GS or Saxon 10' DOB

Eardrum73 · #1 15-09-2005, 11:58 AM

HI there,

I want to ask Dob users out there about your dobs. I am considering what type of scope to get and the 10' or 12' dob has been included as an option.

The GS or Bintel Dob has springs on the side instead of tension handles. To me tension handles (Starhopper, Saxon) sounds easier for mobility, you simply pick the dob up with both hands by the handle and lift it out to your backyard.

1)But how do you do it with a GS dob with springs on the side? Do you simply lift it by the side platforms? (this sounds rather hard and strenous to me, especially for someone with a bad back.)

2)How much more can I see with the 12' dob vs a 10' dob? will I see more aberrations with a larger apeture dob as well?

Does a larger apeture dob take longer to cool down? (reach ambient temperature)

3)How easy is it to nudge and find objects with a dob? Has there every been a case where a nudge was "too much" and the dob lost the object it was focusing on?

4)Do you ever get fustrated by spending loads of time trying to find something with a dob?

5)Do you think a 12' dob can fit into a Corrolla hatchback?

Clear skies

Starkler (Geoff) · #2 15-09-2005, 12:36 PM

I own the GS 10 inch dob myself.

1: i use a trolley/hand truck to wheel around my dob in one piece at home. When travelling after removing the springs the ota lifts off the base. Splitting the dob into two pieces makes it much easier to transport. I think dissasembling the Saxn dob will be a bit more of a chore.

2:There will be a small subtle difference in brightness which you may or may not notice, and a big difference in weight and portability.

3:Either of these dobs can be easily improved in relation to their alt-az motions. As standard the motions can be a bit sticky, causing overshooting of the target.

4: Reading charts and starhopping is an acquired skill which just takes a little bit of practise. If you never learn these skills what will you do if your batteries go flat in the field or suffer an equipment malfunction.

5: I doubt it very much. The 10 inch will fit into most medium sized cars.

ving (David) · #3 15-09-2005, 12:48 PM

1. dont lift it, get a hand trolley from bunnings ) I think they have handles built into the base tho... well my 8" does.

2. er... can remember numbers exactly but the 12er will let in more light than the 10... noticably.

3. get yourself a map of the sky, learn some constellations and jacks your aunty. there are mods you can do to make the dob move smoother too

4. NO! to me its all about the hunt!

star hopping with the aid of a chart is the way to go (for me).

5. if you lay the seats down it should... measure first tho

davidpretorius · #4 15-09-2005, 01:19 PM

Firstly, do you have a laptop that you can take out to the backyard (great for using programs like starry night) and also is your backyard grass or solid like concrete? I have just bought a 44 gallon drum trolley that is 610mm wide, the dob base is 560mm wide. As i have asphalted driveway, i wheel my dob complete out to the driveway. very easy

springs not a problem
this is the best link i know to help, it also show the difference of a still night vs turbulent http://astronomy.trilobytes.com.au/m...iterseeing.htm
it takes getting used to, everything is upside down and left is right. after a few nights, you have this down pat. yes sometimes i do bump it especially at high magnification, when i am looking thru the finder. The earth rotates quite quickly so you have to follow the rotation. not a major issue for me
not with the dob no, the only way around it is with a "goto" system. I am in the middle of motorizing my dob so i can tell it where to point, but that is not a negative. The excitement i felt tracking down uranus and neptune for the first time by hopping from star to star was exhilarating. My heart was beating fast, i was holding my breath and i punched the sky when i found it. I would not have had those feelings with a goto system.
check you measurements, bintel or andrews should give you the measurements

Have fun

janoskiss (Steve H) · #5 15-09-2005, 01:38 PM

4. Only near zenith. A right-angle finder would help a lot here. You'll want a pair of binos too for wider FOV navigation.

I'm not a big fan of the laptop. Too awkward, bright, needs batteries, can't handle moisture. Prefer planisphere and a charts (in plastic sleeves if need be) and a red torch (LED bike light).

ving (David) · #6 15-09-2005, 01:44 PM

if you dont want to lug a laptop around but like your electronic devices there are programs for PDAs too

Eardrum73 · #7 15-09-2005, 01:47 PM

Hey thanks for the links DPretorius. That really gave an idea of how apeture size can make a difference!
At this stage, I don't have the luxury of a laptop to to link it up and my backyard is grassy and very sloping.....

I would like to get a 12' but it may be too large and inconvienient for me I think, I can see from that almost everyone that responded mounts the dobs on a hand trolley.

So IDEALLY a dob should be mounted on a hand trolley.... this would have to be a downer for me as my backyard is full of grassy slopes. Would travelling through rough terain knock the collimation out? (I guess the question is how easy is it for the collimation to go ajar from slopes? - anyone?)

P.S The trill of hunting down a star sounds like fun

ving (David) · #8 15-09-2005, 02:02 PM

hunting is good!

if you get a handtrolley with inflatable wheels (with the presure let down a bit) it should be ok. but if you are going down this particular road then why not the 12"?

Eardrum73 · #9 15-09-2005, 02:41 PM

I was thinking about that.... But just to lift it out from the house to the trolley in the backyard may be too much in itself...

But a 12 inch sure sounds good!

ving (David) · #10 15-09-2005, 02:52 PM

got a shed to store it in?

davidpretorius · #11 15-09-2005, 03:03 PM

build a shed!

Eardrum73 · #12 15-09-2005, 03:14 PM

Shed? err.... no...
sounds like with all the add ons I might as well go for the mead 10 inch or C9.25 with goto? Probably cost the same at the end.....

davidpretorius · #13 15-09-2005, 03:21 PM

as the base is wood, i would be almost tempted to leave the base in your viewing area and then carry the scope down there and plug in.

the scope tube is not heavy at all. to carry both tube and base together in terms of weight is easy, it is just damn awkward. even if you have a box made up that sits over the base to protect from the elements.

janoskiss (Steve H) · #14 15-09-2005, 03:28 PM

You silly dobbers!

See what you've done! Scaring people with all that nonsense about trolleys, sheds, tyre pumps ...

I have the 8" Dob. It's very easy to move. I have to walk down a flight of stairs with it to get to the back yard and back up the stairs when I bring it in. Given that I can carry the base and OTA (the tube) together, I'm sure I could handle a 10", carrying the base and OTA separately. And I'm neither fit nor strong.

ving (David) · #15 15-09-2005, 03:36 PM

ditto steve, ditto!

8" is really protable hey

rmcpb (Rob) · #16 15-09-2005, 03:55 PM

If you have a dodgey back maybe the 8-10" range is a bit better in the beginning. If you go for the Saxon don't pick it up by the "handles" they are attached to the thin sides and could crease the tube, besides it would be a very awkward way to carry the tube and be a greater strain on your back.

As for moving dobs, pull it apart for anything further than a short walk out the back. Easier on you and less likely that you will have a disaster. The trolley is a good idea around where the terrain is fairly easy going but not for rough stuff. Collimation is easy when you get the hang of it so its not a worry.

I would worry about a 12" in a Corolla!! Cooldown time is longer for each successive size but the use of fans inproves this difference.

Get a Telrad for a dob.

Have fun

davidpretorius · #17 15-09-2005, 03:58 PM

but what about the shed?

Eardrum73 · #18 15-09-2005, 04:06 PM

haha .... what a humourous lot you are!

If I am to go for a dob I would probably get it from Andrews or Bintel. As these two establishments epitomises the virtues of the dob, and thats inexpensive for its apature size and uncomplicated.

but that would mean i would have go for the ones with the springs on either side, I am not sure if removing the tube is an option.... it looks really tough just to try and put the spings on!!! I don't think I would be able to do it on a regular basis.

It sounds more and more like I have to go for an 8 inch dob.... rats! I was really keen on the larger dobs....wanted the extra apeture size.

The other alternative would be to fork out a small fortune for a Mead 10' or C9.25.....

janoskiss (Steve H) · #19 15-09-2005, 04:12 PM

Quote:

Originally Posted by davidpretorius

but what about the shed?

Quiet you!

Quote:

Originally Posted by rmcpb

I would worry about a 12" in a Corolla!!

I've got a 1986 Corolla and I saw a 12" Dob in a scope shop recently. I haven't measured it but I think if I ripped the passenger seat out, and folded the back seat down I think the OTA would fit lengthwise from boot to glovebox.

Might even squeeze one passenger in behind the driver.

Eardrum73 · #20 15-09-2005, 04:13 PM

Its interesting that you say that RMCPB...

The first dob I ever say was the one with the handles on either side.... very similar to the Saxon, probablly rebadge.
The shop guy was showing how easy it is to carry and he was picking it up by the handles!!!! Thats why I assumed that that was one of the ways to move the handle style dob.....

A telrad? Whats that? where can I get that?

I think I will have to surf the web for telrad now