Any reviews on Guan Sheng 10" Dobson from Andrews Communications?

[Draco (Draco)]

Originally Posted by martyn01

DOnt get it he tried to sell me an old model after putting up the price $100, he said it was the newest one on his web site and now when you look at the pic on there the knobs are blacked out and changed watch out from them

Hi Martyn01

Are you referring to Andrews .. that I should watch out for Andrews?

[Rick Petrie]

Originally Posted by Draco

I just re-read the specs for the GSO 10" Dobson from Andrews. It says that it comes with a fan for the primary mirror. Does this mean I have to always run the fan to cool the inside of the tube? (which means I have to get a battery pack when I buy the Dob else I wont be able to use it?)

Hi Niv
The purpose of having a fan on a Newtonian/Dobsonian telescope is to cool or bring the mirror to ambient temperature and this will much improve the viewing through the scope. It helps to eliminate the disturbed air caused by the mirror temperature not matching the air around it. (like heat shimmer coming off a road on a hot day)
You can view with no fan attached, but much better views will be obtained with the fan on all the time while viewing as the temperature of the mirror will adjust to closely match the outside air temperature.
Well worth spending a little for batteries to power the fan.
Cheers Rick

[Draco (Draco)]

Originally Posted by Rick Petrie

Hi Niv
The purpose of having a fan on a Newtonian/Dobsonian telescope is to cool or bring the mirror to ambient temperature and this will much improve the viewing through the scope. It helps to eliminate the disturbed air caused by the mirror temperature not matching the air around it. (like heat shimmer coming off a road on a hot day)
You can view with no fan attached, but much better views will be obtained with the fan on all the time while viewing as the temperature of the mirror will adjust to closely match the outside air temperature.
Well worth spending a little for batteries to power the fan.
Cheers Rick

ah ok. Thanks Rick

[barx1963 (Malcolm)]

Niv
Just to clarify what Martyn is talking about. The GSO scopes used to have metal knobs on their alt axis. These are now in black plastic. If you look at the Andrews website it shows the knobs blacked out, prseumably to represent the black platic knobs.
Andrews don't spend a lot of money on their website, one of the reasons their prices are good IMHO!
I have dealt with Andrews and bought my 12" GSO dob there and have had no issues.

Malcolm

[barx1963 (Malcolm)]

Actually, I disagree with Rick. I ran my fan on the 12" for 30 mins to an hour before observing then turned it off. Once the mirrors is cooled to ambient it should be OK unless there is a significant temp change inside a short period.
My reasoning was 2 part. A) batteries are not cheap and didn't want to run them down over a 5/6 hour session B) there is bound to some minute vibration, after all these are only normal computer fans, so turning off makes sense.
In fact my fan stopped working after a while and I found just putting out the scope for an hour elliminated tube currents.
It is easy to see if you have a warm mirror, a defocused star will show clear ripples.

Malcolm

Originally Posted by Rick Petrie

Hi Niv
The purpose of having a fan on a Newtonian/Dobsonian telescope is to cool or bring the mirror to ambient temperature and this will much improve the viewing through the scope. It helps to eliminate the disturbed air caused by the mirror temperature not matching the air around it. (like heat shimmer coming off a road on a hot day)
You can view with no fan attached, but much better views will be obtained with the fan on all the time while viewing as the temperature of the mirror will adjust to closely match the outside air temperature.
Well worth spending a little for batteries to power the fan.
Cheers Rick

[noeyedeer (Matt)]

there's a fair few reviews of the GSO 10 incher. you can search Google for the bintel (aus) or zhumel(?) (us version). they're basically rebadged GSO's

I'm saving up for a GSO dob from Andrews ... worth the money from what I've seen and read. and the money saved can be spent on upgrades.

Matt

[Draco (Draco)]

thanks Malcolm.

I looked at the Andrews website again and did notice the black paintbrush blob

noeyedeer .. yup me too. GSO 10" for me

[Allan_L (Allan)]

I think the cooling fan comes with a small battery pack that may take a few AA batteries (or the like).

And i agree that viewing with fan off (in most cases) will produce a better (steadier) image.

Rick has a great setup with a vibration free assembly, so he runs his fan continually as an aid to dew deterrent I believe, as well as mirror cooling.

I too have had several dealings with Andrews Communications and found them to be reasonable and honest with me. Luke can be quite helpful. But telescopes is not their core business.
So just don't expect too many frills or whistles. They work to a good price, and not far beyond. Whereas, Bintel may sometimes be a little more expensive, but they have a showroom, and technical staff to provide good customer support, if you need it. Horses for courses.