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30/3 update:
Cloud free and a GRS transit allowed me to compare my Newtonian and refractor side by side. Hopefully this is useful to others seeking to see the spot and maybe not succeeding.
The dob cooled for about 30 mins and collimation was checked and found satisfactory.
10:10pm Jupiter is just emerging from a distant obstruction - looking washed out @ 92x in the dob.
10:20 clear of the obstruction and the GRS should be seen on the limb. Not seen. Equatorial Bands are the only clear surface detail with graduated shades towards the poles. View more washed out at 171x. The dob appears not to be at thermal equilibrium as there are obvious ripples in both infra and extra focus images.
10:30 over to the refractor. GRS immediately seen @89x. Fainter and less intense colour than observed on the 25th. Banding not as distinct.
11:10 GRS is about 1/3 the way across the face. Dob is now less washed out, both the dob and the refractor showing obvious colour - a pale red. (Not russet as described on the 25th). Dob @171x fading in and out with seeing. Refractor @89x stable with stronger colour.
11:22 views in the dob noticeably improved. Either the dob is finally cool or sky conditions have improved markedly. Maybe both. GRS now very obvious (as I know what to look for) but seeing still a little patchy making the focus soften. Contrast still better in the refractor. The Tropical bands do not resolve themselves clearly in either scope.
Dropping to 96x in the dob the view is more stable, less washed out and the tropical bands more distinct, but not sharp.
11:30 GRS on meridian. @171x the dob holds the focus well with pale red colour. Banding still looks somewhat washed out.
When I packed up at ~11:45 the LMC SMC, 47Tuc M44 M41 and the coalsack were all clearly visual objects. The sky looked good - unfortunately I had to get to bed!
So, I can understand why I had not seen the spot to date. It's not as red or as obvious as you might expect in the in dob. It would be easy to miss unless it was right on the meridian and if you did not know how it should look in that scope.
Conditions were clearly not ideal early on in this session, but similar conditions are more the norm here than the exception.
Results do seem to suggest that the smaller refactor certainly wins on contrast, colour rendition and with a smaller aperture is less susceptible to atmospherics at least on such a bright object.
Cheers,
Darren.
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