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Old 31-12-2014, 01:46 PM
inertia8 (Australia)
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Apologies for those in NE Suburbs of Melb

Hi All,

I have just taken delivery of a secondhand SW Heritage 130p, which I believe will likely lead to a couple of weeks cloud cover in the North East suburbs of Melbourne, so apologies are in order.

That said, it's an impressive little dobsonian and I do hope that clear skies prevail!

Collimation from eyeballing seems ok, I have put my Orion cheshire into the foscuser but there is a large amount of slop between the edges of the focuser and the orion sight tube, so that when doing up the grub screws it moves the crosshairs about... not sure how i'm going to get past that but I suspect a couple of turns of electrical tape around the sight tube at the correct depth??

It was purportedly used twice. The condition seems fairly good, there's marking on the dovetail bar from it sliding against the grub screw, the primary seems crystal clear with a little dust hear and there, there is unfortunately a couple of little fingerprint smudges on the secondary mirror, which are thankfully to the outside edges of it so they can stay there for now, though they annoy me so I will probably prepare to clean it prior to collimation.

Apart from the included eyepieces, which are labelled super 25mm and super 10mm... I have a 15mm Bintel SuperView and a TMB Planetary II 6mm (which I believe might not be too good in this fast scope).

First target would be the moon, however I don't yet have a filter for it, so probably Orion.

Any suggestions?

I shall have to take it along to an ASV meet to get help on the colimation process, however I've looked at astro-baby's guide and whilst it seems straight forward enough, though it hasn't quite "clicked" yet.
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Old 31-12-2014, 02:55 PM
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barx1963 (Malcolm)
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Hi Inertia

Well done on getting a scope. My usual advice to beginners with new scopes is not to get hung up on collimation. I have seen people spending hours trying to get the collimation "just right" when they could have spent that time actually using the scope. The sight tube can be thought of as duplicating the eyepiece, so if it is slightly off centre when you tighten the grub screw, then the eyepiece will do the same, assuming that the sight tube and eyepiece barrel are the same diameter.
Apart from that, following the Astro Baby sheet will get you on the money!
With cleaning the secondary, just be careful, it is very easy to damage optical coatings if too aggressive with cleaning. Best strategy with mirrors is not to look too hard at them, that way you won't see the dirt!!

You do not need a moon filter to look at the moon, it will be bright but a small scope like that will not be an issue (try it in a 20" some time!!). It is often nice to observe the moon at the moment at dusk, easy to see and check out but doesn't ruin your dark adaption.

If you are looking out for a dark site, we are having a camp at Snake Valley in March (weekend of March 20-22) so keep an eye out for details.

Cheers

Malcolm

Last edited by barx1963; 31-12-2014 at 04:40 PM.
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Old 31-12-2014, 05:35 PM
inertia8 (Australia)
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Thanks Malcolm.

Indeed I'm leaving collimation for now, it focused well onto a distant dead tree. Though when I centered the top of one of the branches and attempted to align the red dot finder i've run out of adjustment and cannot get it to align with the main scope.

One other thing that I've found a bit unsettling when using is the ability to see past the edges of the secondary mirror when using the included 25mm eyepiece.
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Old 31-12-2014, 07:33 PM
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creeksky (Pete)
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Congrats Inertia on the new scope,hope the skies keep clear for you and you see great vistas!
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Old 31-12-2014, 08:15 PM
inertia8 (Australia)
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Thanks Pete. Good luck with your search!

Well the terrestrial views were crisp enough to see termite/insect etchings on a tree that's a good couple of hundred meters away. Happy enough with that.

I shall report back. Partly cloudy here but we'll see
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Old 01-01-2015, 01:23 AM
inertia8 (Australia)
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Not too bad, bit cloudy but stayed clear to the north east allowing some viewing of orion, comet lovejoy and later on jupiter, with some banding occasionally visible and moons? Seemed like moons. I also had a good look at the moon but it was constantly behind a cloud.

One question. In the daylight viewing the tree and when viewing the moon, when using my 15mm super view or the 6mm tmb planetary I could see 3 black dots that would rotate around when I turned the helical focuser. I thought it was a defect in the 15mm but it appears in the 6mm as well. Is this the secondary and it's bracket?
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Old 01-01-2015, 09:10 AM
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http://telescopereviewsuk.wordpress....ian-telescope/

QUOTE=inertia8;1144231]Not too bad, bit cloudy but stayed clear to the north east allowing some viewing of orion, comet lovejoy and later on jupiter, with some banding occasionally visible and moons? Seemed like moons. I also had a good look at the moon but it was constantly behind a cloud.

One question. In the daylight viewing the tree and when viewing the moon, when using my 15mm super view or the 6mm tmb planetary I could see 3 black dots that would rotate around when I turned the helical focuser. I thought it was a defect in the 15mm but it appears in the 6mm as well. Is this the secondary and it's bracket?[/QUOTE]

Thats great!
I have found some great reviews of this little scope, some say its views of DSOs are better than a 12inch Dob! (See above link)
Was wondering if I could "hack" the nat geo one by cutting off the top or moving the spider to look like the your scope and if that would make it better,?but maybe best to buy one like yours.
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Old 01-01-2015, 11:22 AM
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barx1963 (Malcolm)
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Just read that review and it did not say that its views of DSOs are better than a 12" dob. What it said was
"At this point I have to say that some telescopes magnify too much, not this one, this has to be the best view I have ever had of these two galaxies, believe it or not, my 12 Dobsonian does not do them justice!"

This is an important point as for some objects, in this case the M81, M82 pairing but others such as the Grus Quartet, the Leo Triplet, the M31, M32, M110 trio (which the review mentions later on) a low power, widefield scope is ideal. However when it comes to detecting faint stuff, and it should be noted that the example in the review (apart from one, the Veil nebula) are bright DSOs, nothing beats aperture. It is simple physics, collect more light, see more stuff.

The important lesson is that no telescope does everything well, while a great starter scope, it will have strengths and limitations that need to be understood to get the best out of it.

Cheers

Malcolm
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Old 01-01-2015, 12:13 PM
inertia8 (Australia)
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One such limitation seems to be needing a solid table! And mine did not come with the piece of plastic to go behind the mirror and as such I'll be making a shroud for it.

I was viewing from my deck, which is a meter an a half off the ground and using a small iron work garden table and it was rather frustrating to have every movement translated into a wobble at the eyepiece. I'll be trying to sort something out, maybe a home-made tripod base at a comfortable viewing height.

Pete,

I don't believe you can hack the nat geo scope in that way and the end result would not be worth it. Keep an eye out on ebay or the classifieds section here, or wait for OzScopes or Australian Geographic to have a sale etc if you plan to get one of these.

I still plan on getting a Skywatcher Black Diamond 10" Flex Tube Dob in the future. The purchase of this little dob was to give me something portable that I can take camping etc and also because it can be quickly plonked out on a table in the yard and ready to go without much fuss.

If you are looking at a single scope then I believe a 6"-10" dob is very good value, see if you can get to either Andrews or Bintel to see them in person and decide on what size you can manage easily. I almost bought a 12" Bintel Dob on here because the price was amazing but missed out to another member, a week later I was staring at the same model dob in the Bintel store and was glad that I missed out, it would have been a chore to get that thing out for me. Good Luck.
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Old 01-01-2015, 02:09 PM
inertia8 (Australia)
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A couple of questions.

I mentioned in one of my posts the presence of black dots or something similar, which rotate when using the helical focuser when I use it with certain eyepieces.

So, does anyone happen to know if this is perhaps just the shadow of the secondary mirror and its holder and is mainly noticed when focusing on the moon and other broad/bright objects and due to the nature of the helical focuser?
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Old 01-01-2015, 04:42 PM
inertia8 (Australia)
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Fyi, as per other forums, I have fixed the rdf alignment issue with a two staples broken off to keep them stuck together. I bent the arms inwards to provide tension and then inserted the staples into the groove in the bottom part of the dovetail mount on the scope. This prevents the fine edge of the dovetail clamp from reaching the bottom of the groove and thus forces the finder to point downwards. Two staples were almost too much and it also means the finder can be rocked a little causing it go out of alignment. So, not a perfect fix but quick and workable.
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Old 01-01-2015, 08:42 PM
inertia8 (Australia)
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The issues with my 6mm TMB planetary and 15mm Bintel Superview showing black dots appear to be manufacturing defects in both

If I hold up the eyepieces themselves to clear blue sky and rotate them, the same black bubble-like dots and marks are abundantly clear.

Should I be returning these eyepieces for replacements or is this normal for lower-end eyepieces?
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Old 02-01-2015, 11:10 PM
inertia8 (Australia)
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Talked with suppliers and I am returning the eyepieces.
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Old 03-01-2015, 02:26 PM
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Returned the tmb 6mm for an explore scientific 82degree 6.7mm. Hoping this will be a good piece to use with the heritage and my future 10" dob.
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Old 03-01-2015, 04:58 PM
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Quote:
Originally Posted by inertia8 View Post
Returned the tmb 6mm for an explore scientific 82degree 6.7mm. Hoping this will be a good piece to use with the heritage and my future 10" dob.
That good,Hope you can get a clear night to go out and try tonight,let me know if you see any colourful objects?
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