JamesF

22 minutes ago, Davey-T said:

Just searching for a cable, does it need to be straight through or crossover ?

Going into a router then I'd have said straight through.  If it's to another machine then probably crossover.

James

If it's for imaging, do you actually need the pier to be any higher at all?  When I built my observatory I set a mount up on a tripod and looked at wall heights etc. given that I'd probably not want to image anything lower than about 20 degrees and worked from there.  Having a low pier may help with clearance for a roll-off roof.

James

That's a pain.  Are you able to connect from a different device and get a more reliable connection, or does it look like the ASI Air just doesn't have a very good wifi signal?

James

Is this for visual use, or imaging?  For the latter I think my first question would be whether the pier height actually needs to be increased at all.

James

It's not possible to use the wired network to do the update, I assume?

James

Warming up again now.  Still below freezing, but not by much.

James

Well caught.

It got me thinking about how they actually recover the fairings.  I'd not considered it before.  Apparently they have some attitude jets help guide them, and then a parachute.  As the fairing gets close to the surface of the sea, a boat with a huge net on top tries to get underneath to catch it.  There's a brief video here:

Apparently Elon Musk claims it saves them $6m per launch if they use recovered fairings.

James

Here we go:

About a third of the way up the left hand side of the screen, just coming into view from behind the first stage?  It looks as though it could actually be fairly close.

James

Gah!  It's because I typoed the time!  The first one I saw is at 22:38.

James

I can't see it at all now.  Not what I saw before, anyhow.  I should have screen grabbed what I had at the time.  The other fairing half does seem to go through the shot around 22:21 though.

James

2 minutes ago, johnfosteruk said:

This?

Reckon you could be right.

It's on the first stage image more clearly I think.  It's barely there for a second though, so I've not managed to get a screen grab yet.

James

If anyone else does watch, at 20:38 have a look for a white crescent-shape thing that appears on the left hand side of the frame and disappears off the edge of the shot of the first stage.  Blink and you'll miss it.  Is that part of the fairing falling back to Earth do we think?

James

7 minutes ago, JamesF said:

Realised this evening that I missed the Space-X Transporter 1 launch yesterday.  Fortunately it's still on the Space-X website.

There's a lot of waffle at the start.  If you just want to join for the ride, fifteen minutes in is a good place to start.

James

Realised this evening that I missed the Space-X Transporter 1 launch yesterday.  Fortunately it's still on the Space-X website.

James

The resistance calculation looks ok to me.  You can buy nichrome wire in different resistances, so I found it easiest to work out what length I'd want and then find which resistance made the calculation come out with a suitably close length.  For example, an 8" OTA has a circumference of about 60cm.  To have both connections at the same end you'd want about 120cm of nichrome, to make a loop in the heater.  So for 48 ohms total you'd want wire with a resistance somewhere in the region of 40 ohms per metre.  Is 3W enough power though?  For some reason the figure I had in my head was much more than that.

I am reminded of this, which may help out:  https://www.blackwaterskies.co.uk/2013/05/making-your-own-nichrome-dew-heater-bands/

Particularly the spreadsheet linked at the end that does lots of the calculation for you.

I stopped making my own when I found W&W Astro though because they were sufficiently cheap that the faff of buying the parts and making them didn't seem worthwhile.  Unfortunately they appear to be out of stock of heaters for 8" OTAs at the moment.

James

52 minutes ago, Tiny Clanger said:

Or, Gran's favourite, fly papers !

Good point.  I'd completely forgotten about fly paper.  They might catch wasps, too.  Not sure about hornets though.  Probably needs extra sticky fly paper for them.

James

I didn't even know such things were available :)

James

Still above freezing here, but only just.  I don't think it'll last more than another half hour or so given how fast the temperature is dropping.  Definitely going to be a chilly evening.

James

Just had a peek outside.  We have probably 90% cloud cover at the moment.  There's what looks to be clearer sky to the north west, but I'm not sure it's heading in this direction.  I guess that will become obvious fairly shortly.

James

4 minutes ago, Captain Magenta said:

By the time I get to that stage I’m praying for clouds 💤 

I remember one year when we had seven clear nights on the trot here.  My body was screaming to be allowed to get more sleep by the end of it :D

James

I think they must get in around the edges of the rolling roof.  Everything else is pretty well sealed up.  I even have an EPDM "gasket" around the piers where they come through the floor.  I might look at getting some of those draught-excluder "brushes" for garage doors and the like and fitting those around the edges of the roof to seal it more effectively.  I have vents in the walls anyhow, so there should still be sufficient airflow to keep the damp out.

And it would also keep out the wasps and hornets that think it might make a nice home for the summer.

James

12 minutes ago, Yawning Angel said:

if you can get the exposure short enough to keep it stable

Yes, that has always been a bit of a delicate balance when trying to image something as bright as the Moon with a dedicated mono camera.  I might perhaps have a play with different apertures to see what works well.  Obviously the 80ED performs very nicely, but with a narrowband filter I might be able to give my ST120 a go and squeeze out a bit more resolution.  Especially if I try something like the 3.5nm Ha filter I bought recently.

Such a shame there are so few opportunities to experiment at the moment

James

Just now, Yawning Angel said:

Do you go for pure luminance when doing mono, or filtered?

Most recently I've been using a mono camera with an Ha filter.  Though when I say "recent", that has to be taken in the light of the utterly rubbish weather we've had for the last six months

James

And the way the BBC article reads, they're not saying they have to put the fees up because of additional costs associated with Brexit, but mostly "because we can", thanks to no longer being restricted by the EU.  It does look quite cynical :(

James

Definitely a scam, I'd say.  Poor English and proof-reading, text exactly the same as on a number of other sites, no valid contact details, some images that appear to be copied off other websites.  I wouldn't touch it with yours.

James