Cosmic Geoff

You can definitely take planetary images with this Maksutov + a dedicated planetary video camera. You do not need an equatorial mount for this and you could use the AZ-GTI mount, but a more rigid mount and tripod would make the excercise less trying. And you do not need a Barlow lens with this scope. Also a scope with this focal ratio is relatively forgiving of eyepieces, so you can select Plossl eyepieces for the lower powers if your budget is limited.

I have the Astro Essentials 50mm finder/guidescope, which comes with a proper focuser, takes 1.25" eyepieces (or T2 cameras), and comes with a two-ring mount on a dovetail bar that fits in a standard Synta finder shoe. (the mount rings alone might cost the asking price elsewhere.) I thought I could make it plate-solve with suitable attachments, but unfortunately it does not do this well under Bortle 6 when pointed at a random sample of sky. So what else is it good for? Guiding, I suppose. There does not seem to be enough focal depth to fit any sort of diagonal. It might do as a high-powered finder for planetary imaging (so long as the planet is not at too high an altitude).

The line of least resistance might to buy a used Windows laptop (pallet-loads of them refurbished from dealers on ebay) and use that for imaging rather than your expensive MacBook. Much more astro software is available for Windows.

You do need an IR cut filter. I tried my ASI224MC in daylight without one and the colours looked off. I ordered the ZWO IR cut filter with the camera, and also their IR-pass filter (since both filters were quite cheap).

When I was a lad I made an equatorial fork mount for a 8" F7 newtonian. I used sections of 3" diameter steel pipe screwed together with standard angle and T fittings., with roller bearings for the 'shaft'. It was not as rigid as I hoped, IIRC. Another suggestion is to look at the design of the Celestron CPC range of mounts and copy them. They use an alt-azimuth turntable which can be wedge mounted. You can find out from published materials how the axes are clutched and driven.

I use a ZWO IR cut filter, which cost about £20. It does its job, which is to eliminate the odd colour balance one would get if using an IR- sensitive camera without the filter.

You should be able to find a pair of holes that match with this finder shoe on your SCT. I can't say whether this will be the RDF mounting position. I actually used a different (cheaper) mounting shoe on my C8. You don't want to start drilling and tapping holes.

The chassis transformer you cite will do. But wouldn't it be less work to use one of the ready-made units? You do NOT have to match the wattage of the original TAL unit. Any 12v transformer capable of outputting 0.8A OR MORE will do just as well. It will output 0.8 A when connected to your motor, regardless of its capacity.

I have had a look at the PSUs. The panel mounted one is only 3VA so clearly unsuitable. You should be able to select a Pulsar unit that is: UK plug, 12v AC output, and delivers at least 8,5VA e.g. 8.5, 12, 15 or 20VA (and is in stock🙂). The more powerful ones seem to cost more. You also are expected to select the style of output plug (2.1 or 2.5 inner) I realise that neither plug may fit your motor, but...

That 'synchronous' makes me wonder if the synchronous motor is self-starting. If it isn't, maybe the power pack is OK and the motor has a kick-starter you have overlooked. (I have a synchronous mains clock that needs a smart tug on the setting knob to start it running.) Your PSU has a British label on it which suggests that, as you suggest, it is a replacement. You need a multi-test meter to check this gear out. For a competent person, making up a new PSU should not be hard. It just has to supply the right voltage and an adequate amount of current.

If that's the case, the supply presumably consists of a step-down transformer, and the problem can be solved by finding where there is a bad connection and fixing it, or replacing the faulty transformer with a new one that gives 12v output with a minimum of 8,4 watts.

Writing as a former electronics engineer: it definitely says "12v AC", but why? One could easily get 12v AC from a transformer, which is not a flat object, wheras a 240v to 12v DC power supply would look more like the object in the photo... Do the insides of the PSU, or the motor, offer any further clues?

If you happen to own a Startravel 102mm you can have a go at using it for imaging, and you can get some results. But if you want to do some serious deep-sky imaging you should buy something like an ED scope - the experts can advise which one. You will also need an expensive heavy-duty GoTo mount and (I suggest) the book "Making Every Photon Count" by Steve Richards, available from FLO.

There are various other choices and some people will recommend a Dobsonian mounted scope (because nearly all your money goes into the telescope rather than its mount). If you really want one of the two you cite, either would be fine. I have a Startravel 102mm f5, which is a bigger aperture and shorter focal ratio than the Evostar and while I can see the chromatic aberration it's not generally a critical problem. The Maksutov should be a fine scope (nobody ever complains about having a bad one) and is a size smaller than my Maksutov - an instrument I intend to keep. Either would be a handy grab'n go scope regardless of what you buy or upgrade to later.

I would suggest that you clean the outside of the corrector plate and see how that goes before you think of removing it. The corrector plate already has an obstructing mirror stuck in the middle of it, so a few specks of dust on the inner surface or on the main mirror are not going to make the performance any worse.

The picture shows a significant amount of dirt on the outside of the corrector plate. There is no evidence in the photo of any dirt inside.

How do you know that the mirrors (enclosed inside the scope body) are dirty? How would the dirt get in there? Dismantling these scopes is not a task for novices. If you are not confident about cleaning the outer surface of the corrector, it would be wise to let someone experienced do it.

That is a rather short focal ratio (f4) better suited to low power work eg viewing star clusters etc. It is likely to be quite demanding of eyepieces so I suggest you buy some decent ones (which can also be re-used with a future scope purchase).

What is your budget? The entry level outfits with GoTo will not offer a significantly bigger aperture than you already have. If you want a (visual) outfit with a non-wobble GoTo mount and a useful increase in aperture on your existing scope, brace yourself for some major expense. You could also look at Dobsonian mounts fitted with GoTo or digital setting circles- not any cheaper but might appeal to you.

A dew shield for a Maksutov or SCT should be regarded as a standard item, not an optional extra. Manufacturers clearly do not like to include them because it makes their product look big and naff. But all refractors have dew shields. 🙂 As others have said, it is easy to make a dew shield out of cardboard etc if you don't want to pay for a smarter looking one.

Mechanical and optical parts will last indefinitely if well cared for. Electronic parts may fail or become obsolete sooner than mechanics or optics. That includes older cameras - even if they work fine you may find that the utilities don't work on anything later than Winows XP. But I expect you will be looking mainly at 'nearly new' gear in which case, as suggested above, if it looks good and the seller seems reliable, then the gear is probably OK.

I suggest you read the other threads on this forum where a similar question was posed, and look at the 'Beginner scopes' offered by forum sponsor FLO.

A new SCT should not need collimating, but it is worth checking that the collimation is in fact good. A star should look like a point, or with a high power eyepiece like a tiny dot with circles around it (in good seeing). (This assumes you have a good quality eyepiece, not one of those starter kit things. Which is one reason I suggested buying a good eyepiece). When out of focus, a star should look like a circle with a hole in the middle. It should not look like a badminton shuttle. If you suspect this is the problem, I suggest you contact your dealer for advice, rather than trying to correct the problem yourself.

I thought I would describe my EEVA setup in hopes that it will help or inspire anybody who is interested in EEVA and wondering what to do. 102mm F5 'Startravel' achromatic refractor, ASI224MC USB3 planetary camera, EQ5 Synscan GoTo mount, Sharpcap 4 software, Dell Vostro laptop (7th edition, i5 processor, 8GB RAM, 256GB SSD, 42WH battery) None of this, except the laptop, was bought with EEVA in mind. The refractor - there are better refractors, but this model is cheap, quite well made, and the chromatic aberration etc is not too obvious in this role. The f-ratio matches the camera well, giving a ~0.5 deg. field. The camera - this is a sensitive camera with low noise. A bigger sensor would give a wider FOV but would cost more. The mount - as many of you will have learnt the hard way, Synscan mounts are not easy to use, but the plate-solve & resync available in Sharpcap 4 transforms this mount from an annoying and inaccurate ornament to a really useful tool. I previously used a SLT mount but while easier to use it was less stable. Sharpcap 4 - installed when I upgraded to this laptop. I originally got Sharpcap 3 for planetary imaging but it works just as well for EEVA, and the plate-solving available via this version is great. In a recent outing, this setup was highly productive and I was able to 'see' and record quite a large number of objects in 2 hours. Aimed at Mizar, it separated the 14" double onscreen with ease. In terms of objects made visible, this competes with much larger visual telescopes and has shown me objects I have never seen with anything else, including M1, M33 and Pluto.

Not unless you have incontovertible evidence that it's faulty. Anyway those 10mm starter eyepieces are all poor. Just buy a better one.