skybadger

I  always thought the definitive source on this was in 'visual astronomy of the deep sky' by Clarke,; basically it doesn;t matter which colour you use as long as its dim and you give your eyes hours to recover from a bright day or make sure you wear sunglasses religiously. 

Hi all 

i noticed that the Perseids combine with dark of the moon phase this year so suggested the family go camping for that weekend. 

it met surprisingly little derision from the wife and grown-up daughter. 

Next step -find a place to visit. 

I'm thinking the New Forest will be chocker that time of year so my thoughts of destination are more like Dorset, Brecons, Swansea. Although there's a site at Newport , IoW that sounds interesting.

Anyone got some campsites you can recommend that support Dark Skies policies while not being too rough and commando ? (Cake and eat it !) 

cheers

Mike

I have a not very old video camera that works on those principles. It was high quality for those days; late 90s I think. 

Progress!

Guider focused

Slit optics cleaned and aligned

Collimator focused and focuser calibrated for sensor distance

Camera fitted with rotator for spectrum alignment

So I seem to be ready to go. I'm using a Loadstar as the guide cam using the reflected image but it seems faint and small of field. How do people fair using this image to solve for telescope pointing. Is there ever enough stars or do I need a dedicated second scope to do the pointing ?  

I'd like to automate this under voyager and I see some stuff there, but if I can reliably use the second scope for precision pointing , I can use the primary camera just for spectra, once I have the offsets worked out. 

The primary is a 12" f9 RC, the secondary scope dual mounted is a 140mm Petzval at f8. 

1 hour ago, mikeDnight said:

Do you know of a source?

https://www.ebay.ca/itm/145087426619?hash=item21c7e2703b:g:cmkAAOSw4r1kbtNB&amdata=enc%3AAQAIAAAA4M4xTRle%2BlYmGkyHRgUjuAHr311TP7g1OUn4wsYtQf3N5YYbt5VWjn58x6RppT4ojAHmtkXDLCvT32pLsncU7cnwCIWd6PvVRQeR%2Fe4kdOt%2BI8hRrc9%2BvXX%2BDv6q9xT%2BwgQvAl%2BYft%2BxaXZPzr8LU%2FvCI648W6m1kfeMOTfvorIzYd09bxxLBYKin313gJbUxHhJvJeUaRBijSls7l3M4vfDl%2FqX8d%2BoLJA882zBYcaUDrczZNpwnrLCBcY0NRLCREUvhukHdCx9RBO1BvADCps%2FnKaOIBsMm5nTlOsu0Je8|tkp%3ABFBMyMyA249i it's from china but if you look on the onstep groups.io board, there are official resellers on there in the US too. 

Also see https://www.terransindustry.com/en-gb

I'm not sure why that's a defect. Unless I'm running the inside of the tube, who cares ?

Mines been out there for 2 years without any issues. The front window is not needed. I did this investigation myself and then just put it up there. 

You can buy onstep systems ready made nowadays .... That will do the job. 

On 28/01/2020 at 20:01, lenscap said:

Correct. Onstep is a stepper motor controller

No longer correct, onstep will support servos as a flavour of onstep X

On 28/01/2020 at 20:01, lenscap said:

I use a toothed belt, smooth side facing the horseshoe and toothed side facing the motor sprocket.

I put the smooth side around the large wheel facing inwards and have two jockey wheels that take the smooth belt , between them is the drive pulley, if you insert the drive pulley between the two jockey wheels, you are pushing on the toothed 'outside' of the belt. 

Fabulous. More than I've seen in one place. 

13 hours ago, Paul M said:

Oh, I thought he'd downloaded some applications from github to make the PC's hotspot;  1) launch on startup. 2) persistent.

I must pay more attention!

No you are right , I was exaggerating for effect. If the persistent hotspot thing did its job, there would be no need for the additional tool he downloads. He does talk about using  a phone or external device to provide the external network that Windows needs. Windows doesn;t actually need it if you set up the right type of hotspot - the one that Windows prevents users from creating manually.is a Wifi direct hotspot. 

The bit he doesn't address is 

1, hotspots get created by default as public networks and these then get clobbered by the firewall. 

2, Using connectify to create the hotspot creates a wireless direct virtual network adapter that presents as a public network. 

The answer to all of this is to create a powershell terminal as machine or domain admin and type this command :

"get-netconnectionprofile -InterfaceAlias "Local Area Connection* 2" | set-netconnectionprofile -NetworkCategory Private" where "Local Area Connection* 2" is the name of the WIfi direct virtual network adapter on my device. 

which changes the type of the wifi network from public to private, has the side effect of enabling remote desktop access through the firewall ( which I assume you have manually enabled for your user account. 

I've tested this through numerous reboots . 

Hope this helps someone else.

Mike

4 hours ago, 900SL said:

It doesn't draw 2A, that's the headroom rating

I run a Slate GL AR 750S with a Mele 2, no issues with windows Remote desktop, draws about 6W in operation

yes but i'd still want to get rid of unwanted external dependencies.

2 hours ago, ONIKKINEN said:

This probably isnt the answer you are looking for, but i use one of these: https://www.amazon.co.uk/GL-iNet-GL-MT300N-V2-Converter-Pre-installed-Performance/dp/B073TSK26W/ref=sr_1_3?crid=3KKIP06AYMDDQ&keywords=mini+router&qid=1684697239&sprefix=mini+router%2Caps%2C274&sr=8-3
Im using a win10 mini-pc and never had any connectivity issues, has really worked without issue ever since i set it up the first time.

i started down that route, i have  one but its 5v 2A and I want to remove it from my power budget and wires nest. I  thought i had this sussed by adjusting the local GP tables but its not persistent.

yep, his answer was to use the hotspot from your phone as the internet connection. Thats  poor answer and the reason for connectify. 

Hi all

 I have a Pegasus Nyx and bought a mele quiet 3 pc as the mount controller for standalone imaging. 

It's been a bit of a mare since setting it up for field imaging; getting a working hotspot from the pc for the mount and laptop to connect to seems to be the hardest part. 

I ended up using connectify to host a hotspot on the pc, removing the win11 issue of Windows disabling the hotspot service if there isn't an internet to connect to. Connectify provides this and starts at boot  but win11 considers this a public network so the existing windows firewall needed updating too to allow access from public networks to voyager and the remote desktop. 

However as the last thing to be be figured, I now find remote desktop keeps getting turned off, presumably by the firewall. 

I've manually updated the local w11  firewall to allow access from public networks for RDP and tested it, but I only find the problem in standalone mode, not when connected to a KVM..

I can ping and curl services on the pc but can't RDP, so have a working network connection. The RDP is refused. 

Anyone got an idea how to make this setting persistent between reboots ? My best idea so far is to enable winrm or ssh access and manually turn it on remotely each time. A lot of a faff...

Thanks in advance 

Mike

I think that's a fair shout re the weight once I get back to spherical. It's clear I overestimated the amount of figuring required to get from spherical to parabola. So I will remove the weights and shorten the wets and test frequently at that point. 

You've also seen the vid of the machine, there's a bit of slop there due to hinges having play. I will be replacing the arms with a bigger mech as I move to the 20" mirrors that should also have far less play but that's what the offset settings are for, to blend and avoid zoning as far as I can see. 

Key for me is to get to spherical again.

So I did a bit more. 

Session details: 

So I think Im quite close to a sphere, maybe with a hint of turned up edge now. 

Next steps - 1/3 centre over centre smoothing to spherical using the larger lap. Once I get there, I'll do a gentle parabolising cos I'm itching to start on the 12" mirrors I have accumulated. 

Where I started the session 15th May 

Session details: 

ie I was using a large swing to provide a chordal stroke across the outer zones with a little overhang

#Result of session: 

Inside focus , ROC and outside focus. 

As an outcome, I moved back towards spherical a bit but need to do more on the outer zones. there is a small hole in the centre and the large central zone is still not quite spherical 

The answer to that is that I spun polished back to near spherical and then set to parabolising again with CoC strokes and ended up over corrected. 

The spin polish intent was meant to find out if that was an effective way to smooth out the surface I had which had becomes very rough and since I was getting nowhere with a 50mm lap. The 50mm lap is just too vulnerable to skipping, even after warm and cold pressing. 

So the images are from the return to spherical and the KE settings are from the result after parabolising again. I used some additional weight on the parabolising strokes so I'll remove that next time around.

The intent now is to spin polish back to spherical ( or to reduce the over correction significantly ) and carefully parabolise again. I have some useful ronchi gratings at last and the foucault readings are now repeatable. 

Cheers

Mike

Found the pics I was looking for.

These were the result of parabolising from spherical using CoC strokes through the centre, starting with large eccentric of 35mm, resulting in 10mm overhang, and reducing through 4 wets down to 10mm or so. 

The 70% zone looks raised and could do with a little scrubbing.

I measured the mirror this afternoon and these were the results. 

So my aim is to return to more spherical again - this is is overcorrected - checkout the knife movement range. Doing so will prove that it is overcorrected and let me start comparing the ronchigrams with RonWin. 

I'll also see if I can lower that outer ridge without lowering the edge. 

Got some images from the 5th May .

Inside focus to outside. Lines are straight until they reach the edge indicating returned to spherical but still with a bit of TDE 'hook' at the end. 

The hill at the 40% zone and the one in the centre are both reduced. Can see the kink at 40%  in the right hand images outside ROC. 

This concentric bulls eye pattern has gone  in subsequent working but no images of that yet. 

The ke does indeed move away from the mirror as the in focus zone moves from centre to edge. That takes about 8mm movement to do that. 

I shall run a smoothing spin polish on it again to return to sphere and very gently correct it this time. 

This is what I mean by getting  experience. I don't recall seeing this sort of advice in books.

Voyager advanced.

Bought into this to get multiple cameras imaging at once. Upgraded to advanced for the powerful sequencer. Got loads of data last year using it to manage the obs. Just as well considering the weather.

Still waiting for the array version  to work with advanced scheduler though. Should be soon. 

Can run two instances, have to run monitor script over the top to run two main cameras in tandem and both be mount and dither aware. I haven't done that yet. 

Been quiet of late due to pressures of work. 

Been working on smoothing the mirror back out using a larger lap which had the effect of taking it back to spherical. 

Since it was now almost all spherical, I started parabolising from the centre outwards and , voila, the tde seemed to be gone. 

Continued a bit more and there it was again but parabolising is in progress. 

Using sessions of 10mins with CoC and inspecting after 4 wets out to the edge. 

Ill post some pics to show what I mean in detail. It'll be a week though, off away again..

Key question for me is, the early  Foucault measurements were high in range and reducing over time. For spherical they are essentially zero. The target readings for my 6" f/5 mirror are 0 to 1.8mm but I get 0 to 8mm. Does this indicate strongly overcorrected or strongly under corrected.? I'm working on the theory that it's under corrected since I need to move knife edge much more to get to the desired zone position on the caustic and if it was over, I'd get there very quickly. 

Thoughts ?

But looks great, didn't say that. Nicely done.