香港天文論壇

Woo..still no people reply

Jonie

Hi

What is the element to decide how thickness of the glass for primary ?


thanks,
Jonie

Dear everybody,

Fast mirror like F/O:2 or F/O:3?
What is the benifit for fast mirror as a telescopes?

Thanks,
Jonie

您好,
我也有興趣參加,請問如何報名,費用多少?
磨鏡班每次只有二天嗎?

Dear Mr. Chan Yuk Lun,

Thank you,
How to meet you?
May I have your moible number ?
and What metro stop to meet you better?

Thanks,
Chenchi

Dear Mr. Chan Yuk Lun,

Thank you,
How to meet you?
May I have your moible number ?
and What metro stop to meet you better?

Thanks,
Chenchi

Hi,

I do read article by search on Google.
But I can't find answer WHY?
Do you know why Cassegrain telescopes do have longer focal length and have no shorter focal length?

Thanks,
Chenchi

Dear sirs,

I am study Cassegrain telescope's structure.
Does anyone know how the light work on cassegrain telescopes and why Cassegrain have longer focal length?

Does any chinese webiste that I can read and understandd about specification of telescopes if I want to buy.

thanks,
Chenchi

Dear Mr. Chan Yuk Lun,

Happy Chinese New Year!

May I have chance to visit you and ask some questions kindly?

I plan to go HK this weekend and visit you on 2/7 in the morning.
And if I have more questions , I can visit you next days.

Many Thanks,
Chenchi

Dear Mr. Chan Yuk Lun,

Many thanks for your welcome visiting. I will let you know when will I be availabe to go.

About class-
will you have chance to have class soon? I read about the ATM class every year. When will be on 2009?

Many Thanks,
Chenchi

Dear Mr. Chan Yuk Lun, Thanks for your reply! I would like to know more details about the stroke that you do by polishing. How is your way to move the arm? Does your table rotate automaticly or by hand? Is your sub-diameter pitch lap match the surface of glass? Match the saggita of the glass? Also 3...

Dear Mr. Chan Yuk Lun,

I read your article about making 30" mirror by subdiameter tool to polish. What is the stroke of circular stroke move by 17.5" pitch tool?
Center to center or ...

Many thanks,
Chenchi

Hi,

I am very impressed that you make 30" glass.
Do you use sub-diameter to do polishing?
It will be great to hear your experience to polish that big glass.
How is your way to make pitch lap for that big?


Thanks,
Chenchi,Yen

Dear Chan Yuk Lun ,

Thanks for your reply.
Do you know anywebsite to teach how to read ronchi grating?
Such as teach you how to read and supply for what stroke to fix?
My mirror has been figured for long time and line is gone very bad.
Have many zone, I have no idea to figure.

Cheers!
Chenchi

Hello,

I am an ATM in Taiwan. I am making the mirror myself.
but I have problem that my glass has TDE.

How to fix the turn down edge? What is the best way to get "straight" ronchi grating?

Many thanks,
Chenchi, Yen