EQ5 Pro Goto mount

[wookie1965]

I have had the mount out a few times now and am getting very frustrated. I balance the mount Polar align put weights and OTA  on then check alignment again. Now if i do a 2 star alignment I get caution previous npe applied. If I do a 3 star alignment all successful first couple of objects are in the FOV but not in the centre and then other objects I go to are not even in FOV. I have to realign  but same thing is happens again getting that way thinking of packing in all together. Any help most appreciated.

[happy-kat]

Have you tried a reset on the handset and started again. Do if you can get someone to check the details you then enter in. This reminds me of a post on a star discovery mount and starting entering the settings in from a reset helped.

The mount must be level.

Don't use Polaris to align on and do try to use two stars far apart like one east and one west.

If you use a 25mm to align don't necessarily expect a 5mm to be in centre of fov.

Hopefully you will get more replies.

[wookie1965]

I have reset the handset twice when I do a 2 star alignment I get caution previous NPE applied. 

[geordie85]

After the caution can you still slew to objects and get them in you FOV?

Have you tried changing the npe in your handset to 0?

[Owmuchonomy]

If your main concern is accurate GoTo for observing then don't get hung up on the accuracy of your polar alignment.  Concentrate on doing a 3 star alignment using 2 stars one side of the meridian and one star the other side of the meridian.  The software will then also attempt to correct for any cone error in your set up (you can see the cone error result by checking the menus).  If you can, centre your objects with a low power EP and then swap for a higher power to centre it more precisely.

[wookie1965]

3 minutes ago, geordie85 said:

After the caution can you still slew to objects and get them in you FOV?

Have you tried changing the npe in your handset to 0?

I dont know how to change the the NPE and can slew to objects but gradually each object is further over in FOV until not at all.

[wookie1965]

3 minutes ago, Owmuchonomy said:

If your main concern is accurate GoTo for observing then don't get hung up on the accuracy of your polar alignment.  Concentrate on doing a 3 star alignment using 2 stars one side of the meridian and one star the other side of the meridian.  The software will then also attempt to correct for any cone error in your set up (you can see the cone error result by checking the menus).  If you can, centre your objects with a low power EP and then swap for a higher power to centre it more precisely.

Last night I used Arcturus then Vega then Almach on viewing M81 it was top left of FOV went to M82 it wasn't in FOV. when I align the stars I start off with 25mm then 15mm then 5mm even defocus  so as to get a good circle.

[Owmuchonomy]

They should work fine.  There are some other tricks to employ.  Make sure that the last movement via the keys on the handset is always the right key >.  This will help eliminate backlash errors in your alignment.  Double check your Lat & Long coordinate entry.  What is the cone error you are getting after the 3 star alignment?

[wookie1965]

I have no idea do you mean Mel and Maz if so getting 00.17.49Mel and 00.04.27 Maz.

[ronin]

All sounds as if it should be working. I can only suggest 2 doubtful items:

Is the Longitude displayed  -2  36, or, 2  36 West. Would expect the -ve sign, so -2  36, thought is that maybe you have ended up with a +ve sign. This may not be you as I seem to recall the software did some strange things with the longitude value at one release. (Used 2  36 as Google pin in the middle of the Mersey says 2.6 West). Easy check is to read what is displayed on power up, just check the "-" or West bit not just the numbers.

The other is what tracking rate is set. Although that should not influence the goto and I would have expected a reset ot two to have cleared it to sidereal default.

Is the mount set to 53 North, I seem to recall that the mount starts running out of easy adjustment not very far North of your location.

 

[wookie1965]

Yes mount is set to 53 degree coordinates are 002`44`W   53`25`N does this look right.

[spaceboy]

What ep are you using when the object is outside the fov if you don't mind me asking ?

Goto accuracy isn't 100% perfect every time and often it isn't going to fall dead centre anyway. I always stressed about this with my first goto mount. You also have to take in to account half the targets in the goto data base are non starters as they require dark skies and a large instrument to see. I say this because you may well have the target in the fov but due to LP or the need of a OII/UHC filter the object isn't apparent anyway.

There are a couple things that help. Make sure your mount is level and don't rely on the bubble on the mount as these are not always accurate. Keep your alignment stars under 30° and make sure one star is apposing side of the meridian. Don't think you have to use the first star that pops up in 3 star alignment. Scroll through and choose one that is near to where you plan to observe. I usually go with one in the southern sky.

I have an EQ6 and do enjoy the goto most of the time as it can speed up the amount of objects I can see in a session but in truth I much prefer finding objects myself with an AZ mount a star atlas and rigel finder.

[wookie1965]

Hi Nick,

               I use a 15mm mostly this is usually great for globular clusters and nebula`s (M57) another user on here Cotterless45 helped me out said why i have light pollution I should stick to globular clusters the bright nebula`s  and double stars so that is what i have been concentrating on although when I had my 150p on EQ3_2 mount I got M81 and M82  in the same FOV I wanted to see these in the 200p I use now had no success. By the way i have done the electrical trunking mod works a treat.

Paul

[spillage]

I have the same mount.

 

Polar align the mount roughly.

run the 2 star align

run the polar align

run the 2 star again

maybe do another polar align.

(do what you are doing by putting the alignment star out of focus. I just normally use a 25 or 20 ep)

 

I find that this will put you target central.

I just ignore the npe.

 

I am not worried about when I add the scope and balance.  I do always use the up and right arrows to do the final alignment adjustments.

By the way what is the trunking mod you have done.

 

Cheers,

Spill.

[happy-kat]

11 hours ago, wookie1965 said:

Yes mount is set to 53 degree coordinates are 002`44`W   53`25`N does this look right.

From reading another post these should be entered in degrees, minutes and seconds and not in decimal if you had used decimal.

Date format is mm dd yy

[wookie1965]

1 hour ago, happy-kat said:

From reading another post these should be entered in degrees, minutes and seconds and not in decimal if you had used decimal.

Date format is mm dd yy

Yes they are it was just away of showing what is typed in and yes date is in that way.

 

[spaceboy]

18 hours ago, wookie1965 said:

Hi Nick,

               I use a 15mm mostly this is usually great for globular clusters and nebula`s (M57) another user on here Cotterless helped me out said why i have light pollution I should stick to globular clusters the bright nebula`s  and double stars so that is what i have been concentrating on although when I had my 150p on EQ3_2 mount I got M81 and M82  in the same FOV I wanted to see these in the 200p I use now had no success. By the way i have done the electrical trunking mod orks a treat.

Paul

 

Bear in mind the FOV in a 15mm 60° eyepiece using the 200P is 0.9° and the same eyepiece in the 150P is 1.2°

As mentioned before goto gets you on target but depending where your alignment stars are determines the accuracy of the GT in that area of the sky. Not every object will fall dead centre of an eyepiece but if they fall outside the FOV of your finder that's when you need to start stressing. Another tip I forgot to mention is to get yourself a radio controlled clock and use that every time you set up your mount. This ensures your input time is accurate each time.

 

[cotterless45]

Yo Paul,

Having gone through all this with the mount, I can only think that the Newt is throwing out your target accuracy by cone error. This may be compounded by any PEC error. I use a Newt differently from a frac on a GOTO mount. Just set up the ep to observe one area . Then polar align, then align just one one star, say Deneb for Cygnus. I hate spinning the ota even when I've got it level before going onto another area of the sky.

I'm sure it's the Newt. With a frac I can get targets in the fov at x200, usually spot on. Your lost findings sound very similar to my experiences . It's hard on your own. We have a great Astro club with knowledgeable practical members who can fix and sort problems. I'll try and find some other opinions,

Nick.

[wookie1965]

On 17/08/2016 at 23:46, spillage said:

I have the same mount.

 

Polar align the mount roughly.

run the 2 star align

run the polar align

run the 2 star again

maybe do another polar align.

(do what you are doing by putting the alignment star out of focus. I just normally use a 25 or 20 ep)

 

I find that this will put you target central.

I just ignore the npe.

 

I am not worried about when I add the scope and balance.  I do always use the up and right arrows to do the final alignment adjustments.

By the way what is the trunking mod you have done.

 

Cheers,

Spill.

I will do that and try it thank you I got a kit off ebay to make my own jubilee clips as i could not find any big enough another SGer on here (Spaceboy) said use electrical trunking make the action smoother. Instead of paying out for scope rings so can rotate the OTA when viewing this does the exact same thing for half the price if not more jubilee kit cost £2.65 and trunking was £5. great mod.

[wookie1965]

On 18/08/2016 at 17:19, spaceboy said:

 

Bear in mind the FOV in a 15mm 60° eyepiece using the 200P is 0.9° and the same eyepiece in the 150P is 1.2°

As mentioned before goto gets you on target but depending where your alignment stars are determines the accuracy of the GT in that area of the sky. Not every object will fall dead centre of an eyepiece but if they fall outside the FOV of your finder that's when you need to start stressing. Another tip I forgot to mention is to get yourself a radio controlled clock and use that every time you set up your mount. This ensures your input time is accurate each time.

 

On that picture M13 would  down to the right as I went to M81 this would be on the top right edge of the picture and M82 would not have even been in the picture. On my EQ3-2 mount i had I found M81 and M82 in same FOV with 18mm after Nick showed me were I was going wrong.

 

[cjdawson]

Just one curve ball to through into this.

How are you powering the mount?

Battery if so, what kind?   Mains adapter, if so what brand model etc?

 

Reason that I'm asking is that scopes can be a bit tempremental.  If you are powering from a mains supply of some kind, it might be that you are getting a dirty DC voltage - there could be a little ripple going on that is knocking the timing of the mount out.

At the same time, there is also a chance that the voltage could be incorrect - only by  acouple of volts "under load" which again could be causing the mount to drive at the wrong speed.  i.e. knocking the timing out a bit.

If it's a battery, what type of battery are we talking about? and how big?  This can also have an effect.  For batteries in the UK for astronomy use, you might as well halve the number of Ah printed on the battery casing.  For lead acid batteries, they're measured when operating at 25°C and in this country you need to drop I think it's 1% for each degree of temperature.  So, if we are out on a cold night...  say 0°C, that's 25% of the battery lost due to temperature alone.  That's before we start talking about voltage drop on cables, age of battery and other things.

[wookie1965]

I have not got a battery yet I will do in future I will ask which is best when i decide I was going to get one of these (http://www.ebay.co.uk/itm/320645098035?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

I use this power supply now http://www.ebay.co.uk/itm/12V-DC-5A-CCTV-Cameras-POWER-PSU-ADAPTER-2-1mm-4-WAY-SPLITTER-UK-3pin-Power-Cord-/400569415133?hash=item5d43cc35dd:g:JHwAAOSw4HVWDFcL

I hope it is right otherwise have to get a new one don't know which.

 

 Paul

 

[cjdawson]

On paper your psu looks ok.

Have you tested the output voltage with a volt meter?   If so what voltage are you getting?    As a test compare the voltage against your car's battery (when everything is turned off)

 

Car batteries, and leisure batteries give about 12.6 volts when they are fully charged.  And it drops as the battery drains.  So somewhere between about 11v and 13v should be fine.

However, what's not so easy to measure is any ripple in the voltage.   With a digital voltmeter you should get a reading that is stable.   But you may have a rippling effect going on at high frequency.

To see it, you'd have to use an oscilloscope to view the wave form.   If it's a great power supply, it will be perfectly level.  If it's a good one, you should get only the tiniest of drops between each wave (and I mean tiny)   if it's bad, what you'll see will look like a series of round arches. 

 

I used to power my telescope from a jump starter, much as you are suggesting.   It works great when the battery was fully charged, and would last the night - if I was only powering the scope mount from it.

Over time, I switched up and have been using a 85Ah leisure battery instead.  Much much more power (I think of it as a 40Ah battery - as in 40Ah of useable energy) and have been able to run my scope, dew heaters skifi, cameras and laptop from it.

In real terms, with everything turned on in normal operation I tend to pull less than 3 amps, so i get about 12.5 hours use before I even start thinking about whether the battery is likely to go flat.

[wookie1965]

Thankyou I will check the voltage and now I know what batteries to get. As I haven't got access to an oscilloscope so cannot check the wave pattern. Thankyou for the information really appreciate it.

Paul  

[wookie1965]

voltage checked 12.38v no fluctuations so without oscilloscope i cannot tell about waves but it seems ok.

Paul