ASCOM-AWR 7.2 driver.

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I have now downloaded and installed the new ASCOM-AWR driver 7.2. The time [LST] sky and and site coordinates seem to have stabilized now. I keep checking as I wait for the sun to clear between heavy clouds. I am looking at the featureless, apple green sun, with the binoviewers and SC filter. Just for a change.

There has been no point in attaching the camera so far. The cloud is coming from the SE and steadily thickening. I did a Home run. [Park] Then closed down AWR and the laptop and restarted both. All still seems well.

Friday: Overcast with early rain. I keep waiting for visible targets for Goto Slews. The Moon and Sun are approaching each other in the sky but the heavy cloud cover over the last few days isn't cooperating. I haven't even seen the Moon despite staring intently at passing holes in the clouds where the telescopes are pointing.

I can centre the sun in the 90mm with its Baader foil filter cap safely in place. Then slew to the moon and remove the filter temporarily to confirm the moon is centred. Gotos have never been remotely accurate enough, so far, to find daytime planets. Something I have always wanted to try. It was hard enough to find them in the dark with endless corrections required on the paddle after a Goto slew. Finding the moon with the drives was always complete pot luck too.  Using guide stars for synchronisation and checking mounting alignment? No chance! Why have I put up with this crap for so long?

I wish I had the nerve to climb the huge plum trees behind the observatory. If I removed some branches I could see Polaris more often. The sheer height and risks of climbing such long branches puts me off. My longest double ladder reaches only 1/3 of the way. I have no idea if the branches would take my weight. Felling the huge tree would need a big tractor and chain out in the marshy field to avoid crushing my shed and observatory. Several huge branches curve right over the top of my buildings. Their spread must be 60' east to west.  

The dome seams are leaking enough in places to warrant placing a few sandwich boxes on the base ring to keep the timber dry. If only I had known this when I dismissed the fibreglass calf rearing dome on the grounds of weight. The friction wheel drive would easily have coped with that problem. Though getting the dome segments up to the first floor would have required rather more ingenuity.

Bright sunshine after morning coffee found me in the observatory and set up for some H-alpha imaging. Whereupon it immediately clouded over. So I spent the  waiting time emptying a full bucket worth of sandwich box rain collection. And still the sky darkens. Despite being promised sunny periods.

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26th September 2019. Drivers will drive you nuts!

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Thursday: I have been running driver conformance tests without great success. There are too many errors and it usually stops midway. A new ASCOM-AWR driver 7.1 is available and PayPal has accepted my pound of flesh. Hopefully I shall have it installed by this evening.

An older image of a prom which I ran through Registax6.1 using frame by numbers [1500/3000] instead of selecting 50% in percentages.

Some weirdness is going on in my ASCOM-AWR  drive system:

AWR's Declination direction of drive is unstable. It reverses at random times and intervals. Resulting in potentially dangerous, nose-down slews.

The AWR geographic coordinates of my site are unstable. Longitude is cleared to all zeros and West [instead of East] after an overnight shutdown.

AWR's LST indication is unstable.Since LST is calculated from UT and accurate site coordinates this is inevitable.

The geographic coordinates of my site in C-Du-C are unstable. The minutes and seconds of both Latitude and Longitude vanish overnight. Leaving only the degrees intact.

Even after manual correction of these faults the Alt-Az coordinates for the telescope in its easterly pointing, horizontal parking place are pure fiction! Or friction if you prefer!

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25th September 2019 One slew forwards.. two back?

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Wednesday: A grey day with dark overcast and persistent rain if the forecasters are to be believed. Which means I can't use the sun as a target. So I need a fixed test point without a sky object. Polaris is close enough to fixed without needing to see it. Or so I hope. I need to play with the AWR clock to see if it makes any difference in Goto accuracy.

My usual habit is to go out to the observatory in the morning and slew to the sun. I then follow it until lunch time when I shut everything down. This avoids any conflicts if the drive system should throw a Meridian Flip. Though I am still not sure whether it would [or could] do so without permission. 

Anyway, after lunch I start up the system again and send it off to find the sun. Again from C-Du-C with a Goto slew. This always involves a Meridian Flip because the sun has always moved westward of South while I was enjoying lunch indoors. Further study of the IDS Manual suggests that the telescope will not do a Meridian Flip unless the specific button is pressed.

And yes, I have been enjoying a considerable run of sunny days this year. This is Denmark. Not Gravely Blighted. Where it can rain on the latter on any day of the year. Denmark is far more civilised about these things. It lets it rain on the UK first so it uses up its larger dollops of Atlantic weather. So Denmark usually enjoys only the remains of secondhand rain.

So now I need to run some test slews from the parking position to Polaris and back again. Or, I could call Polaris the parking position and send it to either the East [or Western] horizons. For want of any better location. Somewhere which can be easily checked without the normally active sky objects to play with. I don't even need to open the dome for this. Provided I can keep warm and dry.

I have covered all of this before but routines do not exercise the mind as to possible alternatives. Not when one can safely concentrate on the imaging.  So I have to engage my remaining few brain cells in new ploys. For example: AWR needs manual entry of equatorial coordinates if it can't rely on ASCOM & C-Du-C. Where are these coordinates to come from? I don't exactly carry these around in my head. Though, heaven knows, there is plenty of room in there as my ageing brain steadily shrinks. I'll cheat and read the coordinates off the C-Du-C charts but without connecting it.

I spent the morning sending the telescope around an obstacle course between invisible objects. It was past 11am before the sun could just be discerned through the cloud. The telescope missed the target when I slewed to it without an accurate calibration. I synced on the Sun and then sent it to the moon. Which was invisible. Then back to the sun. Which it missed completely. I reset RTC to GMT+1hr. [UT +2Hrs] If only the sky would clear enough to have both the moon and sun available as easy targets on either side of the meridian. It was quite promising for a while but soon became heavily overcast again.

One amusing anecdote: Provided I didn't Sync on any invisible object, I could send the telescope all over the sky. It would then return safely to centre on the Sun. Cloud thinning slowly. I may even see the Moon before it sets this afternoon. Though by then the sun will have crossed the meridian so I won't enjoy a Flip.

I spent the afternoon and evening running tests on the drives. Now I have discovered a new ASCOM-AWR driver is available and have paid for it.

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Tues. 24th September: AWR LST? Or C-Du-C LST?

Tuesday: Back to the observatory to dig deeper on location and time. I used three aerial photography and mapping services to locate my pier inside the observatory to 1/10 of a second of arc. Then added the fractions of a second to my existing site coordinates just for the sake of it.

AWR's LST [Local Sidereal Time] remains a hurdle. AWR shows LST constantly on the IH2 [paddle] screen. The problem is that an online LST calculator and C-Du-C do not agree with AWR by two whole minutes! I've been here before when AWR didn't change for summer time. AWR's RTC [Real Time Clock] had to be changed to bring it into line with reality. Dare I do this with the two minutes?

Local Sidereal Time Clock  An online calculator for Local Sidereal Time.  

In theory, if you place the cursor on the Meridian in C-Du-C it should show LST for the site. Two minutes behind compared to AWR? As was the LST calculator. I cannot believe that a calculator would remain online unless it was useful. i.e ACCURATE!

I had to increase my real Longitude by 0.63° to make the calculator show the same LST as AWR. So there is something very wrong there. If AWR is using the wrong time then it can't locate anything in the sky. Guess what? It can't even find the Sun and the Moon! 

Earlier rain has cleared to bits of blue sky. Lunch over, so it is back to the fray! Wish me luck! I may be some time.

I adjusted the AWR's indicated LST via RTC [Real Time Clock] until I got a match within 5 seconds of the LST calculator and C-Du-C. Then I carefully confirmed the East-> horizontal Parking Position. Before a Goto slew [and Meridian Flip] to the Sun hiding behind thin cloud. Guess what? It missed!

There was no sign of the sun in the Lacerta prism's heat shield port. Usually the bright disk passes across the  heat shield and can be brought back with the control paddle. I repeated the exercise and returned back to Home at intervals during the afternoon without greater success. The promised clearing to sunshine never happened. So I'm back to square one and none the wiser.

I have performed this Flip/Goto slew dozens of times after lunch. Having turned off the drives to avoid a voluntary Meridian Flip in my absence. [Though this has never happened.] The telescope is left pointing slightly east and must be returned Home and registered [calibrated or synced] there before I can start slewing again from scratch. The AWR system doesn't remember where it is following a switch OFF. 

Close clearances and cable dressing do not allow a Meridian Flip without my careful supervision. The big Herschel prism will happily sweep the laptop off the desk if the focuser is left extended. Then there's the big computer monitor jutting from both sides of the huge pier. USB3 camera cables must be detached and rerouted afterwards to avoid unexpected tension during the slew.

It's very odd how the changing seasons exercise different areas of the telescopes' quite considerable envelope. High summer sun or low winter sun may go unnoticed on smaller or shorter instruments. When you are swinging big tubes more than two meters long, with extra "dangly" bits, in a rather limited space, it makes a huge difference.

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AWR/ASCOM drive woes 2.

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My immediate option seems to be an ASCOM Diagnostics & Conform scan for errors. It is cloudy and blowing a gale today so no chance to do any real astronomy. So I might as well sit in the closed dome and see if I can discover anything for myself. In fact I rotated the dome to the west out of the wind. It was bit noisy during fiercer gusts but better than sitting in the dark.

Rather weirdly the Wifi internet returned yesterday when I turned the laptop by 90°. Previously this orientation was very poor. I had been placing the laptop on various boxes. Now the Wifi works perfectly with the laptop lying on the desk top.

Well, I ran ASCOM Diagnostics and Conform. Both showed a clean bill of health. There was a warning on Conform that the telescope would move to many positions during the test. It didn't do anything physical so the test must be a simulation. C-Du-C [Skycharts] behaved itself this morning.

I had been running the serial cable through a USB3 hub until today. I plugged it directly into the laptop to reduce the risk of failure by one more potential step. There was no run-on of the Declination motor either after a slew to the sun. I left the shutters almost closed to avoid the SE wind getting in. It overshot in RA as usual.

Meanwhile I discovered that the telescopes' positions affects the Wifi signal strength as they slew. Makes sense. Reversing the laptop on the desk retrieved the signal. Nuts! Now I need to make a driven turntable for the laptop? Perhaps I can get ASCOM to remotely rotate it to maximise signal strength? Or perhaps not.

Newsflash! With Skycharts turned off AWR sent the telescopes nose down to the SE. Only pulling the power plug stopped it at -30° altitude! The AWR IH2 completely ignored my button pressing. So I sent the telescopes back to the sun and Home again using coordinate inputs to the IH2 and all went well this time.

AWR: Dec drive Direction is still "fragile." I have to reverse it manually via the IH2 at least once a week!

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AWR[Technology]UK ASCOM-AWR drive woes.

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It seems as if my AWR[Technology]UK drive system is not long for this world. It has been a total pain getting it to perform as expected from day one. It couldn't ever manage to remember LST and CET until I changed it manually. Even after that it is rare for it to find any object in a C-Du-C [Skychart] Goto.

AWR has has to be reminded of the parking position every time it is switched on. Surely this should be completely unnecessary in a fixed observatory drive system? Every single time I remind it of the parking position it responds with "Outside perimeter." Whatever that means. The parking position is horizontal and facing east. As recommended in the 70 page manual.

This position can be set extremely accurately and I even use an accurate digital clinometer to confirm the horizontal. The axes are then at a right angle to each other. I also have to Set Parking Position otherwise AWR doesn't understand why I just entered the parking coordinates for the 365th time this year. It requires the extra step or it will never ever return to the Parking Position when you press HOME.

C-Du-C [Skychart] keeps crashing now. I start up AWR then Skychart. The cursor goes to the Eastern horizon exactly as expected when I "Connect Telescope." This should be a nice safe start to my habit of sending it straight to the low Sun in the East as I start my imaging session, but no. It always overshoots in RA and must be brought back with the paddle.

Now the AWR IH2 has taken to bleeping loudly and repeatedly and telling me that "U-step timed out" every single time I turn the system on. To remind it yet again of the same parking position it has enjoyed since day one. And, no, I have no idea what U-step Timed Out means.

Goto slews are now never finished. The Declination motor continues to run at medium speed until something breaks. Or I literally pull the plug out. The IH2 handset proves completely unresponsive to any button pushes during this potentially damaging crisis. Yet it should stop instantly on pressing any direction button on the IH2 handset. Well, it says so in the manual. So it must be true!

It has a habit of losing track these days. For some reason it goes from tracking to not tracking and the handset becomes completely unresponsive until the power is isolated and the whole system restarted from scratch. Of course that means the telescopes MUST be returned to the parking position and the whole palaver started all over again. Only for C-Du-C [Skychart] to crash, yet again and keep repeating error messages but completely refusing to shut down. 

The system has become wayward at tracking too. I have to constantly manage the tracking using the Simple Handset every few seconds. Otherwise the sun sinks out of sight! The mounting hasn't moved since it was installed.

I use a commercial ASCOM-AWR driver which allows computer connection via an AWR supplied serial cable. Allowing me [theoretically] to enjoy planetarium facilities with Gotos to cursor positions. This system has never worked with Stellarium.

What are my options? Paying another £50 for the driver author [Tigra ASTRONOMY] to provide remote support? What if it isn't the driver at fault? ASCOM support forum constantly falls over itself to tell the world its [highly intelligent and competent users] are complete idiots and losers. While THEY [ASCOM] aren't there for supporting anything but ASCOM. And god help you if you can't get ASCOM to play nice with your kit! Because it is ALWAYS your expensive kit which is at fault. It is always the manufacturer who didn't do a proper job in getting their drivers to work with ASCOM.

Obviously I have no desire to start looking for another drive system at this stage. I am too old to start learning how to use Arduino, all its extras and its programming language. I have seen the misery of those who have tried this using far more experience than I  could possibly manage.

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Sunday Solar prom capture and animation first try.

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Having spent Sunday morning running Registax with a 5% increase each time in "Best frames" on the same video I can see no difference. I selected the same video from scratch before each processing. Alignment, Limit & Stacking only then Save image. No wavelets. Just to prove it I made a video of the stills from 5% to 100% using 1 second duration per saved image: This really is a sequence of sequential, still images from 5% to 100% "Best frames."

https://youtu.be/aCzAzZqgzNw

Having captured and quickly processed a lot of videos into stills I centred them in ImPPG and animated the final stills in Photos Video Editor. This is limited to 1 second minimum duration per still image. So you could try going to YT and doubling the speed. All this is very rough and ready as I find my way around the different softwares. The seeing conditions were poor all day.

https://youtu.be/EXweO6Xc_j0

It seems as if my AWR[Technology]UK drive system is not long for this world. It has been a pain getting it to perform as expected. It couldn't manage to remember LST until I changed it manually. Even then it is rare for it to find any object in a C-Du-C Goto. It has to be reminded of the parking position every time it is switched on. Surely this should be unnecessary in a fixed observatory drive system? Every single time I remind it of the parking position it responds with "Outside perimeter." Now it has taken to bleeping loudly and telling me that "U-step timed out." Goto slews are now never finished. The Declination motor continues to run at medium speed until somthing breaks or I literally pull the plug out. The IH2 handset is completely unresponsive to any button pushes. It has a habit of doing that these days. For some reason it goes from tracking to not tracking and becomes completely unresponsive until the power is isolated and the whole system restarted.

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Saturday 21st Sept. Solar: Proms.

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Saturday: Clear start with a high moon. Then it clouded over!

Bright and clear later so it was back to the observatory for some prom imaging. High frequency thermal agitation teased with only brief clarity all day. Still experimenting with camera tilting and image processing.

Tilting the camera pushes the glare off to the side and hopefully right out of the frame. The tilt plate I have has truly awful ergonomics. I ordered a ZWO but received a clone. One where the thumbscrews are far too short and far too close together to allow any useful adjustment. I don't have any suitable 3mm screws long enough for the pull screws. So I used the pull thumbnails for pushing instead. With very long screws for pulling fitted with doubled and locked nuts.

Today's images speak for themselves as mere daubs. There is no subtlety to the clouds-like proms.

I am trying another technique in Registax following expert advice. Usually I use the coarse, wavelet controls in reverse but now I am trying the earlier
sliders instead. Not with great success I might add.

There are two groups of proms on opposite limbs. Both are changing literally before my eyes on the monitor.

I'd like to step between consecutive images to produce an animation of the changes. This means I have to maintain the same image orientation over time and not to swap Barlows in and out. I'd have to use exactly the same settings in Registax to avoid a change in appearance between animation frames.

I fiddle about with the camera and SharpCap settings so often that I would have to set aside a whole, clear day to capture suitable videos at intervals.

There is doubt being expressed over my Limiting myself to so few "Best frames" from my raw videos. I shall have to redo one of my videos in Registax using stepped % of total frames. Earlier on I was advised to heavily reduce the number of "good" frames. Hence my drastic reduction to 5% and even 2% in poor seeing conditions. I really should watch another video on using SharpCap. I just don't have the patience to watch an old one for another 20 minutes.

Click on any image for an enlargement.

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Wednesday 18th An early start on the Moon.

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I woke early so went out to the observatory as soon as I had breakfasted. About 7am the Moon still hung fairly high in the SSW. So I aimed for Plato and was shocked to see the central crater continuously visible despite the awful thermal agitation. Plato was 2" across without the WO 2x Barlow and twice that with it on the nose of the ZWO camera seen on the 27" screen in SharpCap. Nothing I tried in Registax helped to obtain an improved image from any of my videos.

With a few lunar videos safely captured I noticed that the sun was lighting up the garden trees. Now just above the horizon, the thermal agitation of the sun's image was even worse!

Time for my morning walk. I'll see how it all looks later when there is a bit more altitude to play with. There is a low hill to our east so that must affect the seeing. Though the wind is from the west to north west today. Perhaps the wind itself is responsible for the atrocious seeing conditions? Or just a symptom of the weather conditions? The seeing never did improve.

Thursday: I rebuilt the H-alpha telescope. The off axis glare was getting on my nerves. So I dismantled the lot and blacked the shiny bits. The D-ERF cell was still polished stainless steel. Though that was pointing towards the eyepiece end end. So would only receive low intensity reflected light off the front of the etalon condensing lens. The dirty objective was given a wash with lens tissues. Observatories don't protect the bare glass so you should cover it.

Then I arranged two length of timber together. Spaced to simulate the light cone of a 15cm x 120cm focal length. I had been using the 90mm internal D-ERF much too close to the objective. The cell was being illuminated by the bright focused light cone. One complication is the automatic conversion of the 150mm f/8 to f/10 x 120mm. Nevertheless I moved the D-ERF much nearer the etalon until the light cone from the objective fell inside the 90mm diameter. With everything back together I was called in for lunch. More later.

Click on any image for an enlargement.

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16th September 2019 Solar promenading.

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Monday: Lots of cloud but blue patches offer hope. I am set up for H-a imaging but still waiting for a clearing to check for proms at 2 o'clock and 8.00. Gong Ha suggests yesterday's prom is still there at 2.00 on the limb.

I used the paddle to drive around the solar limb with the gain set high enough to show any proms. Eventually there was enough sun to capture some videos. I tried tilting the D-ERF to kill the off axis glare without obvious effect. Then I tried the camera tilt plate with slightly more success.

The seeing conditions are poor again. The image on the left is of the 2 o'clock prom. The others are spread around 8 o'clock. I am struggling against cloud and a milky sky again.

Image orientation can be easily changed by rotating the camera around its axis. To make sense of prominences on a particular day one ought to try to match the positions shown on Gong Ha. I normally use the hours of a clock to remember which prom goes where. The cable exit from the camera body is a handy marker for monitoring orientation.

The next image [left] was taken mid afternoon of the 2 o'clock proms. A detached fringe is just visible at lower right. The poor seeing conditions do not allow fine detail. The image right using 2% of 3000 frames at 120fps with more gentle handling is slightly less crude. There was a definite high frequency vibration to the seeing on the monitor.

Tuesday: Clear blue skies and the promise of proms had me crossing the yard to the dome. No sooner had I set up than the rain started and the temperature dropped like a snowball. I sat there as it reached 46F with hail thundering on the dome and not enough warm clothes. As soon as the racket ceased I headed back indoors to retrieve my winter [workshop] down jacket and to warm up. I have had the black jacket for years after paying about a fiver equivalent in a charity shop. It is big enough to go over any winter clothes, leaks a bit, but is still warm. Brief blue skies keep returning to tease me but I'm not being caught out so easily again.
 

Click on any image for an enlargement.

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130919 Solar proms + Omegon 2" helical focuser.

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I was set up for H-a when my smart, new, Omegon 2" helical focuser arrived. Along with a low profile ZWO snout. I had been sitting on a 2" clamping ring adapter to 48mm thread. Finally I could put it to good use on the tail end of the Omegon. The telescope end was standard 2" push fit straight into the PST etalon, AOK adapter.

The Omegon offered a considerable length of focus range of about 42mm from memory. Allowing me to both fit and remove the 2x WO Barlow to the ZWO and still reach focus. The Omegon is superbly made and has no discernable slop when locked.  It allowed the removal of two 2" x 50mm extensions which always had to be extended out from their sockets by about 12mm. Just to use up some unwanted focal length. Now it all fits snugly together. As is usual with helical focusers it offers a scale for repeatable focus points. Two thumbscrews can lock the focus position when desired. It would be possible to use a motor and belt to drive the focusing barrel. It just needs an anchor for the motor. 

Finally, I was able to focus properly on the 27" screen. Without having to undo thumbscrews and manually slide extensions back and forth. The focusing results were a great improvement but the the thermal effects on the seeing were still no better.

While trying the low profile nose I discovered that the protective filter over the ZWO sensor was badly misaligned. The filter is supposed to lie flat on a rubber O-ring but it wasn't remotely central. I polished off the eccentric, surface ring markings on the filter with a lens tissue. 

On the right I have pushed the final prom image to bring out more detail by virtue of extra "brightness." Sadly it also brought out a lot of "grain" in the form of noise. Darkening the image cleaned up the glare but the prom vanished much more quickly.

These images are with the WO 2x Barlow on the ZWO for 2400mm focal length. The PST etalon lens group alters the focus too. Cropping around the image has also altered the scale.

The prom was highly active and changed rapidly in the run of the morning. Unfortunately the seeing became steadily worse as lots of cloud came over. So later, comparison images were rather poor. [See Left] The sky has now turned milky around the sun and it is mostly overcast.

There was some cloud clearance in the afternoon but the seeing was awful right up to 17.00.

Saturday afternoon I tried to image a small prom at 8 o'clock on the limb but the seeing was awful. As soon as I gave up the cloud cleared. Not that the seeing will have changed. The gusty wind was making the telescopes nod as well. The forecast is for gales tomorrow.

Sunday I shall try different orientations of the dome in the strong and gusty wind. A few teaser holes appeared in the cloud but the sky was milky again. There was a huge difference in brightness of nearby proms. Which made for a messy final result more like a chalk drawing.

Click on any image for an enlargement.
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12th Serptember 2019 Solar? Or cloud watching?

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Thursday: Early sunshine has turned into wall to wall cloud! With only tiny blue patches to tease me.

I keep wondering if a "skeleton" OTA would improve my H-a views. All the important components could be mounted on baffles providing easy access to individual collimation adjustment. Cooling fans blowing across critical components like the internal D-ERF and PST etalon?

No doubt paying greater attention to different software would help. Though, quite honestly, I find them increasingly opaque. Simply remembering the meaning of endless symbols and abstract routines is beyond my powers of retention any more. I'm 72 and not getting any younger.

I keep reading that I should be using a mono camera but costs spiral and I'd need different processing to optimise my results. I read how others struggle to benefit from their investment in costly cameras. The point is: I am supposed to be enjoying all this as a hobby. Not making myself feel stupid because I don't understand. Nor remember everything I should. Am I having fun yet? Some of my PROM images do seem to be almost on a par with other imagers who have a dome full of very costly equipment.

A dome is often stated [slated] as providing inferior images due to thermal turbulence through the slit. Any building will collect the heat of the sun. Though I deliberately chose plywood and timber to achieve maximum thermal neutrality. Albeit with a green dome instead of traditional white. Naughty!

A wider slit might help. As would putting the telescope out on an extended veranda out in the fresh air. I tried opening the double doors out to the veranda but it made no difference to the image except to make the dome very draughty. Or even moving house to a less cluttered southerly rural aspect. Our own home lies to the south of the observatory. Short of painting the southerly roof titanium white there isn't much I can do about that.

I just had a mad idea: Paint the shutters and the area around the open slit white. But park the dome with the rear still painted green towards the road. Then the differential temperatures during solar imaging will be lower. Because the white area will only be turned towards the sun when I am imaging. Perhaps not.

The oft recommended Borg helical focuser seems to have vanished from the European online dealer's websites. Too expensive compared with all the Chinese competition?? Leaving only TS who now want 15 Euros minimum for delivery. They are pricing themselves out of small item, online sales.

So I have ordered a 2" Omegon helical focuser elsewhere with postage only 1/3 of TS' charges. The Omegon offers lots of focusing range so I can probably lose one extender.

The TS short helical focuser was very sloppy even before it fell in half. A single, small pin, riveted into a thin section of aluminium, was the only thing holding it together. Once the pin became loose, as was inevitable as it was rocked from side to side during normal focusing adjustment. There was nothing to stop the pin rising out of its vital, dual purpose location. The threaded portions of the helical focuser then fell apart. A dreadful piece of engineering design! I ought to return it for a refund I suppose.

Pm. After heavy cloud stopped any chance of imaging I took a break until after lunch. Then spent a couple of hours doing visual. I tried out the binoviewer with various eyepieces with and without the 2x WO Barlow in the 7". The 40, 32 and 26mm eps. all provided a full solar disk with room to spare in the field of view. This required I remove the 100mm extension to reach focus. The binoviewer and Lacerta 2" solar prism are effortlessly supported by the FT 3.5 focuser and 2" Baader Clicklock. Even when the binoviewers are sticking out sideways with a pair of 40mm Meade 4000 Plossls.

The WO Barlow provided very large image scale but still nicely sharp on the rippling limb. There was a hint of surface detail but it was fleeting in the thermally disturbed seeing. I had a look in H-alpha using a 90° star diagonal. A few small proms but I didn't push the power any higher than a 20mm ep.

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Thoughts on a further modified PST:

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I need another helical focuser after the TS one fell in half. A conventional focuser won't work because the focusing has to be at the end of the long, PST filter extension. The etalon has to be in the correct position, relative to the focus of the telescope objective. [200mm inside focus.] Then the rest of the PST filters have to be in the correct place relative to the eyepiece to avoid vignetting as the eyepiece reaches focus.

Sunday's proms 080919.

In the unmodified PST the simple, 1.25" eyepiece socket [holder] is part of the ITF and Blocking filter assembly. Focusing is via moving the prism. Which is removed for heavily modified PST, H-alpha systems like mine.

It might be possible to build a framework for the entire etalon/filter chain. Then a normal reflector focuser could sit on a plate on the end to carry a compact focuser in the correct place. I have a cheap 2" Crayford, reflector focuser which fits on a short SCT tubular adapter. This was fitted to a round plate for my 5" home made refractor. Ready made for the job.

I have wanted to have adjusting rods for the internal, Baader D-ERF. This could be tied into the new mods rather than drilling the existing OTA back plate for longer rods. A cooling fan has also seemed worth trying. Probably drawing air downwards from slots or holes around the rear of the objective end of the tube and past the 90mm internal filter. Though this is presently built onto a solid baffle. Which prevents any air movement. A ring of holes could easily be made to allow forced air flow.

The [live] active area of the SharpCap screen, when set to 640x960. Showing the Solar limb with prominences on my 27" AOC monitor. ZWO 120MC USB3 camera with 2x WO Barlow on its nose. 150/8 [120 F/10 equivalent] with internal D-ERF + PST H-alpha etalon and filtration.

If I could get a 6" f/10 objective and full aperture D-ERF I could start from scratch with a whole, new, H-alpha OTA. But think of the cost buying all new components! A fraction of the cost of a commercial, 150mm, solar telescope but still a heavy outlay.

Then there's the option of a Daystar Quark filter instead of the modified PST. I could still use the 6" f/8 with a Quark. All this during a possibly deep, Solar Minimum? Is it really worth it? Are proms alone worth the very considerable investment? Quarks seem to be highly variable in image quality and even in reliability. With tales of returns and fourth and fifth replacements! Making the £1500 investment quite a gamble. Will some completely new, solar filtration system come onto the market? Perhaps thanks to commercial pressures to lower costs during a Solar Minimum? The trend is towards larger apertures, SCTs with full aperture filters. The results can be stunning but at what cost?

Click on any image for an enlargement.

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5th September Whether the weather?

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Thursday 5th I did a little more black matt painting then set up for some solar imaging under blue skies. The cloud and heavy showers continued so I gave up.

Friday: Went up to check the dome and all was dry inside despite the rain. Windy, showers and no sunshine! Gales and torrential rain again in the late afternoon. Went up to check after the deluge and wind with the shutters downwind. Wet under the shutters in the east. I'll just have to close the gap left when the shutters are closed.

The air gap along the outside of the closed shutters allows the heat out in summer. However, the heavy rain is obviously bouncing off the dome surface and up under the shutters. I didn't want to risk a gap between the closed shutters when I built them. It seems I overdid the overall width [when both shutters are closed] by about an inch shared between both. I can only just get my fingertips between the ribs of the shutter and the dome but it's enough to leak during heavy rain.

It was a hell of a job fitting the completed shutters so high off the ground. The heavy-duty drawer slides were inaccessible from inside the dome but needed to be screwed into place just to support the heavy shutters. Catch 22!

The load was highly asymmetrical until all the slides were screwed firmly home and both were parallel AND horizontal. I kept unscrewing them and moving the shutters up and down. I was terrified the shutters were going to fly away and go straight through my shed roof!

Saturday 7th a fine start but steadily increasing cloud cover. Went over to do some H-a solar imaging. 2000 frames each at 60fps in SharpCap. Processed in Registax followed by PhotoFiltre for false colour and resizing. I pushed the image [Right] too far in Registax Wavelets and now it looks too artificial.

Can't see the small proms shown in Gong H-a. They usually show up when I simply increase the gain in SharpCap but not today. [Well, not yet anyway.] I finally found them amongst the glare and added the 2x WO Barlow. Now it has clouded over. And cleared again. Image left is the best I can do under poor seeing and windy conditions. Gave up for an early lunch due to heavy cloud.

Click on any image for an enlargement.

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3rd September 2019 A full day in the observatory.

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Tuesday is forecast wet until lunchtime. I'd prefer some proper light and fresh air from the open observation slit to do any more painting. The darker it gets in there the more light I need! Finished painting the lower panels in between heavy showers.

It soon became impossible to leave the dome open so I spent time confirming the balance of the OTAs was actually almost perfect. I slacked off the clutch screws each time to provide as much freedom as possible. In fact the telescopes still moved under the drives as if the clutches were tightened solidly. Which is nice check of the overall balance in its own right. Any "uphill" imbalance would demand more torque and the clutches would slip.

Then I set about testing the AWR drives using just the AWR IH2 paddle. A 90° slew in RA from E to the Meridian took 110 seconds. Similarly the reverse. This was equivalent to 1.22 degrees per second. While this looks and feels rather slow the huge time saving from accurate Gotos is well worthwhile. Or would be if only I could guarantee closer targetting of my slews in C-Du-C! Long telescopes really don't want to be racing around inside a tight dome if obstructions might intervene. A complete jam will stall the stepper motors but why take the risk?

I fine adjusted the 90mm and its finder to coincide with the 7" refractor. Every little helps. AWR is now bleeping loudly and saying "timed out." Every other message is "outside perimeters." Neither message is mentioned in the 70 page AWR IDS manual.

I spent the entire day up there in the dome. The wireless internet has become intermittent again! Including in the evening until 8pm, as I tried to capture the low, crescent Moon. The seeing was absolutely awful. With boiling, low contrast due to the light sky and constant cloud crossing. Did I mention the gusty wind making the telescopes nod up down?

It was amazing to see the moon so large on the 27" screen even if it was soft and a bit "wobbly." I tried Registax to see if anything would come out of the mess in the videos. The craters were certainly recognisable as such. Though the background was becoming increasingly visible as I stretched the images in Wavelets. Shortening the exposures and taking more frames helped only a little.

Wednesday 4th Sept. Painted the shutter ribs matt black. To hide the ugly fungus staining more than anything else. Quite a struggle to reach so high via stepladders. So I used a straight ladder to lean on the zenith board. There was only one position for the telescopes to allow such a straight shot. There is no torque applied to the dome so close to the centre of rotation. So I was quite safe.

While I was up there I had a look around outside. The image is looking down on top of the dome. Note how poorly the green paint has adhered to the primed plywood. Though I do think the primer is the weak point. The green paint is supposed to last 15 years!

The inside of the dome looks a lot smarter now but it's a bit like painting the Forth Bridge. Always another bit left to paint. Not easy with the light above and black inside but the results are worthwhile if only for cosmetic reasons. Rain promised for this afternoon and it is getting quite windy and darker already. [12.30]

Click on any image for an enlargement.

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