SN design and Paracorr?
Posted 14 July 2005 - 12:59 PM
Posted 14 July 2005 - 02:34 PM
Posted 14 July 2005 - 07:01 PM
The corrector plate in a Schmidt-Newtonian corrects spherical aberration, and flattens the field. There should be no reason to use a Paracorr in that scope. The result would be a less-flat focal plane, and coma added! The Paracorr is for f/3.5-f/6 paraboloidal mirrors in simple newtonians.
Hi! I'd like to hear the experts on this matter. Will a coma corrector like Televue's Paracorr work in a SN optics design? What would be the probable outcome?
Posted 15 July 2005 - 01:58 AM
Posted 15 July 2005 - 05:15 AM
Posted 16 July 2005 - 11:43 AM
Besides getting the mount working up to full potential, you must address these issues: 1) Powermate (if visual is your bag), 2) Finder (if you use one for more than initial star alignment), 3) Dew Heaters (That Schmidt plate dews up at the drop of a hat. Try Dew-Not heater strips with Thousand Oaks controller for less $$$ and lower energy drain over Kendrick and Astrozap. www.dew-not.com Astronomics sells the Thousand Oaks heater controller. It has unique features and is very lightweight.), 4) Carrying case for mount (that declination plastic cover is VERY prone to breaking, and mine has already been replaced by Meade under warranty). A strong cardboard box lined in foam is OK at first, but I bought the JMI case., 5) Better focuser. The best thing is a JMI NGF-55 Crayford. Those that want bang-for-buck will probably end up with a Borg helical like I did. $60 to $100. 6) Heater power supply. I made my own from a Radio Shack 13.8VDC 3A switching power supply and their SLA batteries that are on sale now, and an auto cigarette plug accessory power outlet, plus an in-line germanium power rectifier diode to prevent the power supply from draining the charged batteries in storage and a 25W 8 ohm series power resistor for charging protection (it drops the voltage to around 13.5V at a 25mA trickle charge). You can bypass the resistor with a switch for faster charging after a night of deep drain use. You can mount the whole shebang in a rugged waterproof military ammo can ($5) and rig it up to where it serves as a UPS when you use it at home. It float charges the batteries at 13.5VDC when you use it as a UPS. You always run off the battery for no ripple from the switching PS. There is enough room left in the ammo can for carrying your heat controller, accessory red light (you can build from red diodes and a rheostat and a max current limiting resistor), insulation for battery, bug repellent, etc. More versatile than a Power Tank and funky cool.
Could say more, but no time today for that.