2007 was the year that I bought my first dual-axis mount: an Orion Sirius EQ-G. This mount is virtually identical to the Skywatcher HEQ5 with the recent motorization. Apart from it being an affordable mount with decent performance, it also features lots of interest from enthusiast amateur astronomers, either eager to enhance the mount's performance (see the EQ6 Yahoo! Group), or even to give it advanced computerized control for free (see the EQMOD Yahoo! Group).

All facts mentioned above have influenced my final decision to get the non GoTo "SynTrek" variant of the Orion Sirius EQ-G (the GoTo version of the handcontroller is "SynScan"). Nine months later I decided to acquire an EQDIR module from Shoestring Astronomy, along with the EQCBL-01 mating cable. I then installed the free planetarium software Cartes du Ciel, the free and standardized ASCOM Platform (free, Windows platform), and the latest EQMOD ASCOM drivers allowed me to control my mount from my laptop. I was impressed by the relative ease with which all was installed and how the hardware and software collaborated without major issues.

The only real problem I witnessed was a mere usability issue: since I observe mainly on a small balcony or on a remote location, the cable connecting the mount to the PC was often in the way. For a permanent setup this most likely is not a problem, but in my case I was thinking in terms of «this can be done in a more user friendly way». Hence I decided to look at wireless solutions to replace the RS232 serial link with the mount.

Note: I will shortly publish updated instructions

I take no responsibility nor do I claim the instructions given below will yield success. The instructions below are only provided for help. Please do not misuse the information provided on this page.

Computation with a true central obstruction of 75mm, allowing for refocus shift

Contents

Central obstruction: 75mm

Computation with a true central obstruction of 75mm, allowing for refocus shift

Contents

Central obstruction: 75mm

This page summarizes the results of a first preliminary study for finding an appropriate cell design for my primary mirror. These studies would noat have been possible without the assistance of PLOP, a free simulation tool for computing mirror deformations by means of finite elements analysis.

The cell designs included in this first study are a mix of readily available designs and other designs I created (either they were described but without a PLOP input file, or they were not described at all).

At last I decided to give the 14" f/5 optics I bought more than 10 years ago a real life: I'll be building an ultraportable dobsonian telescope.

I start with the following parts list which I already have acquired over the years:

Olivier,

Currently 9 languages are supported: English (of course), French, German, Dutch, Portuguese, Spanish, Indonesian, Italian, Russian.

All words are given in English, then they are explained in English, and the translations follow.