Geoff Lister

I have found that my 32mm, 1.25", Plossl EP is fine for most wide-angle views with my Skyliner 250PX 10" truss-tube Dob. I have a 56mm, 2", Plossl which I use very, very, rarely. I am a big fan of the Synscan GoTo. I have been an OAP for a few years, and I would not want to lug anything much heavier from my garage to patio; about 7 metres through a doorway and down a step. Geoff

With mine, the only way that I have found is to slacken the motor's little thumb screw that links the drive onto the flat of the RA axis manual driveshaft. The setup is not "user friendly"! Geoff

A Google of "RS12 pinout" and "RS232" should give you a good idea of pin locations within the connector bodies, particularly to identify "Pin 1" on the RJ12.

Having spent some of my working life designing telecomms equipment, I realise that the Registered Jack "RJ" connector series is a complete minefield. In theory, it should only be used, as defined by Bell Systems, but in the real world, it is used to define connector body size and the number of connector pins fitted in that body. From my understanding, and a quick check on the web, "RJ11" is usually used for 6P4C, and "RJ12" is the same plastic body but 6P6C. The "RS232" (another data standard, but modified, often heavily in terms of voltage range and circuit impedance, by the computer industry) cable supplied with my Skymax and Skyliner Synscan V3 handsets, has an "RJ12" 6P6C connector, and a 3-way cable [ RED - pin2, BLACK - pin3, WHITE - pin5], terminated by a moulded 9-way "D" female connector with connections:- RJ12 9-way D 2 - 2 3 - 5 5 - 3 Geoff

My (limited) experience is unchanged; they both produce good products. Concerning firmware updates; I have not needed to update any of the firmware in any of my systems. I use the "If it isn't broke - don't fix it" philosophy. Most PC/tablet/phone software requires regular updates, often to correct security weaknesses or to add new features. A mature GoTo is stand-alone, so no security problems; and the night-sky object positioning calculations should be good for considerably longer than the useful lifetime of the mount/handset hardware. As mentioned in other threads; for visual astronomy, the optical tube is most important, usually with an Az/Alt mount; for astrophotography, the mount is more important, usually an EQ mount, and usually more costly to get "decent" results. Geoff

A small dab of cyanoacrylate "Super Glue" may do the job if the proper thread-lock is not easily available. Geoff

A few years ago I had similar problems with my 250PX. The fault was a poorly seated ribbon cable connector on the underside of the azimuth control printed circuit board. It was very difficult to spot - I had to remove the board's mounting screws to see the underside. The ribbon cables passed through ferrite rings - probably a post-design modification to pass international EMC tests - and this extra detour made some of the cable runs very tight. Probably the wise option. Geoff

Close. Model sailing yachts. Any battery that can supply sail winch and rudder servo current should be fine for most mounts, as long as the terminal voltage is within the mount's range. Geoff

These are some current measurements that I made on my mounts, including my Skyliner 250PX with Synscan handset. These are some of my power sources:- Most of the time I use the 12V, 2A plug-top supply, at the end of a mains extension lead, with the supply (and lead end) in an old shoe box - to avoid any dew problems. I found that I needed to extend the 12V lead to avoid cord-wrap, and used white, heavy-duty, multi-strand, bell flex - the white shows up better in the dark (reduced trip hazard); and, because bell flex does not need the extra insulation outer sleeve required on mains wire, it is more flexible. Geoff

The 250PX has a relatively narrow field of view. I use my 32mm Plossl (about 50 degrees FOV) for initial alignment and then go for the higher magnifications. Geoff

I have a range of mounts and telescope tubes at my disposal, but the Skywatcher Skymax 127 with Synscan GoTo is the one I use most. It is a good compromise for most targets. I liked it so much that I bought a second one for use in my holiday home in France. If you only want motorised tracking, then the Skywatcher Virtuoso 90 is worth considering. However, the 127 and its Synscan GoTo is more useful to find some of the more challenging "faint fuzzies". Geoff

This gives you an idea of typical current consumption These are my power sources The 6V battery packs are borrowed from my radio-controlled model sailing yachts. Geoff

I use a monopod with my 15x70s. The monopod takes the weight, and I can scan a segment of sky using small body movements. Geoff

This is my 130P on my Skyprodigy mount (similar to AZ-GTI) This gives an idea of a range of interchangeable optical tubes and mounts. The 130P tube will fit on all of these mounts, but the smaller Virtuoso mount will not work with the larger tubes and high altitude targets. Geoff

My 90mm Mak came with the Skywatcher Virtuoso (Dobsonian) mount. Provided that the seeing conditions are reasonable, this little Mak is fine for the Moon, Jupiter and Saturn. The mount gives me AZ/Alt:- (1) full manual, (2) powered tracking, or (3) full GoTo with the Synscan handset from my 10" Skyliner. Again, if seeing conditions are good, and with the aid of the GoTo, Uranus is visible, and different from adjacent stars. With a solar film filter on the front, the 90mm Mak is excellent for solar "white light" observation. Celestron have the 90mm Mak as a spotting 'scope package with 45 degree diagonal and 32mm Plossl eyepiece; designed to sit on a photographic tripod, and will also fit most astronomical mounts. This is a bit of a compromise, as the 40x minimum magnification is a bit high for bird-watching. I prefer Skywatcher's Virtuoso version. Geoff

Hello and welcome to SGL. I use a monopod with my 15x70s. The leg takes most of the weight, and you can use small body movements to scan a small sector of the sky. I find this more useful than the pan-and-tilt head of a tripod. The monopod also works well if I am sitting in a reclining chair - a more natural position for viewing objects well above the horizon. Geoff

Hello, and welcome to SGL. If you look at my signature, you will see that I, too, have the Skymax 127 Mak. This system probably gets more use than all of the others combined. I liked it so much that I bought a second one for use in my French holiday home. I use the Synscan handset for GoTo; it definitely helps find the fainter objects; and Uranus is a definite coloured disk, compared with adjacent stars. Most of the brighter galaxies and nebulae are easy to spot, provided they are not washed out by moonlight or street/house background lighting. The StarTravel 120 does show chromatic aberration when viewing bright objects. I use it if I want a wider view, although the 127mm Mak, with a 32mm Plossl eyepiece, will give a reasonable "wide-ish" view. For visual use, the 120mm will capture roughly 4 times more light than a 72ED. For a wide view, consider a pair of 15x70 binoculars on a monopod. Also worth considering is the Skywatcher Heritage 130P, with its extending tube and Dobsonian table-top mount. It has about the same light-gathering capability as the 127mm Mak., but with its shorter focal length, it gives over double the field-of-view with the same eyepieces. I have used the OTA on my Skymax and SkyProdigy mounts for full GoTo. This is the OTA on my SkyProdigy mount. Geoff

My ST120 was supplied as a package with an AZ3 mount. The rings for the ST120 are bolted to the top plate of the AZ3. This is fine for using the ST120 on the AZ3, but there is no flexibility to use the ST120 on other mounts, or other OTAs on the AZ3. This is my solution:- Dovetail rail with the ST120's rings attached The bolt in the centre, at the right-hand (forward) end of the rail, stops the rail sliding rearwards out of the clamp. Yes. With my modification, the 4 cap-screws are mounted from the ring side, with tapped holes in the rail, and clearance holes added to the rings. If I remember correctly, I mounted the rings on the rail with the 2 large bolts, attached the OTA, drilled 4 pilot hole marks in the rings (being careful not to damage the rail's threads), disassembled and drilled the rings' clearance holes. The tippex marks on the rail and OTA body indicate the balance point for OTA+finder+diagonal+eyepiece (just under 4kg in total). The rail came with 2 photographic tripod mounting tapped holes (1/4" - 20 UNC), and the forward one is close to the balance point; so I could, if necessary, use a photographic tripod and the ST120 (probably a case of "tail wags dog"). This is the reciprocal modification to the top of the AZ3. The original ring mounting hole can be seen off the end of the wooden block. The block is attached to the AZ3 with (shortened) 6mm coach bolts and wing nuts for easy removal - although I have not had to remove them yet. The clamp is attached to the wood block with 3-off size 10 x 1" screws. Geoff

If you remove the rear M6 bolt, but leave the front one, you can slide the dovetail plate rearwards into the clamp; and if the clamp pressure releases slightly, the front bolt will act as a stop, preventing the OTA sliding out completely. This is what I did with my ST120. Geoff

I have just taken some photos Draw tube extended with 1.25" eyepiece adaptor clamp Eyepiece adaptor clamp - screws engage on dovetail slope Draw tube end with internal thread Draw tube end clamp ring clamping ring front and back I hope this helps. Geoff

Hello Leeps, Your A & B look something like these 2" & 1.25" eyepiece adaptors from my 250PX Your C looks like a combination of the top section of my T to 1.25" adaptor and my x2 Barlow. I have found that I need the T-adaptor + x2 Barlow to get enough inwards focus on my 250PX. This is how I use my D3200 in place of a 1.25" eyepiece. Geoff

Hello Gary, This is my Skymax V3 Synscan handset (RJ45) to mount (RJ12) cable, annotated with colours. The cable is the same for my Skyliner mount. Both are Az/Alt, so it is possible that the white core has some function on an EQ mount. EDIT:- I have just done some background research, and I think Peter is right (HEQ5 uses RJ45 to RJ45). Geoff

Yes! It is still a challenge, and the eye relief means that I have to back off slightly, so some form of eye shade is required to see the (slightly) dimmer view; and the extra magnification means that I cannot see the full disk. An observing stool/chair is definitely necessary to help keep your head still. Now all I need are a few sunspots to aid sharp focus. Geoff

(1) I use my x2 Barlow when using my binos with Newtonians, but my Maks (fortunately) have enough focal range not to need the Barlow. The optical path length of the binos is similar to that of a mirror diagonal, so, for my refractors, a Barlow is unnecessary. I may well try my SS60 with a diagonal + Barlow + binos to see if I can be more successful than I was in (3) below. (2) The SS60 requires clear sky, at least in the region around the Sun, so even winter sunlight is strong enough to do damage. Stray light reflections are more of a nuisance if looking in the general direction of the Sun. (3) I find that, even with a diagonal and 32mm Plossl, it is much more difficult, using the SS60, to get the solar image in line with my eye, than using a similar setup with any of my other OTAs, including white light viewing with a solar film filter. I tend to start with my eye about a foot away, move my head around until I can see a red dot in the EP, and, keeping the dot visible, bring my head towards the EP. With the SS60 and binos, I closed eye2, lined up the view with eye1; then whilst trying to hold my head steady, closed eye1, opened eye2 and adjusted the binos to get the image in eye2 - at which point I had lost the image in eye1. I repeated this process several times without being able to get both eyes working together. Geoff

I wondered the same, so I have just tried my binoviewer and a pair of Celestron 32mm Plossls in my SS60. Yes, it is possible to use a binoviewer, but:- (1) I could not achieve focus with the binoviewer in the 90 degree diagonal. (2) Without the diagonal, the EP position means you are looking directly towards the Sun, instead of downwards. I found the (now, upwards at about 20-ish degrees, and worse in the summer) viewing position, literally, a pain-in-the-neck, even with a range of viewing chairs/stools. (3) It was very difficult to get the exit pupils aligned, so most of the time I only had an image in 1 eye. Others may have a more friendly setup but it did not work for me. I will stick with 1 eye + floaters. Geoff