MG01

I was in a bit of a rush recently as I needed a new cat5 cable, so I turned to amazon and ordered a well reviewed 'rhino' brand cat6 cable (couldn't seem to find a lowly cat5e anywhere!)

It's absolutely horrible.  All curled up tight and about as flexible as thatcher on milk.

So I'm hoping someone can point me towards some nice silicone or other flexible cables that will gracefully curve about my rig and not add undue tension to the connectors.

Ta.

So, my 10yo has 'acquired' my old 450d and shown an interest in learning the basics of astrophotography.  

So far he has just been watching various YouTube videos and enjoying playing around with various exposure settings for single shot images.  He's then passed them to me for a little post processing to get some okay starfield images.  However, some of the videos have introduced him to the idea of stacking images, stretching the data etc. and it's left him scratching his head a little.

I remember the confusion when I started and was planning to spend some time with him going through DSS and then photoshop curves and levels etc.  But I wondered if anyone has any experience using things like Siril or APP and if these might be more intuitive for a young mind starting from scratch?

2 hours ago, AstroMuni said:

I set magnitude around 10. Because I use Kstars I have also mapped my horizon so altitude is taken care of. HTH

I hadn't heard of Kstars and have just looked it up...looks like a great piece of software.  I've been using APT and was thinking about trying out NINA but Kstars looks pretty good too.  We really are spoilt for choice with software these days.

34 minutes ago, AstroMuni said:

I am not aware of a site that has a ready reckoner for what you are asking. As the equipment I have is limited, I go about it like this. First get a list of objects that are visible for the period. Make a shortlist based on FOV, magnitude etc and narrow it down to a single object for the night. As an example a faint nebula with Ha is likely to take more subs and this may not fit into a single night. I also set aside time to setup and dismantle scope, sort technical glitches like guiding not working, camera not connecting, the list is endless. HTH.

That's pretty much where I'm at.  I'm very limited with imaging time at the moment as we live in a flat.  Most of our sessions are at star camps or camping trips.  What magnitude limit do you tend to set?  Telescopius has the option to limit on time above a certain elevation which helps too.

Within the capability of astrophotography imaging sensors but specifically the emission lines that we have filters for.  Basically which filters for which targets and which cameras?

Is there anywhere on the interwebs that can help produce a list of targets based upon their electromagnetic spectrum emissions? 

I've been using Telescopius to produce a list of suitable targets based on location and target time above 40° to make sure I have long enough to capture data but I'd like to be able to filter based upon emissions so that I can match up to either DSLR or CCD and choose a suitable filter that isn't going to cut out useful data.  Any thoughts?

On 13/01/2023 at 16:35, doublevodka said:

Have a look at Lithium Iron Phosphate batteries, appear more resilient than lead acid and normal Lithium and as I understand it can go for long periods without charging. Most of the commercially made powertanks now use these, and as a bonus they are much lighter than lead acid

I did but the price put me off a bit.  I was looking at 'golf buggy' batteries and to get anywhere need a 40/50Amp hour at 12v they were getting very expensive.

IN the end I've decided that since I have mains at the sites I use I'm going down the 'protected' mains supply route.  A 30Amp Powersupply in a rugged case (cheaper version of a peli case)

On 13/01/2023 at 14:00, TyWilliams said:

I'm a bit scared as I haven't taken my setup out yet, but I have a pretty good power bank. Its a Kia EV6, an electric car that has 240v out to power my laptop and EQ5 pro mount. Skywatcher 200 newtonian with EQ5 pro goto mount, and bits and bobs to try to get into this fascinating pastime.

I think as elec vehicles grow in popularity we'll see a few used as powertanks...just make sure you don't get yourself stuck without any juice!!

It's an awesome hobby and you're definitely in the right place to find help with your setup if needed....have fun out there! 

4 hours ago, kbrown said:

I used a 42Ah car battery successfully for a while. But since it was just an ordinary lead acid battery, it didn't like to be discharged periodically so much, As a result it started sulfating and it's capacity dropped and dropped over time. So make sure you get at least a deep cycle battery. Also keep it topped up when not in use.

I think having looked into it I'm going to wait until LiPo batteries are a little more affordable.  I'm going to build a field box with a PSU inside and with a long lead for hookups that I can adapt to take batteries when I can afford them.  For now I mainly go where there's power anyway.

That sounds great. Thanks 

I was hoping to get some opinions on the following power supply...https://www.firstlightoptics.com/batteries-powerpacks/nevada-psw-30-25-30a-switch-mode-power-supply.html

In particular I was wondering how hot it ran under smallish loads (5-10Amax) as I'm considering putting one into a waterproof case as an external power supply.  Obviously I'm going to have to provide some ventilation and I'll lose the full waterproof nature, but the plan is to have it on a table near the scope so it would be off the ground.  I'm assuming the residual heat will be enough to prevent dew forming on the case.  The power will be supplied by an RCD protected cord into a NEutrik Powercon true connector on the box.

Thoughts once again kindly appreciated. 

1 minute ago, AstroKeith said:

The one I recommended way back, really does work to the specification and I've measured the negligible  output ripple.

Thanks for getting back to me Keith.  The trouble with that one is that I have no way of wiring the centre pin on the Dell connector.

From what I've read the inside of the ring is +ve and the outside -ve but the pin needs a chip or something, to communicate with the laptop to identify the charger power and set the relevant charging mode.  So I've given up on making one myself this time.  But thanks again for your suggestion.  That unit would have been perfect for a less proprietary connector.

23 hours ago, CCD-Freak said:

Did you search using the phrase "19V computer travel adapter" ???  That is how I found the one I use and it came with adapters to fit a whole slew of laptops and mini PCs. 

Travel adapters typically work fine with voltages as high a 14 or 15v since they are designed to run from car battery systems that charge at a nominal 13.8V.  I use a LiPO4 battery and a power gate to power all my equipment with a power supply so that I have power backup in case the grid goes down.  If I want to image at a remote off grid site I charge the battery with a solar panel. 

 

Thanks John, that's brought up a few more.  I'm slightly concerned that most of them look cheaply constructed.  But it's an old laptop so might take the plunge with one and see how it pans out.

Well I've found the official one... https://www.dell.com/en-uk/shop/cusadpt90wdcauto-airdww/apd/450-15098/pc-accessories#tabs_section !!!

Looks as though I won't be able to use something like this though because the PC plug has a proprietary centre pin that needs to tell the laptop it's a legit power source.  So I might just resort to putting the power brick in a waterproof box.

2 hours ago, AstroKeith said:

I wouldn't go near that adapter. 

a) the cigarette lighter connector isn't reliable enough for a computer

b) The size is too small to handle that sort of power.

c) I have heard that company has some reputation issues. I believe referrals have been made to Trading Standards.

Thanks for the heads up!! Dodged a bullet there!

2 hours ago, Clarkey said:

I have a 12V version of this that seems to be OK. Given it is a sealed unit I cannot be 100% regards reliability, but the one I use works well.

Topteng Waterproof DC 12V to 19V 8A Step-Up Power Supply Converter Voltage Regulator : Amazon.co.uk: Automotive

You would have to wire your own plugs, but not too much of an issue if you can use a soldering iron.

I should be able to reuse the connector from the power brick in theory.  Although I think I read somewhere that the centre pin is used to register the supply as genuine or something like that.  So not sure what it communicates to where, but may need some more research before committing to chopping things up!

1 hour ago, CCD-Freak said:

This is the one I use to power my remote mini PC.

https://www.amazon.com/CASIMY-Universal-Satellite-ThinkPad-Notebook/dp/B09LLQW74N/ref=sr_1_5?crid=4HV5F6OKGNBS&keywords=12v+power+adapter+for+laptop&qid=1655415730&sprefix=12v+power+adapter+for+laptop%2Caps%2C110&sr=8-5

I have a lighter plug adapter right now but I will be putting a Power Pole connector on it once the warranty period is out.   It has adapters to fit many different PCs and laptops.  

 

I might have a look around for something similar in the UK...agree power pole is way to go.  although I'll probably just crimp some rings on as my PSU doesn't have PP connectors!

45 minutes ago, Alien 13 said:

You might find that the laptop will run off the 14V supply directly, lots of mini PCs that use mobile components will run on 12V rather than the 19V specified..

Alan

It's an 11 year old Dell Latitude E6520 and I'm struggling to find the power specs beyond the official brick specs. 

I have found this though, so this may be the easiest option : https://www.pcadaptersdepot.co.uk/dell-ac-adapters-c-122_72/original-19v-dc-adapter-car-charger-dell-latitude-3450-p-117674.html?gclid=CjwKCAiAk--dBhABEiwAchIwkZnSzfbPvsmmrokib33_Slmep2SgCte7QopRWFzwYR6l1auBZUitEhoCG0cQAvD_BwE

20 minutes ago, AstroKeith said:

https://www.amazon.co.uk/LANTRO-JS-Converter-Voltage-Regulator/dp/B0933G42RT/ref=sr_1_5?crid=33DPWES5YG7V&keywords=12+to+19v+dc+converter&qid=1673265414&sprefix=12+to19v+dc+%2Caps%2C63&sr=8-5

that's the ticket...but do I trust amazon with stuff like this? 🤔

4 minutes ago, Dr_Ju_ju said:

something like this https://uk.rs-online.com/web/p/dc-dc-converters/1793346

but the other way around... 😛

2 minutes ago, Cosmic Geoff said:

That seems a lot.  I have two Dell Vostro laptops of different ages, and actually measured their mains power consumption once running.  One (with HDD) consumed  20+ watts, and the other (with SSD) about 7 watts.    For reference, 5 amps at 19.5v = 97.5 watts.  If there is a Dell +12v adaptor, the obvious choice is to use it (and read its spec. sheet first.)

That's a good point.  I was going off the output on the power brick which is 90w at 19.5V, so about 4.6A.  But I guess that is also charging the battery so the output is going to be higher.

I'm trying to put together a power box and would like to provide 19.5VDC at 4-5A for my laptop.  I believe I need some sort of DC/DC convertor but can't for the life of me find anything on RS to do the job.  It will be connected to my PSU which will be outputting close to 14.5V to account for drop in the cable and wanting 13.8V for my camera.

Any suggestions welcomed, or I may just have to buy the Dell 12V adaptor and hope it can handle the extra voltage!

26 minutes ago, teoria_del_big_bang said:

HERE is an old thread that may help and has links within it to other similar threads.

As you will see I built on a couple of years ago and works a treat using a large(ish) leisure battery.
Only real downsides are it is very heavy and needs putting on trickle charge every few weeks even if not used to keep battery healthy and do not run the battery right down when in use so buy a battery bigger than anything you think you may need in a night.

Steve
 

Thanks Steve, I'll have a read through those threads

Thanks Ian, that looks like a solid choice for an off the shelf solution.

Ideally though I'm looking to put something together myself so am looking maybe at golf buggy batteries?  There just seems quite a range and I've no real understanding of what to look for.

I'm starting to plan a powertank project and after some thoughts on battery type and capacity.

I want to be able to run my imaging rig off grid but I'm concerned that infrequent use could be a problem for batteries.

I think i'll need to power the following:

Atik 383 and Lodestar, filterwheel, Eq6, mele quieter miniPC, pegasus UPBv2 and 5" dewband.

Does 6Amps seem reasonable as an estimation of current load?  In which case maybe a 40Ahr battery would provide enough juice for a winters evening?

Would Lipo batteries be the best bet?  I use small ones for RC cars but have no experience of the larger capacity type.  What voltages can I expect?  I know my CCD likes it a little higher than 12v and am a little concerned about voltage drop over a session...especially since loosing a mount board to undervoltage from my old powersupply.

Any thoughts?

On 29/12/2022 at 19:26, Mognet said:

I've not done a huge amount of research so far, but I've looked at a number

These are still in the running for being both affordable and suitable weight/length for my mount:

• Samyang 135 F2
• SkyWatcher Evolux 62ED https://www.firstlightoptics.com/evolux/sky-watcher-evolux-62ed-ota.html
• SkyWatcher Evolux 82ED https://www.firstlightoptics.com/evolux/sky-watcher-evolux-82ed-ota.html
• StellaMira 66mm ED f/6 https://www.firstlightoptics.com/stellamira-telescopes/stellamira-66mm-ed-f6-refractor-telescope.html
• StellaMira 80m ED f/6.25 https://www.firstlightoptics.com/stellamira-telescopes/stellamira-80mm-ed-f625-refractor-telescope.html
• Williams Optics Zenithstar 61 II APO https://www.firstlightoptics.com/william-optics/william-optics-zenithstar-61-ii-apo.html

I've not looked at small fracs for a while, but is there a reason why the designers are favouring R&P focusers over Crayfords?  I've always found R&P to be frustrating to achieve fine focus...not a problem if you have a motor holding it in position, but older R&P suffered from backlash and I remember the crayford on the old ED80's being a godsend when it ruled the entry frac market.

I appreciate that you're maybe after a faster scope than the older 80ED, but it's still a cracking option albeit a little slower...and probably available second hand a quite a saving?

10 minutes ago, cajen2 said:

+1 for a RDF and  a RACI for a Newt. I use the RDF for getting the scope in approximately the right area and the RACI for centralising the target. One thing nobody's mentioned is how easily a slight touch can put finders out of alignment, so it's good having two.

A space-saving mod is to use a twin finder mount. Here's mine:

Nice setup there...Is that the Skywatcher RACI?  I think I'm going to get one of those...a bit more expensive than I was planning on spending this close to Christmas but  it almost feels like an necessity to get the most out of the scope. (at least I can plead to the budget holder that it's for the kids!!) 😆