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Geoff Lister

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About Geoff Lister

  • Rank
    Proto Star

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  • Gender
  • Interests
    Railways (full-size and model), radio-controlled model boats, and astronomy
  • Location
    North Somerset, UK
  1. Most small to medium mounts require a power lead with a 5.5mm OD, 2.1mm ID power jack at the mount end (as shown on each of the power sources in my photo above). It is worth going for the ones with the slightly longer (14mm) outer sleeve, so that the jack makes full contact within the mount's socket. The Skywatcher/Celestron 7Ah power tank is supplied with a lead designed to go between the tank and the mount (have a look at FLO's details on this unit). https://www.firstlightoptics.com/batteries-powerpacks/skywatcher-powertank-7ah.html Geoff
  2. I too, was almost put off astronomy with a Celestron Astromaster 130 EQ-MD, on its equatorial mount, for many of the reasons mentioned above. I then bought the Skywatcher Skymax 127 Mak. with Synscan GOTO, with its Az/Alt tripod mount, and liked it so much that I bought a second one for my holiday home. I sometimes use the Astromaster's 130mm Newtonian OTA on the Skymax mount, if I want a wider field-of-view than I get with the 127mm Mak. When I decided to go for more aperture, I bought the Skywatcher Skyliner 250PX (10" collapsible Dob.) again with the Synscan GOTO built-in. From memory, the base has a diameter of about 53cm, and probably about the same height. The base and OTA are both OK for a short (a few tens of metres) carry, and up or down a few steps - you have to adopt a wide-knee-waddle walking method to avoid hitting your shins on the bottom of the base. Geoff
  3. These are a selection of power sources that I use with my various mounts. Most of the time, I use the plug-top mains supply, but if I want portability, I tend to use the pair of 6V 2600mAh packs borrowed from my radio-controlled model sailing yachts. I have found that the 8/10 cell battery holders tend to give connection problems, often requiring repeated mount alignment sequences. As an idea of current consumption, these are some measurements I made on my mounts. Power bank mAh figures are usually based on the 3.7V internal lithium battery, so, for a 12V output, the "useful" mAh value is about a quarter of the value on the case. Geoff
  4. I'm sorry about the delay in responding, but I have been away for a few days. These two photos show my wedge. The Virtuoso's feet sit against the white blocks, and the clamping bolt, in the left foreground, is a 1/4" - 20 UNC with a converter collar to 3/8" - 16 UNC. The horizontal section has compass and bubble-level, and the bolt head, just in front of the slope, is to attach the base to the tripod of my Skymax 127. The speckled marks on the chipboard are from rain ?. I was able to get the virtuoso to operate in EQ mode, by using the standard Az/Alt setup that would apply at the North Pole (Az calibration set at 90 deg.). Not a masterpiece of design or fancy woodwork, just functional. Geoff
  5. I have the same Skymax 127, and usually start observing with my 32mm Plossl. As I understand it, the 32mm Plossl gives the widest field of view that can be achieved at a reasonable price with a 1.25" eyepiece, and has good eye relief for glasses wearers. The Mak. also works well with the Celestron 8-24mm zoom; particularly to find the best magnification / visual clarity compromise on the planets. The zoom will also work well with the x2 Barlow, if the seeing conditions permit higher magnification. Geoff
  6. Also worth considering is the 90mm Mak on a tracking mount. https://www.firstlightoptics.com/heritage/skywatcher-heritage-90-virtuoso.html The mount works well unpowered, and is frugal on battery power when tracking (release clutches and slew manually to save power). Geoff
  7. I have obviously looked at larger aperture OTAs, but, the 250PX is very capable, and, as an OAP, is at the top end of comfortable portability from garage to patio. Most of the time, I do visual observing, but if I want a little extra, the GP-CAM and Sharpcap's live stacking work for me. Geoff
  8. Hello Mark, The 250PX is worth the money. However, I tend to use my, smaller, Skymax 127 Mak., with the same Synscan control, probably 5 or 6 times more often than the Skyliner. The Skymax, on its tripod, gives me a better view of low-altitude targets, that are obscured by close-by shrubs and fences when using the lower Skyliner Dob. mount. My garden is reasonably well screened from the surrounding streetlights, but security lights and neighbours upstairs lighting can sometimes be a challenge. If the sky is really clear, and preferably with no Moon, the Skyliner's 4x increase in light gathering lets me push the magnification on the more challenging DSOs (+ Jupiter & Saturn, when available at over 10 degrees altitude in a southerly direction). Geoff
  9. It is possible that an internal connector to the control board or motor/encoder assemblies has come adrift. What mount do you have? My Skymax Mak. tripod mount and my Skyliner Dob. base have very different electronics. What power supply are you using? Too high a voltage can cause components to fail, and too low a voltage often causes problems when slewing, including returning to "Park" Geoff
  10. I have a "Virtuoso" app on my tablet. This enables my Skywatcher Virtuoso 90 mount to be controlled using the tablet's Bluetooth interface, and a relatively simple, and cheap, home-built, Bluetooth serial dongle plugged into the (Synscan) handset socket. Recently, Skywatcher produced a WiFi dongle, at over 4 times the cost of the Bluetooth equivalent, together with a "Synscan" app that does not recognise Bluetooth. The "Virtuoso" app was then withdrawn from the Google Play Store, and I cannot locate a legitimate means of continuing to use the Bluetooth control when my tablet reaches the end of its useful life. I have been a customer of some very professional test labs, running early (W 98) versions of Windows on their test equipment control computers, because they could not get hold of plug-in ISA card drivers that would work on NT underpinnings (2000, XP, Vista, W 7, etc.). The test data was then transferred to more modern PCs to produce the regulatory reports. One of the main reasons that Concorde flights ceased was because spares for the electronic components used in the avionics were unobtainable, and the cost of re-design and airworthiness qualification with modern replacements could not be justified commercially. My slide rule does not require updates, as long as I accept that 4 x 5 = (roughly) 19.98? Geoff
  11. I have found that my Skymax 127 with Synscan's tracking (in its Az/Alt mode) is fine for 8-second D3200 stills, webcam videos of Moon, Jupiter & Saturn, and with my GP-CAM using SharpCap's live stacking on my laptop, is fine for the likes of M57. Geoff
  12. Is the problem with the mount's electronics, or the handset-to-mount cable? It is possible to get this sort of fault message if the cable became trapped and damaged in the mount as it slewed to the park position. My Skymax's cable is relatively short, and is prone to cord-wrap if the slew to park is close to 360 degrees azimuth. It is also worth checking that all of the mount/cable/handset contacts are clean. If I have any problems with either of my Synscan setups, it is usually due to a poor contact, often the plug not fully home in the socket. Geoff
  13. My 250PX 10" Dob. is a 2-part carry from my garage to my patio. All of my other setups are portable, and, unlike the 250PX, will fit in my Mazda MX5 roadster. If the seeing conditions are good, I use the 250PX, but most of the time I use the Skymax with the 127mm Mak., and capture roughly a quarter of the available photons. Geoff
  14. +1 for the Heritage 130P. You will see from my signature that I have several setups, but it is the Heritage that I use if I want to start observing quickly. Geoff
  15. The AZ-GTI is the newer design, with the releasable clutches for the 2 axes, so can be used in manual mode, or if powered, pointed manually and still know where it is pointing. It is designed to be controlled by a companion app., running on a smartphone or tablet. It can also be controlled by an optional Synscan handset (£145 + £21 for the interface cable). The Synscan mount is the earlier design, with fixed clutches, so requiring power to make any movement, and is controlled with the handset. I have not found this to be a serious restriction in normal operation. I have 2 of the Synscan systems (UK & France), and 2 Celestron setups, with essentially the same mechanicals but different controls. (1) The Skyprodigy has a built-in Starsense camera, so, once it is properly dark, it can self-align. This works well most of the time, but I can do a Synscan "Brightest Star" alignment roughly 45 minutes earlier at dusk. (2) The Cosmos 90GT WiFi (can be used with an optional [non Synscan compatible] handset), uses another companion app. on a smartphone or tablet. I use my Samsung tablet, but have found the whole setup difficult to use. Perhaps the AZ-GTI is more user-friendly. I found it difficult to locate and use the tablet screen's virtual up/down/left/right buttons, whilst looking through the eyepiece. I prefer the tactile feedback of "real" buttons. I also found, on a couple of occasions, that the WiFi link would drop out, the tablet would re-connect to my home WiFi hub; and the mount would slew at full speed, requiring me to cut power to avoid damage (I subsequently added a power switch to the mount). I do most of my observing from my back patio, so I generally use a plug-top 12V 2A supply. For portable operation, I tend to use a series pair of 6V 2600mAh NiMH battery packs borrowed from my radio-controlled model boats. These have plenty of spare capacity after an evening's observing. The Skymax system comes with a holder for 8-off AA alkaline cells (an expensive power option), similar to the 10-cell holder that I made for the lower-voltage NiMH cells (bottom right). The batteries fit in the little satchel (shown behind batteries, bottom left) supplied with the mount, and I added a stick-on plastic hook to the mount so that the satchel hangs off the mount, moving with it and avoiding cord-wrap. The heavy-duty white bell flex added to the mains PSU's output lead shows up well in the dark, so reducing the trip hazard. Geoff
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