[ingrast (Rodolfo)]

While in quite antipodal time zones, I am also here enjoying southern skys from Uruguay.

I was presented with a Celestron Powerseeker 127 by my son some weeks ago, being this my first telescope. For several years now I have been interested in astronomy, following different venues of information from Scientific American to Astronomy to Sky & Telescope magazines, but had not have direct observing experience untill now.

Introduction over, now the bussines of putting this scope to good use.

First even for a novice, the scope out of the box looked grossly out of collimation, comet like stars and Jupiter a featureless disc casting a long light smear to a side.
I begun to work out a homemade laser collimator out of a scrap lenght of brass, but before procuring a laser pointer to put into it, I noticed the primary collimation screws appart from not very practical to work with at night, did not provide good enough range given the very basic stacked rubber rings included as spring force for backward cell movement. I replaced 2 of the collimation screws and rubber rings with 2 new longer screws fitted with knurled knobs, and inserted springs between the mirror cell and back plate.

Improvement was readily apparent, being able to easilly collimate just looking to stars and adjusting the now much more friendly controls while looking through the eyepiece.

Next upgrade was filling the tripod legs with mortar, and building a wooden spreader with a tension screw conveniently attached to the central hole of the eyepiece holder hole, which turned the tripod itself in a much more stable platform, leaving only the EQ mount itself as major contributor to tube vibration.

I can see right now Jupiter's cloud bands and (very pale) red spot, moon details like Huygen's sword stand out obvious, though stars are not pinpoints either.

The provided eyepieces and barlow are next in my list. The 20 mm piece is probably as per some references I found a Kellner, and more or less decent but definitely on the cheap side. The 5 mm piece by the same token is probably a Ramsden, quite poor in resolution, field of view and eye relief. The 3xbarlow works good in my completely unexperienced eyes, but as I learned is quite far also from being a decent part.
I am considering a 5 mm X-Cell series from Celestron and same brand Barlow, and may be I will go also to a 20 mm one. As far as I know any eyepiece investment is sound both in seeing improvement and as a reusable asset if I later upgrade to a new scope.

Last, and the more serious part where I am unsure about the best strategy.

I learned from previous posts in this forum an other resources, the optical design for this particular scope - Jones Bird - corrects a spherical relatively fast mirror with a combination spherical corrector - focal extender (barlow) built in the focuser drawtube end.

I can either work out a solution like Bucky1379 did, scrapping the original mirror, or I may explore a mirror flexing scheme as detailed by Alan Adler in the Nov/2000 issue of Sky&Telescope. This particular scheme calls for both an appropriately dimensioned pusher ring and puller plate which in theory provides a better shaping for a given mirror size and f/ratio.

The rub is, will this work in the Jones Bird design, given that the corrector lens also compensates for spherical aberrations?

So much for a single post, thanks for any advise and good seeing for everyone.

Rodolfo

PS I may post images of the hacks, a camera support for afocal imaging I also built, and some sky images I shoot though I may probably wait for better performance later.