What autoguider would you recommend to guide a CG5?

[g__day]

It's interesting that Celestron sell their CG5 goto mount advertising it has auto-guiding capabilities (a 6 pin port) built into the mount, but that's all they say. They don't say what auto guiders it supports, they don't say which it won't, they don't even sell any as accessories.

So I'd thought I'd ask folk here what might be recommended as an entry level auto-guider that will suit this mount and will this choice grow with me, or am I likely if I progress to sell this and hit an upgrade point (and what triggers this if it is needed)?

Many thanks for any suggestions you can give me folks!

[EzyStyles]

hi g__day, you might want to read this:

http://autostarsuite.net/forums/thread/6610.aspx

The CG5 is compatible with DSI/LPi's which you can use as autoguiders. Im using a DSI as one for the EQ6.

cheers.

[Merlin66]

The six pin connector sounds like the industry standard, so should accommodate any guider. I use an ST4 on my system.

[g__day]

Thanks guys, I'd actually already read those post BTW and am deciding if I should build my own parallel port connector. At the moment I'm unsure if you need to send both of power and ground to the mount, or enither if its a PC directing it. Also I need to understand if these pins can be directly connected or if any signal or curren t / voltage conversion is needed. Has anyone bought and used one of shoestring's adapters - especially the parallel port one?

I'm a bit dissappointed Celestron don't advertise what autoguider brands will work with there mount. Given my PC is a fair way away from the scope I'd prefer to avoid USB cabling and go for a dedicated device, but I don't what to go to the high end S-BIG gear yet. Aren't there any low end choices that work pretty well?

[JohnG]

If Celestron state that the CG5 is ST-4 combatable then it should comply with the standard SBig used with original ST-4 pinout.

As far as autoguiders are concerned, I would ask myself what my photographic ambitions are, meaning, do I start off with an autoguiding system that MIGHT be OK or do I go with a dedicated autoguiding system. As one would appreciate, there is a significant cost difference.

As far as entry level systems go, possibly using a Toucam, LPI, DSI or NexStar coupled with free guiding software like GuideDog or Guidemaster or, for a cost K3CCDTOOLS.

For a more advanced system, ST-4 (if you can get one), STV (I think they are no longer available) or one of the cheaper SBig cameras, the major problem is the cost here.

Each has it's advantages and disadvantages and if you are limited to a budget, the Toucam, LPI/DSI or nexStar is the way to go. I did significant tests using an LPI -v- ST-4 and, obviously the ST-4 came out on top BUT that was before Guidemaster had the LPI long exposure support, the downside of using the LPI is that to get long exposure mode you have to install .Net 2 and DirestX 9.0 and above. The biggest problem I found was that you needed to get a fairly bright guidestar for things to work properly.

On top of this, one has to consider how it is to be all connected.

Hope this helps a little.

Cheers

JohnG :)

[EzyStyles]

just a point of note. a ST4 autoguider very expensive. I think over 1k. i don't think it is more of an entry level autoguider which you want. exactly what JohnG have said. A DSI is quite sensitive when it comes to guiding a star. Tested it out last night guiding a very dim star no problems at all to even 1 pixel.

[JohnG]

In answer to the other part of your question, I have and still use a Shoestring Astronomy parallel adapter. I found that it worked quite well, no major drama's, you may have to muck around in the BIOS to get your settings right but that was no big deal. Couple that adapter with a flat long autoguider cable and it worked just fine with GuideDog and Guidemaster.

This setup is for my GM-8 mount and used with my Laptop gives me an autoguide setup in the field using the Meade LPI as the autoguider.

I use the ST-4 on my permanent setup with the G-11 and Gemini.

JohnG

[g__day]

John

I'm thinking thats my next step. Can you please tell me:

1. did you purchase the parallel adapter locally from someone or import it (and what was the wait time)?

2. does it require a 6 pin or 4 pin cable (I can't figure if power and ground are actually used, or just ground, neither or both, I'd guess neither given the documentation states "It uses the D4, D5, D6, and D7 lines of the parallel port"). Mind you the doco says purchase a RJ12 (6 wire cable) if you make your own - so I guess its allowing for devices that want power and ground - I just can't figure what pin out of the parallel port is power!

3. In the BIOS is your parallel port set to ECP, EPP or a lower setting to get this to work?

4. Did you get the cable from overseas or just make it yourself?

5. Does the mount still slew at normal rates or is slewing through the auto guider port actually slower?

6. Can you tell is the connector just a simple wired parallel port connector to RJ12 (6 pin) connector + pass through to another parrallel port, or does it have other electronics to shape / isolate the current?

Basically I'm wondering if this is basically a Jaycar $6.40 part or if its got resistors or any fancy circuitry to make it work. If its a simple port I could easily wire my own, if its involved electronics, I could part with USD $32 + shipping USD $7+

Many thanks,

Matt

[JohnG]

Hi Matt

I will try and answer your questions as best I can, I am not a tech by any means, some of my answers could well be better explained by other people. LOL

1. I imported my bits and pieces direct from Shoestring Astronomy, I emailed them first and they replied almost immediately with the cost to send to AU. Time from submitting my order to receiving was just over a week. Shoestring advise you by email when the article is posted.

2. It requires a 6 pin cable with RJ12 connectors. Go to the site here:
http://www.store.shoestringastronomy.com/products_gp.htm

scroll down to the GPINT-PT picture, there is a downloadable manual that has a pinout diagram.

3. ECP (You MAY have to try the others) The free downloadable port checker, I found, used a different port setting, strange.

4. I purchased the following: GPINT-PT, Cable GPFC-14 and a Guide Port Splitter, I still need the use of my hand controller.

5. I can't answer for your mount but my GM-8 without Gemini or DSC's I move by hand and final slew using the hand controller, the autoguider plugs into the splitter and I simply reset my guiding speed to .5x. I had trouble using this system with my G-11 mount with Gemini, I kept getting an autoguider error, so it is not used on the G-11, that is where the ST-4 comes into it's own.

6. As far as I know, it is just a simple 6 pin, RJ12 connector. As far as I am aware, the GPINT-PT is an isolator, you might want to look at the link above and the manual.

Your last remark, I am unable to help you there, I am not electronically savy. I found it was easy to just get the parts as a complete package from Shoestring, everything has worked just fine since I got them.

Hope this helps a little

Cheers

JohnG :)

[g__day]

John huge help thank you! I think will buy vs build this, as the isolaters could be resistors, integrated circuits or something fancier. I'll custom make the cable though!

Many thanks,

Matthew

[Harpspitfire]

way off topic again- but i have the ASGT-CG5, im also computer stupid- i couldnt get guidedog to work with my webcam- again this is user fault- i see guidemaster and startrack seems user friendly- though im stii in the 'how does work' stage- i think these 2 programs will fit my 'guiding for dummies' criteria

[g__day]

That is a thing that I too as a new user observe, there appear to be:

1. fewer industry standards than I expected (Meade and Celestron do their own things) rather than comply to standrds they foist on the rest (particularly for software interfacing to their mounts

2. Celestron don't go out of their way to document how their mounts specifically operate nor describe any software interfaces nor tell what open standards software can interact with their hardware

3. Manuals for most equipment are technically dry and not well written to do more than boot your equipment and show you the basics. There is poor troubleshooting or expectation management. There is almost no planned learning ladder and next steps to wlak you through.

The journey towards knowledge seems alot less well planned in this regards than it ever needed to be!

[JohnH]

John, did you actually get the LPI long exposure to work? I abandoned it in the end and went for an Orion Starshoot, the LPI seems to only work on very bright stars, long exposure allows you to see fainter stars yes but the noise soon drowns out any advantage - and you need to stack and dark fram to counter that (which the s'ware does not do and would take too long in any case) not really useable IMHO.

[JohnG]

Sorry John for the late reply, have been away. All my tests were done on the short exposure mode, Guidemaster did not, at that stage, have the long exposure mode operational. Like you, I found the LPI needed a bright star. I am led to believe that the latest version of Guidemaster has fixed a number of bugs but I am unable to confirm that. I have not tested the latest version at this stage.

I have kept the LPI to use on my non-Gemini, non-DSC, GM-8 for field use, I will get round to testing in due course.

Cheers

JohnG