Some PE data....
Tonight I had some success quantifying the PE of the 317 Teeth RA worm gear.
Seeing was very good, high cloud occassionally spoiling it.
Firstly, to minimise any confusion, I refined the tracking rate in my Bartels stepper drive
so that any PE would not have a sky rate error superimposed on it.
Once that was done I had a nice cyclic wobble showing with a 4.5 minute period.
This is the period of one complete worm rev. {1440mins/317 teeth = 4.5mins)
To represent this graphically, a picture tells a thousand words:
I captured a set of long exposures again but deliberately dialed in
some sky rate error so that the wobble wasn't drawn over itself
cycle after cycle.
Pic 1 shows the 4.5min wobble in RA (west is left)
Next I
deliberately dialed in some Polar alignment error, again to
prevent the wobble drawing over itself (Pic 2)
Now the polar alignment error causes the main PE to show better,
still with an approximate 4.5min cycle. Note the drift now in DEC
Pic 3 is all
sky rate and polar alignment errors zeroed again
and
PEC tuned to the 4.5min cycle and
TURNED ON.
Not bad eh?
An open cluster in Norma....I think it is NGC 6067.
The clearest stars I have ever had in an image!
Steve