philipok

hi all I've been taking shots of M45 recently and I've noticed condensation in the inside of my W/O Zenithstar 61, leading to haloes on the brighter stars. the front lens is fine and kept clear with a hairdryer. I have been using a scope coat and I wondered whether that is trapping moisture - i.e the thermal shock of removing it might lead to condensation? After reading other advice I have put the scope in a box with the eyepiece out and dessicant to dry out any residual moisture. I don't currently have a dew heater (on order).. Do members have any other suggestions for dealing with internal refractor condensation? Philipok

thanks Michael - I'll keep updating and see how that works. Waiting for a windless night! best Philip

hi all - I've gone through a number of changes in guidescope configuration and really improved my polar alignment. I've been periodically updating my PEC training on the LX200GPS, but now that I've got decent guide set up does it make sense to clear the PEC and start fresh, or just keep updating the training? cheers Philip

a mini-update on my LX200 tribulations which might give some hope for Meade users. I bought a RVO mini-guidescope (31mm) which has frankly revolutionised my nights out. With an old DSI plugged in it sits on top of the mount next to the imaging scope. Since using that I've found more guide stars, used shorter guide exposures, all the orthogonality errors have gone, polar error is down to sub 1', I've PEC trained the mount, the guiding is fine (fine for Meade I guess, 2" peak to peak error). All this means that i can now take 200s guided subs on the Zenithstar 61. So - all good.. 😀 Highly recommend one of those mini guiders that FLO or RVO sell.

thanks for the advice Michael - I'll get on it the next clear night (could be a while) Appreciate all the guidance Philip

thanks Michael - just so I'm clear - the allen screw on the spring should be screwed further in, but to about 1/16" - i.e pushing the spring tighter?

hi folks - further to your (Dave and Michael's suggestions) I opened up the DEC arm.. looked ok to me (attached pics) - relieved to see I have brass gears.. - cleaned the two gears with a toothbrush to get crud out. the lower one had ever so slightly some left-right play, but I could not tighten the pin that much for risk of damaging the screw - seemed tight already. top gear seemed fine and well held in. But I could definitely see the backlash as I played with the gears manually. The main DEC gear and worm seemed ok. I noticed that when I turned the DEC manually the main gear wanted to push out towards me (in fact it pushed off the clutch plate at one point). not sure whether that's normal - i guess in normal usage the cover is preventing it from moving outwards. Any idea whether it's worth tightening or loosening the rack pin spring screw ? not quite brave enough to remove the mounting bolts and try the second step mentioned in the instructions Michael sent Initial scouting complete.. I'll wait for a clear night and try the guiding again.. Philip

thanks very much everyone - I'll take a look (carefully) and see if I can see any obvious problems

thanks very much Michael - i hadn't clocked the recommendation on exposures in GA By tightening the gears & clutch - is that achieved by opening up the fork arms? or do i need to go into the base plate? philip

btw, here is my PHD2 log from the other night.. it's pretty dire until towards sections 39 and 40, after I'd put in two cycles of PEC training and got the polar alignment down. Also I was losing stars with fogging up of the scope.. I think my problem is I'm giving it enough time to settle - would welcome any comments PHD2_GuideLog_2020-06-01_221045.txt

Dave - i intend to work on it until I get some good results. terms like 'fettling' the gears scares me a bit! i'm not I'm up to messing around with the guts I bought it in late 2006, so I'm assuming it has metal gears rather than plastic (and therefore kits such as the Peterson tune up one are not necessary) Philip

thanks Mark - it's a right old debate.. what I'm after is doing wide field, 30s-1m exposures with my 61mm Zenithstar, so if I can get to that stage I'll be happy. i.e, a step up from my DSLR.. Also I've cemented a massive pier in my obsy for the Meade so it would be a pain to have to change it all around! Philip

btw - have you used Pempro? I downloaded it and pulled the PEC curve from the lx200 - it looked terrible - 100" deviations. But I guess that's the curve that resulted from the 2x training I did ?

hi Michael - thanks for the reply - yes it was based in GA, with me also tweaking the RA aggr up a bit. I'm chuffed the Dec I can leave alone now (switched off guiding Dec at one point). So you recommend shorter exposures.. ok - will try that - maybe 2 secs? Might also update the PEC if I get a nice smooth guiding graph philip

I meant of course - Polar alignment error down to 0.8 arc mins.. attached is a picture of my last graph ( i know people usually post logs)