[Ant]

Having had a chance to play with Synscan over the weekend, I did some research on where Synscan thought HOME was - as everything is calculated relative to this.

There were many different explanations (as you might expect) of doing the same procedure, so here is my summary of what I did. It may be of use, it may be incorrect, in which case feel free to comment.

If its of use, I'll put in the tips & tricks section:

1) Align polar reticule

1a) Adjust the ALT until you can see something on which to align the reticle - church spire, pylon, tall chimney, etc.

1b) Using a spirit level, check that the mount is perfectly level horizontally

1c) Carefully centre the cross on your chosen target, using the AZ and ALT bolts

1d) Now rotate the mount in RA for 180 degrees, and again, check its level

1e) Look through the polar scope. Your target should remain in the same position as 1c. If not, you need to adjust your reticule, using the three set screws

1f) Only move the cross 1/2 of the distance towards your target!!!

1g) Turn the mount back 180 degrees to the beginning

1h) GOTO 1c until there is no difference in the target when you rotate the mount.

Your reticule is now aligned correctly.

Personally I think that everyone should do this if they have a polar scope. I didn't realise that it would need doing. It was only when I started to get bad tracking after accurate polar aligning (using the polar scope), and good tracking after just plonking the scope down in a hurry.

Daz mentions 0 degrees and 180 degrees, I did the same thing at 90 and 270 just to make sure.

It's a 10 minute job, very easy to do and the steps above are spot on.

Now, adjust the ALT again until the mount head is perfectly level horizontally - i.e. the front panel of the mount points up!

You now need to mark the mount in some way so you know where this position is. This is what I did:

1) Move the RA setting circle so that 0 is exactly on the pointer

2) Make a small mark on the mount head above the 0 number - remember you will need to be able to see this in the dark, so tip-ex or something similar might be useful

Repeat for DEC. I actually locked my DEC circles at 90, as using the GOTO, I don't need to use it. Again, remember that if you mark the mount, you'll need to see this mark in the dark.

Accuracy and repeatability are the key things here.

To test your marks, and the repeatability of aligning, reset the ALT back to your normal reading and switch on the mount. Drive the mount in both axes and then send it back home. It should come to rest with your marks perfectly aligned.

JOB DONE!

So, thats how I did it - again, I'd be interested in other peoples comments/experiences

Sorry mate, I don't understand what the purpose of this is. I'm not saying that you do not need to do it - just don't understand why!

I was always under the impression that a mount didn't have to be level providing that the polar scope (if it's aligned to the mount as above) is aligned to the north pole. Surely the act of doing a two star alignment tell the scope where it is?

An interesting read though,

cheers

Ant

[jarbi]

P.S. In the manual it says that you can connect RS232 via USB-SERIAL connection. Its a lie!!! The Yahoo group is littered with posts from people who can't. Luckily I had a old laptop with a serial port on it. I shall be obtaining a PCMCIA card with a serial port on it to test if I can do it this way - again, others on Yahoo have reported success, so I will confirm.

Daz,

I am definitely one of the lucky one's, because I have RS232 connection with my EQ6 from Starry Night Pro via the Ascom driver ( I have choosen Celestron / Nextstar 5 as scope, and I have the new upgradeable hand controller ). I am using the USB to serial adapter & 5m link cable from Astronomiser, connected to the RS232 port of the hand controller.

At the beginning I couldn't connect neither, because the Ascom driver cannot use COM port numbers above 16. To resolve this, I needed to rearrange the port assignments in XP to have the adapter's port number under 17 - and there it goes ! I hope this may help you out.

cheers,

Janos

[Whippy]

Nice one Daz, should be a sticky in T&T. I'm assuming that I'm going to have to align/calibrate my polarscope when I get one for my CG5, I couldn't imagine something simple in astronomy as just screwing the thing in and off you go :shock:.

[russ]

Daz,

I am definitely one of the lucky one's, because I have RS232 connection with my EQ6 from Starry Night Pro via the Ascom driver ( I have choosen Celestron / Nextstar 5 as scope, and I have the new upgradeable hand controller ). I am using the USB to serial adapter & 5m link cable from Astronomiser, connected to the RS232 port of the hand controller.

At the beginning I couldn't connect neither, because the Ascom driver cannot use COM port numbers above 16. To resolve this, I needed to rearrange the port assignments in XP to have the adapter's port number under 17 - and there it goes Smile ! I hope this may help you out.

cheers,

Janos

Had to do the same thing to get the EQ5 Synscan working with SN5.

Russ

[daz]

Sorry - I appear to have missed out some vital info!!

The polar reticule alignment is not necessary do set the home position, but as the mount head is going to flat, you may as well do the two jobs at the same time.

Sorry for any confusion there!

The purpose of knowing where HOME is is for the Synscan. When you initialise the mount, I *think* it assumes it is at HOME position, and therfore everything is calculated from that. Ergo, if your mount is not at HOME, then the mount will not point at the correct star. I can now repeatedly position the mount at HOME and know that the mount will be starting at the correct spot. Incidentally, in V3.12, you can now edit your HOME position to where you like.

As for the USB bit, again, I missed out some vital info (I really MUST start rereading my posts). This was updating the firmware via RS232 and a USB-SERIAL interface. The USB-SERIAL is on Com4, but the firmware loader flatly refused to sync, even with the speed set to LO. This is a direct interface and so does not use the Ascom drivers.

Sorry for all the confusion. I'm off for a lie down!!!

[Whippy]

On my CG5, there's these little labels that you have to align before you start the erm, alignment process (essentially pointing straight at the pole), these I assume are the equivilent to the EQ6's HOME position. Odd that there's none on the bigger, more expensive mounts...

[MikeP]

Possibly not relevant to this discussion, but I'll pass it on anyway ..... always PARK your scope.

I tried several times to use the GOTO with no success. A few nights ago I tried again and was about give up when I thought I'd see what happened when I parked it. My assumption was that it would point roughly towards Polaris (my polar alignment was done with a compass since I find the polar scope an instrument of torture for my back) - it pointed absolutely nowhere near. I switched off the mount, manually rotated the scope to a position that looked right to me and then switched on again. For simplicity, I did a one star alignment on Vega and then tried to GOTO the Ring Nebula. Success - the first DSO I have ever seen. OK, it wasn't slap bang in the centre of the eyepiece, but good enough for me.

Don't ask me why it worked, I could rationalise a reason, but I didn't care - I was as happy as a pig in the proverbial. I found Albireo and the Dumbell Nebula and found my way back to the Ring Nebula. I can't wait to try again in a more open bit of the garden, weather permitting.

Rest assured, I PARKED the scope before switching off.

Mike

[Kaptain Klevtsov]

To add a little to the "park" position, the main reason for having this is to ensure that the mount starts in the right place to use any PEC training that you have done. It puts the 'scope to a known start position WRT the rotational positions of the cogs and stuff (technical term).

Captain Chaos

[daz]

I love your technical terms CC - I have to run off and look them up

[daz]

An update .......

In my first post, you will recall that I marked the mount just above the RA and DEC pointers - this now appears to be a bad choice of position when using the 10" Newt as the tube gets in the way a fair bit! So, task this weekend will be to make new marks off to the sides where its easier to see them!!

Second, I bought a cheap PCMCIA card with a serial port which connects to the handset for firmware updates. Works perfectly. Firmware takes about a minute to flash through at full speed

The USB-SERIAL interface to RS232 for remote control works great as a Celestron (forget exactly which one)