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)

Well - since that post I used a moonlit night to hit the drift alignment and PHD2... the scope was heavy south, biased east RA Did two runs of PEC training with PHD2 in charge Managed to get PE down to 0.8 arc min, with peak to peak RMS/PE of 13.81" (according to the Guiding Assistant over 120 seconds). I guess that's not unusual for a Meade by 1am.. Guiding RMS was about 1.52" (not great I know, but at least I've got a decent guiding graph).. Dec line is now dead flat. Increasing RA aggr to 85% seemed to help My only confession is that I instructed PHD to ignore the orthogonality error and assume the axis were perpendicular work in progress... any other suggestions on tweaking the PHD settings? or more PEC training? Philip

hi Michael - this is a really good checklist to go through - thanks for your input. I will report back Dave - it's on an astro engineering mega wedge, on a rock solid pier. Bubble shows level. Have ADM counterweights under the OTA. It 'feels' well balanced (ie. I can put it in any position and keep it still - aside from the intentional east RA bias) The intention is to guide with the LX200 (with a focal reducer), and image with the ZS61 and something like a ZWO 183c (one shot colour).. nothing too complex, just wide field. Philip

hi Michael/Danny - All very good points - and yes, inexperience is an issue. I know my way around the sky, but am no expert in imaging. mainly done easy DSLR stuff to date. I'm sure Chaxastro has a valid personal preference for gear (as do we all).. I'm still fond of the Meade is I've had it so long (and had so many great views) Michael said be specific - so here I go: - It's fork-mounted - counterweighted and balanced well in Dec, biased towards the East in RA (with weights on the forks) - guiding with an old Meade DSI plugged into the LX200, focal reducer of 6.3 - Zenithstar 66 sitting on top in rings - reasonably good drift align by hand (I think).. - Guide rate of .66 (60%) as default - No PEC, no backlash compensation on handset What I've noticed is that I get a considerable drift in RA (tends to be more East); PHD2 throws up an orthogonal error (maybe because of the Periodic error?) and calibration is never good. And then the RA/DEC is all over the place. So there's basic problem. But maybe if I can get it guiding taking 30s-1m subs on a fast refractor won't be too much of a problem - what do you think? Philip

thanks Chaxastro - I'm in Great Missenden. The AZEQ6 looks ideal in fact.. only issue is whether the height of the viewing platform would drop compared to the fork mount (and I might lose some horizon..) will need to measure. thanks for the help! Philip

now I've started looking, maybe even the Sky-Watcher EQ8 PRO head... 🤪

now there's an idea.. looks very capable indeed, and could take the weight. Also Tring Astro is down the road, so that's easy The only mod I'd have to make is to the pier plate Thank you for the suggestion.. any idea how easy it is to remove the OTA?? Best Philip

thanks Chaxastro.. I should have been a bit clearer.. I have a couple of lovely short refractors (ZS66 and ZS61) that I plan to piggy back and shoot through, using the lx200 to guide (with a focal reducer).. so i have the refractors.. it's more the control of the mount that's my issue! Cheers philip

hi All I wondered if the 'Lounge could advise on my situation: I have recently installed a run off shed and pier mount for my 12 -year old 10" LX200GPS. It's a great location - looks south, has a nice horizon, has a warm room with all the cables run under the floor.. nice. Even has a radio, heater and whisky supply (Cadenheads small batch Glenrothes, if you're wondering). I've had some really nice views of Venus, the ISS, some deep sky in Leo etc.. I'd really like to get into imaging (likely on a fast WO Zenithstar mounted on top) beyond DSLR stuff.. But I had a very long and frustrating night last night - my Meade seems unable to track or maintain enough control for PHD2 to calibrate. It's also beginning to lose its GOTO capability (not that I really mind, I much prefer manual). Basically it seems all over the place (although the optics are fine) But as I was trying at 1:30am to make the PHD drift trendline go down for the umpteenth time, I asked myself - am I wasting my time? Life is too short.. I'm loathe to take out the Meade and sell/dismantle having build the obsy around it. What would members advise on next steps - bin the Meade?? Mount the OTA on something else? Buy a new one?? I'm just not skilled enough to open up the Meade and conduct open heart surgery on gears and worms.. sadly. I do love the visual stuff, but I wouldn't mind being able to take a decent widefield image .. Thanks for any suggestions! Philip

thanks Michael - that's a great idea , I'll give it a try philip

thanks very much everyone for weighing in - in answer to Olly - it's mounted on a wedge, pointed reasonably accurate north, although I want to use PHD to refine the pA From what Michael said, I could 'fool' the mount by setting 0h 0m, 0dec, pressing GOTO (without alignment it would presumably go to some random part of the sky), then manually position it myself. The ASCOM link woudl then communicate the false position to PHD2... My reason for the post was that my calibration is getting the error message "too far from the Equator" - or words to that effect.. and failing the calibration. I guess I could just bite the bullet and use the GOTO system...