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Oddsocks

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About Oddsocks

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  1. Do you have Photoshop Sara? It’s fairly simple to create .gifs in PS and I have made a few NEO and Lunar gifs over the years in PS 5 & 6. https://blog.hubspot.com/marketing/how-to-create-animated-gif-quick-tip-ht Never tried in PixInsight and there doesn’t seem to be a tutorial on their resources pages but I’ll have a look later this morning when we get back home after swimming.... William.
  2. Unfortunately you can’t tell when buying power supplies from non-electrical specialists such as astronomy retailers etc. The Nevada unit is a mass market general purpose power supply used primarily to power devices in the home or workshop that would otherwise be used in a car or truck, such as a CB radio or portable short wave receiver, coolbox, air jack or tyre inflator etc. I’m always going to be biased after a working life in medical engineering where we have some of the toughest regulations regarding power supplies, particularly in operating theatre environments where as little as 6 microamps of leakage via an intravenous catheter will stop a beating heart. Of course, the power supplies we used in that environment, roughly equivalent in output to the Nevada, cost in the region of €2,000 each and though they still fail occasionally they never fail in a way that is dangerous to the equipment they are powering or the patient. It’s really a question of risk and how much you may be prepared to lose in the event of a failure. I’m currently running three QSI cameras and at nearly £5,000 each plus nearly as much again for the Atlas digital focusers, I would not risk powering them with the Nevada, or an equivalent. I don’t even use the switch mode power supplies that were provided by the manufacturer but I bought ITE & Medical grade rated, 12V 12.5A switch mode PSU’s from Farnell Element14 that cost close to £80 each and for me that was the minimum level of risk I was prepared to take. With a full specification and data sheet provided plus all the relevant UK and EU safety markings I am as sure as I can be that the power supplies I am using offer the best chance of avoiding catastrophic failure and effectively the end of astronomy for me as now I am retired I could not afford to replace any of my cameras or other equipment should the worst happen. When you look at the Nevada unit, for example, you have to ask where is the specification sheet for it and what UK/EU standard markings does it carry? As you say, without opening it up yourself how do you know how well it is built? and the answer is that you can’t and therefore you have to look at where you are buying from, the data sheets provided and the national-international markings it carries. For something that is really quite critical, even though rather boring, I would only be looking at specialist suppliers with full accountability, such as RS or Farnell Element 14 and I would expect to see a full data sheet/product specification. If your observatory is going to be housing something in the region of ~£10,000 - £15,000 worth of equipment all linked to a single £40 power supply, well, do you really feel that is worth the risk or maybe spend up-to four times that for something that is fully compliant with current standards and the higher level of protection that is implied by those standards? As they say, “You pays your money and you takes your chances” (sic).
  3. I remember that Alan. I think part of the composition was CC14, Carbon Tetrachloride, and the propellent was Freon, both banned substances now. If you used the spray for too long the can froze to your fingers. I don't think I would try to repair James's PSU myself, too many bad joints, bad practice and failure points. Not worth the risk, and expense of a mains leakage to the output side destroying everything downstream. At the very least there should be big varistors and/or crowbar diodes on the output but I see none in the pictures. William.
  4. I don't even think it was the apprentice Gina, probably one of the warehouse operatives filling in while the apprentice was on day-release.
  5. It's perplexing how often I see this recommended across the web and even written in published manuals. On the REME sponsored courses I did in Germany back in the late 70's early 80's we were told never to use any type of contact cleaner or solvent on skeleton carbon presets as it softens the carbon bonding agent on the track and within a very short while the preset would fail completely. The general recommendation was to replace a defective preset if possible but if desperate we were instructed to gently lift the wiper from the track and slide a piece of typewriter paper under the wiper, release the wiper back on to the paper and wiggle the preset back and forth a few times to clean the wiper contact, then slide the paper away. We were told that contact cleaner is only for metals, never for carbon or carbon composites, at least, that was the instruction then and I've not seen any changes to the construction of skeleton presets that would suggest it is now acceptable to squirt solvents on to them.
  6. The banding was apparent in mine at an ambient of around +5c and a sensor temperature of -15c. If it is there you will see the banding most clearly in calibrated darks so make a master bias as you have done, you won't easily see the banding in the bias, and use that to calibrate a master dark of at least 50 frames. The banding will then show clearly, if it exists, with your camera. ( my master dark image in the forum post showing the banding was 100 frames @ 300 seconds )
  7. If that is correct Ade it might indicate that keeping the diagonal in the Lunt case as being a possible issue as many foam rubbers outgas Sulphur naturally as they age and Sulphur reacts readily with Silver.
  8. I had the same issue Dave, my filter became completely obscured in a matter of months. I did wonder if the problem was from something in the case outgassing, possibly vapour from the glues used in the case construction or foam lining, possibly even the paint on the OTA. Bresser sent me a replacement filter very quickly, arriving just two days after requesting it, and I now keep the diagonal in a sealed food container with desiccant bags, completely away from the Lunt case and scope. William.
  9. Don't worry Gav, PM sent to Jonk with link to Dropbox files. William Jon. Have sent you a Dropbox link via PM William.
  10. Depends on the design of the regulator James, some older design use series following power transistors and feedback resistors to effect regulation and these 'leak' a very small forward current continually, this will show as a high voltage, above the stated regulation voltage, when no load is applied, your multimeter will have too high an impedance to pull the leakage voltage down but connect a load and the voltage should drop down to the stated level. Try connecting a small, unimportant, device to the output to load the regulator while monitoring with the multimeter. Just a simple 1W resistor of around 220 ohm should load it enough to pull the voltage down for testing. William.
  11. ******* Item sold, listing to be moved to completed section ******* William Optics GT81 Triplet APO. £520. Payment by direct bank transfer, cleared cheque or cash on collection from Christchurch, Dorset. Price includes DPD Local, next-day courier delivery, shipping to UK addresses only. Will reduce price by shipping cost if collecting in person. Thanks for looking... Anniversary edition with back-pack carry case and tube rings. fl = 478mm 81mm diameter fpl53 triplet objective. f/5.9 3.7kg 2"/1-1/4" adaptors Crayford focuser with reduction gear, digital mm incremental movement display and thermometer. Perfect condition. William.
  12. As an additional point that has not yet been discussed...... I too have an HEQ5 PRO, used now just for daytime solar but originally was my mobile setup. The description of mount continuing to move / creep for a few seconds after the drive button is released is one that I experienced with my mount after the first few months of use and was just due to backlash in the worms, more in Dec than in Ra, but present in both, and was completely cured by carrying out the worm mesh adjustment as described in the manual at that time. I remember that this “creep” after the drive button is released was most noticeable with a three star alignment as the mount balance point tended to swing for the final star of the three star alignment and the mount would continue to move on under gravity and mass momentum for a short distance after the drive button was released. From your description of the problem so far it seems you are most likely seeing the normal “running in” of a new mount with softening and redistribution of the worm gear grease and bedding together of the various components, plus the general movement and disturbance to the drives caused by normal setup and tear down for each session. Before sending the mount back I would at least take the motor covers off, check and adjust if necessary the transfer gear mesh tolerances and adjust the worm-gear mesh pressure, this after all, is something that is a normal part of the standard HEQ5 PRO routine maintenance protocol, and used to be documented in the manual, at least the worm-gear adjustment was. The drive motors on the HEQ5 PRO are stepper motors so they can not “creep” with a direct “leakage” voltage applied, they can only rotate when “pulsed” and if one of the buttons were sticking, or the electronics failed and constantly sending drive signals, you would continue to hear the pulses after the drive button was released. If you are seeing continual un-commanded creeping, so that the object will slowly drift out of the frame and never stop and you are sure that polar alignment is good then the last thing to check, or perhaps the first thing to check is, does the mount “creep” with the ST4 guide cable disconnected? It is not unusual for the rather fragile ST4 cables to go faulty, or for a guide camera to fail in such a way that it is continually, or intermittently, sending guide corrections to the mount when not commanded to do so, if you are using “on-camera” relays and the mount’s ST4 port for guiding (rather than EQMOD/pulse guiding) then disconnect the ST4 cable at the mount and check to see if the mount continues to “creep” during star alignment and after slewing, if not then check the ST4 cable for damage and the guide camera for malfunction. HTH. William.
  13. From your description of the problem it seems that the contact area and limited compression range of a standard Viton or Nitrile rubber ‘O’ ring is just too small to accommodate the flex range of your casing when it is bolted together. How about a wide flat gasket cut from closed cell expanded neoprene rubber, with a large compression range and increased contact area it should cope easily with distortion of the casing when bolted together. As long as it is not over exposed to UV it should have a good few years of life. Fairly easy to cut from a flat sheet with a sharp craft knife or scalpel using a printed paper template as a guide. Might be a solution? I have a few offcuts of low density 6mm thick, self adhesive, expanded neoprene sheet here, left over from when I insulated my observatory’s glass fibre dome roof last year, I can put a couple of bits approx’ 300mmx300mm in a postal tube and mail them off to you .f.o.c. Just send me a pm with a suitable delivery address if wanted. Otherwise, here is a link to a set of closed cell neoprene foam sheet gasket material on eBay: https://www.ebay.co.uk/itm/Neoprene-Rubber-Sponge-Rubber-Nitrile-Cork-Sheet-GASKET-Material-Foam/191593795500?hash=item2c9be14fac:g:U1IAAMXQvTlRgzTV William.
  14. Because the edges of the dust artefacts are rather fuzzy then the tiny amount of focus change between filters can be ignored for the flats, as long as the focuser is in roughly the same place when taking the flats as it was for the images then the flats will be fine, the vignetted field too will hardly change, camera rotation is the thing that must be avoided. Problems sometime creep in if you have a mix of non-parfocal filters, i.e. some filters that are 3mm thick and some that are 0.6mm thick and combined with very fast ratio telescopes, then the change in focuser position may be quite substantial and when applying the flats they may just leave very faint ring outlines of the donuts behind. For your current telescope there is no need to worry. The best position to set the focuser for flats is the one you had for luminance as that filter passes all wavelengths and will provide the best 'average' focus position across the rest of your RGB filters. For taking flats in the field consider an A3 or A4 USB tracing panel, search on Amazon or eBay, you'll find several. Lots of folk here on SGL use them, no need for extra power supplies as they are lit by the USB port of your laptop, just add a little extra absorption (paper) to reduce the light output. If using a flats panel then you need to extend the distance of the tracing panel from the opening of the OTA by at least the diameter of the OTA to avoid light from the panel directly entering the focuser port (see below) and if you have a dew shield already that would be sufficient, if you don't yet have a dew shield then quite a few folk here use inexpensive yoga mats from Aldi or Lidl etc for dew shields, wrapped around the OTA and held in place with a bungee strap, then you can place the tracing panel directly on the dew shield with the OTA pointing upwards and take flats right in the field before dismantling the telescope and risk moving the camera substantially. HTH.
  15. Yes, you would normally have a set of flats for each filter as the dust that causes the donuts will be dispersed randomly across all the filters in your system. With a reflector telescope the principle wavelengths for colour should all be bought to the same focal plane so provided you are using par-focal filters then focus should be close when changing between them however if you have any glass in the instrument such as a flattener or reducer then there will be some shift of focal plane between the colour wavelengths and you will need to re-focus for each filter to achieve tight stars in all four channels (LRGB). The telescope will cool gradually during an imaging session anyway requiring you to re-focus periodically so it's easier logistically to just shoot say half an hour of one colour, change to the next filter, refocus, and shoot another half an hour then repeat for the next filter etc until the session is over. Eventually you may decide to add an electronically controlled focuser to your system and that makes things much easier as focus can be automatically carried out at regular intervals and any required focus shift between filters can be programmed into the system enabling you to quickly run through repeating cycles of LRGB filters without the need to manually refocus with each change of filter, handy with our fickle climate and limited opportunities to collect data. I like your new image but perhaps you have set the background level a little too dark and lost just a tiny hint of the galaxy outer 'glow', at least that is how it appears on my Mac, though the forum does mess with the uploaded images and so too does the web browser I'm using so perhaps the image on your local computer is fine in which case you can disregard this comment. Glad the flats worked out for you, look forward to seeing the 'full colour' version... William.
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