General Informatoin Useful to Astronomers
Here's where you will find need to know information of all types for telescopes. At this time it is not organized or made searchable, when it reaches un-manageable proportions it will be organized.
Magellan II encoders- HP #HEDM-5500 J06 (you will see another number like 9931A or 9943A, the first pair of digits is the year and the second is the week, so these two encoders were made in the 31st and 43rd weeks of 1999) Despite what the MEADE website says, these are 1024 count encoders not 4096! See this site for a datasheet (PDF file online) on the HEDM/HEDS series encoders. These encoders use Quadrature signaling and produce 4096 counts from the base 1024 counts they produce.
RadioShack.com LEDs- Two very bright very diffuse LEDs are available from the RadioShack.com stores (different than the Radio Shack stores in the malls). They are: 900-6115 (should be the one that's a bit focused) & 900-8700 (very diffused). They are both very bright 5mm LEDs.
Batteries: the Ray-O-Vac Renewals are rechargeable alkaline batteries. They have all the good habits of both Alkaline and NiCad batteries without any of the bad. However they do not last as long as other types of batteries, check your devices often for signs of leakage!!
|Renewal Batteries||NiCad Batteries|
|Discharge curve is nearly identical to regular alkaline batteries.||NiCads will maintain a fairly flat discharge curve but will go "flat" very suddenly when they reach their discharge limit.|
|Do not self discharge when
||Typically will lose 10% of
their charge per month just sitting unused.
||Memory problems beyond belief, NiMhd cells do not have as severe problem, but it still exists.|
|You can use partially discharge the cells and recharge them as much as you want. In fact the Mfr says this will increase the life of the cell.||Partially discharging and recharging these cells will create a (sometimes un repairable) memory that requires cycling the cells.|
|Not suitable for high current drain devices.||Good for high current devices|
|Cheap! Typically a 4 pack of AA cells is $5.00 US||Typically $5 each|