Explore Scientific TDM Adapter for Vixen GPDX / Celestron CAM/GT5 Mounts Features...
- This product number is for the adapter only. The information given here is to acquaint you with the TDM unit.
- Compares the signals incoming from the high precision rotary encoder
mounted onto the RA shaft with the time signal of its quartz oscillator
- Fits many popular mounts, including select models from Celestron, Meade, Losmandy, Synta, Orion, Vixen, and Astro Physics
- Any deviations of the angular velocity of the RA shaft from the
prescribed drive rate, are compensated by feedback regulation in real
time by accelerating or slowing down the drive
- TDM allows auto-guider input as well
- Better quality of mounts will also be able to provide higher
accuracy (even less than 1" or 2" total) using Telescope Drive Master
A common struggle in astrophotography
is having proper accurate tracking ability of mounts. Even most mounts
with advanced tracking features still have small periodic and
non-periodic tracking errors, further limiting the length of exposure
depending on focal length etc. Sometimes, it is quite laborious to find a
guiding star in the observed object's region in the sky, which is
bright enough for accurate tracking process and, at the same time, you
surely will not be able to find two tracking periods with exactly the
same shapes for using your PEC algorithm efficiently enough. While
auto-guiding and PEC (Periodic Error Correction) will help compensate
for this, the best option is the "Telescope Drive Master" (TDM).
The
Telescope Drive Master (TDM) consists of two main parts; a high
precision encoder attached to a mount's RA shaft that sends electronic
signals from the encoder to mount's driver. With a ±1 arc-second
tracking accuracy, depending on the mechanical features of the mount
concerned and the tracking correction speed of its driver to be used, a
controller unit with a standard auto-guider input and sidereal speed of
0.5x is compatible with the TDM.
So
far, three types of mechanical adapters have been developed, attaching
the encoder unit to the mount: for Synta (SkyWatcher) EQ6 (or Orion
Atlas EQ-G in the US), Celestron CGE and any type of Fornax mounts.
(However, in the near future more and more new adapters will be
developed and produced for the other popular mounts as well like
Losmandy, Vixen, LX200, etc.) It means that while a typical EQ6 (EQ-G)
mount can easily have 20-30" (or higher) periodic error as "out-of-box
result", Telescope Drive Master can reduce it by more than one order of
magnitude, down to 2-2.5" peak-to-valley total or less, which is better
than the same feature of the very expensive premium category mounts.
Certainly, the better quality of mounts will also be able to provide
higher accuracy (even less than ±1" or 2" total) using Telescope Drive
Master.
How Does the TDM Work?
The electronic controller unit of the Explore Scientific TDM Telescope Drive Master
compares the signals incoming from the high precision rotary encoder
mounted onto the RA shaft with the time signal of its quartz oscillator.
Any deviations of the angular velocity of the RA shaft from the
prescribed drive rate, are compensated by feedback regulation in real
time by accelerating or slowing down the drive. If further correction is
needed because of errors other than periodic drive error (e.g. dirty
bearings, worm gear slipping on its shaft, etc.), the TDM allows
auto-guider input as well.
Which Mounts Does it Work On?
There are adapters which allow the Explore Scientific TDM Telescope Drive Master to fit many popular mounts, including select models from Celestron, Meade, Losmandy, Synta, Orion, Vixen, and Astro Physics.
How Much Better Can My Drive Perform?
A typical mount can easily have 20-30" (or higher) periodic error as "out-of-box result", Explore Scientific TDM Telescope Drive Master
can improve it down to 2-2.5" peak-to-valley total or less, which is
often better than the same feature of the very expensive premium
category mounts. Certainly, the better quality of mounts will also be
able to provide higher accuracy (even less than 1" or 2" total) using
Telescope Drive Master.