參考網站:
http://www.dfmengineering.com/cct_20.html
CCT-20 and CCT-24
STANDARD OPTICS:
‧ Our typical 0.5M & 0.6M Classical Cassegrains have an F/3 primary mirror
with an effective ratio between F/8 and F/18. The 125mm field is fully shielded and unvignetted.
‧ Back focus is 28cm from mounting surface
‧ 2 variable, low voltage power outlets for reticles provided on optical tube assembly
‧ 2 AC power outlets on optical tube assembly
‧ Finderscope: 5 in. F/9 with 2 in. dia, 32mm focal length eyepiece and projection reticle
TELESCOPE MOUNT:
‧ 30 in. diameter friction drive in RA and 28 in. diameter friction drive in DEC
‧ Steel mirror cell with multiple 12-bolt patterns per KPNO standard
‧ Tracking accuracy: +/- 0.5 arc seconds in 5 minutes, +/- 5.0 arc seconds in 1 hour
‧ Pointing accuracy (with refraction and alignment correction) better than 30 arc seconds RMS
‧ Variable set, guide and tracking rates: 0 to 4 deg./sec.
‧ Supports 65kg instrument load with CG 36cm behind mounting surface
可觀中心 天文台 20" DFM 卡式望遠鏡