fifeskies

While that will work it gives no control over the heating straps , ie full on all the time.

You generally need to reduce from full output, mine run around 20% to 40%.

Only higher if very heavy dew on a cold night.

There are several options for in-line control that sit between the PSU and the heating strap itself.

interesting to compare rotation from yesterday

32 minutes ago, Ouroboros said:

I’ve seen those connectors. You reckon they’re OK do you?  I don’t like that they look open at the back end. There won’t be any shock hazard but it’s still open to damp.  I might get some though just to play with. 

Among other ways to seal these other than grease are :-

 adhesive lined heatshrink

(But this makes for a very rigid connection)

Or self amalgamating tape

(This forms a flexible rubber like sealed cover, but remains slightly sticky for a while)

I should have added,  I use a big 13.8v linear supply, so can easily cope with a voltage drop of a volt or so out to the mount.

If your supply only delivers a flat 12v , as CraigT82 has mentioned above you may need to use heavier gauge cable.

Most of the re-wirable adapters can be persuaded to take up to 2.5mm stranded cable, but check the exact ones you are considering , they vary in quality.

Crimped termination sleeves to the cable ends can help to fit them into the adapters.

rewirable adapters allow you to easily make up any length of high current DC cable without having to solder large cables onto small fiddly tabs.

I use 1mm 2-core rubber cable (or 2-core 0.75mm for shorter runs)

It can be a good idea to also use an inline fuse.

Rule of thumb is that focus will change by 1/3 the thickness of the filter , so a typical 3mm filter will add 1mm.

It is because the refractive index of glass is not the same as just air.

To focus with Ha filter and Bahtinov , just push camera to high ISO , just remember to lower it again before imaging.

False colour image derived from Green continuum filter.

Derived from narrowband continuum filter and Baader Coolceramic Herschel, Vixen SD103s

Zoom in for full view

False colour conversion from Green original.

The tripod handset cradle for Synscan (or similar) handsets is not that suitable for fixing to a pier. (and a suitable spare is relatively expensive)

I came up with a very quick and easy way to make a cradle that can either be screwed to something or hung from a hook with some nylon cord.

I used some 4 inch PVC gutter offcut and a heat gun, heat the edge and use a flat piece of wood to press the soft edge against to mould the shape you need.

When I first visited Tenerife there was almost no-one visiting the crater at night so the dark skies were undisturbed.

These days there seems to be a regular set of tourist minibus groups that visit the crater every clear night with their powerful laser pointers cutting up the sky.

Its not just confined to one part of the caldera as the minibus convoy seems to split off to all the best spots with ample parking.

However if you wait it out they are pretty much all gone by midnight.

Anyone else noticed the error in this year's giveaway calender 

30 days hath . ........

(And no it's not on the June page)

+1 for using the UV-IR filter on guidecam

Have one on my ZWO290mm mini and it gave much tighter stars when observed in the PHD2 monitor window than it showed before the filter was added.

11 hours ago, malc-c said:

Most  of the standard type of rechargeable batteries (AAA to D cells) normally have an output voltage of 1.2v and not 1.5.  - So the 8 x AA rechargeable batteries will only give you  9.6v  which is well below the optimum 12v required. 

Since 8 x 1.2 volts is only 9.6 this makes rechargeable batteries replacing a 12v supply slightly tricky.

One solution is the easily obtained 10x battery boxes designed to overcome this , using a flying 12v lead to plug into the mount 

10 x 1.2 volts is of course 12v , just don't mix in any normal batteries with the rechargeable ones.

2 hours ago, lee g said:

I use my Herschel wedge with my skywatcher st120 and this gives great views.

all in all a very affordable solar setup 

 

Is that a 1.25 wedge on the ST120.

Looks like it has used up most of the in-focus so I doubt that the longer path needed by the 2inch Coolceramic will allow it to obtain focus in an ST120 , unless anyone knows for sure that it does.

Nice little solar setup all the same

Just a note , I would remove the Telrad when looking at the sun , you can melt the target screen if the sun is high and strong and you accidently pass the strong sun across the top when aligning the mount , the little lens inside it can focus back into the Telrad

I am using my 2 inch Baader Herschel with my William Optics Zenithstar 61.

There is not enough infocus to use my DSLR with just the 2inch snout adapter so I have taken some photos with my phone.

Very pleased with how well the wedge performs.

I am however thinking of upgrading the scope I use,  a bit more aperture and hopefully with a better infocus range, (I only need around another 20mm at most).

What are others using with the Baader wedge.

2

10inch f6.3, Orion Optics UK

To answer this we need to know what camera it will be going on.

It may be your camera already has a filter (eg if you are using a DSLR).

Most ZWO cameras do not have any filter out of the box , just an anti reflection glass window (AR glass).

In this case a IR/UV can be an advantage depending on the target.

Yes , they compensate for telescope optics such as vignetting and dust on the lenses.

You should not move focus etc before taking the calibration frames as this would change the position of dust motes  relative to the sensor.

Would help to know what you plan to put onto the mount.

Ideal height for a 150 mm f10 refractor will not be the same as ideal height for a 300mm f4 Newtonian.

You may need to think about all the scopes you have and work out what will work for all of them.

Another factor would be the horizon you have from the dome, if you have trees/buildings restricting your view to over 15 degrees altitude this will affect the decision.

Also remember to offset the pier so the dome centre is actually the mount axis crossover in Dec and RA  , this is typically 100mm or so pier offset South for the majority of mounts in Northern hemisphere at Scottish Latitudes.

Just a cautionary note

Useable battery capacity is diminished the colder the battery gets

Either allow for the reduced capacity at low temperature or make some provision to keep the battery warm before (and during) use.

Another version of the Dob size image for you.

Early on with my hobby I used a 200p on an NEQ6 mount which works well if you can put up with the focuser ending up at inconvenient angles.

(Easily solved by rotating the OTA in the mounting rings)

Going from a dob you will need to also obtain the mounting rings and dovetail.

It was actually a very good system , plenty aperture and you see a lot more in a session once the GoTo is aligned.

I also used an EQ"5" type mount but it is on the limit for weight capacity, so the "6" range is far better.

Overall however I would suggest that it is probably better to sell on the entire 200p dob and get something more suited to an EQ mount , Refractor/SCT/ Mak

Coolceramic solar wedge from a member on here.

Wonder when the sun will come back 🤔