AstroSystems Standard and Premium Quality
Elliptical Secondary Mirrors

• AstroSystems elliptical secondary mirrors are made of fine annealed Pyrex blanks. These blanks are ground and then polished to the exact minor axis dimension.
• Standard quality secondary mirrors are guaranteed to meet or exceed 1/8th wave flatness for sizes under 3", and 1/6 wave flatness for sizes over 3".
• Premium quality secondary mirrors are hand picked and tested for flatness with a Zygo interferometer. Each flat is then numbered and supplied with a photo illustrating the interferometric fringes. Premium quality meet or exceed 1/10th wave flatness for sizes under 3", and 1/8th wave flatness for sizes over 3".
• All AstroSystems secondary mirrors are then coated with reflective enhanced aluminum. This results in reflectivity of approximately 94-96%, and long coating life. These are then over coated to insure coatings endurance.

Size:	1.30	1.52	1.83	2.14	2.60	3.10	3.50	4.00
Weight:	2	2	2	2	3	4	5	7

A, B, & C Dimensions for AstroSystems Spider and Elliptical Secondary Mirrors

Minor Axis	A (in.)	B (in.)	C (in.)	A+B (in.)	A+B+C (in.)	Weight(lbs.)
1.3	3.0	.75	3.25	3.75	7.0	.25
1.52	2.75	.75	3.5	3.5	7.0	.32
1.83	2.75	1.25	3.0	4.0	7.0	.34
2.14	3.35	1.25	2.7	4.6	7.3	.37
2.6	3.75	1.5	3.25	5.25	8.5	.55
3.1	4.3	1.5	3.5	5.8	9.3	.65
3.5	4.3	1.5	3.5	5.8	9.3	.85
4.0	5.0	1.5	3.0	6.5	9.5	1.0
4.25	5.5	1.5	3.0	7.0	10.0	1.1
4.5	5.5	1.5	3.0	7.0	10.0	1.25
5.0	6.0	1.5	3.0	7.5	10.5	1.35

This is an amazing secondary mirror heating system. The "Dew Guard" automatically senses both the air temperature and the secondary temperature, it will then compensate to maintain the secondary at a preset (adjustable) temperature above the ambient air temperature.

Dew Guard gently warms the secondary at 3-4 watts when on "Full"; it has 8 evenly spaced contact points for optimum thermal distribution. The solid state design consumes power only while operating; this can be furnished from any external 12 volt dc power supply, or you can run on a 9v battery in a pinch.