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Thanks Chip.? I got the GM8 working quite smoothly. How it actually guides is yet to be seen.??
The G11 in question used an Ovision worm in RA and a stock (ie not high precision) worm in DEC.? So +/- 2 arc sec in DEC was pretty typical, especially in my mountainous environment with relatively poor seeing conditions.? But my set-up was 3.5 arc-sec/pixel.? So I could get away with poor seeing conditions like those shown in the graph of the G11, with very little impact to the final image.
Best,?
Eric
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Back again! I bought a 35AH AGM battery to power my mount. Going to get another battery to power laptop and other things. Does anyone have a recommendation for a good DC-DC boost converter? Trying to supply 15VDC @3A to the mount.?
I also just received my AT65EDQ so I'm just around the corner to taking my first image!?
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this is what I use, inexpensive and effective if you don't mind rolling your own
B
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These worked well for me and have adjustable output voltage:
I also added a DC volt and amp meter to the box, so it shows just how many amps are being drawn during tracking and slewing.
- Michael
On Thu, Jan 4, 2018 at 9:28 AM, bvalente@... [Losmandy_users] <Losmandy_users@...> wrote:
?
this is what I use, inexpensive and effective if you don't mind rolling your own
B
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Brian,
Those are nice, potted and presumably heat sinked, good find (and cheap), for a wet nighttime environment. I'm going to have to rework mine a bit.
Chip
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Brian and Michael,
When you use these, voltage is controlled to go to 15VDC from 12VDC, how do you control the amount of amps that is delivered to the mount? I've read elsewhere that tracking Gemini II will use around 1A or less and when slewing it will use upwards of 3A.?
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Ah...no worries.? You only set the voltage between 12 and 18V.? I now use it at 17V adjusted.? The system consumes the amps it needs to function.??
How many amps?....
I measured the amps my CG11 / Gemini1 and GM8/Gemini1 takes... under 0.5 amp sidereal tracking... and just under 1 amp fast slewing.? On the CG11, I've got a very heavy Meade LX200R 12 inch and its counterweights mounted.? So outputting even 2 amps will be sufficient ...if the supply can keep it reasonably level.??
The key word "level" meaning free from a lot of ripple in voltage (the modern AC/DC supplies use small buck-boost high frequency like 400 kHz to do that...not big AC 60 cycle transformers any more).? So people prefer larger amp rated supplies like 4 amp to 5 amp.? But I still get good results from even 2 amp DC output rated supplies, like the 12V ones used on external hard drives.? ?
Hard also to know how the China made supplies are really "rated" since cheating on specs gets you more profit.? So I'd sguest you use a 3 amp to 5 amp rated AC/DC supply.??
( Now that they are field tested, I'm going to make up some more of my own booster boxes with the volts and amps display.? These are really nice and compact...the DC plug goes in and it will have either Gemini1 4 pin Power cord or Gemini2 power cord out.? Let me know privately if interested....I'll send some pictures ...)
Have fun, Michael?
On Jan 4, 2018 2:35 PM, " taylorwab@... [Losmandy_users]" < Losmandy_users@...> wrote:
?
Brian and Michael,
When you use these, voltage is controlled to go to 15VDC from 12VDC, how do you control the amount of amps that is delivered to the mount? I've read elsewhere that tracking Gemini II will use around 1A or less and when slewing it will use upwards of 3A.?
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Yes ¨C what he said ;) ? Don¡¯t worry about amps, just make sure whatever you are using for up-converting the voltage can handle at least 5 amps ? Thanks ? Brian ? ? Brian Valente Brianvalentephotography.com ?
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Thursday, January 4, 2018 3:26 PM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: Just purchased GM811GHD? ? Ah...no worries.? You only set the voltage between 12 and 18V.? I now use it at 17V adjusted.? The system consumes the amps it needs to function.?? How many amps?.... I measured the amps my CG11 / Gemini1 and GM8/Gemini1 takes... under 0.5 amp sidereal tracking... and just under 1 amp fast slewing.? On the CG11, I've got a very heavy Meade LX200R 12 inch and its counterweights mounted.? So outputting even 2 amps will be sufficient ...if the supply can keep it reasonably level.?? The key word "level" meaning free from a lot of ripple in voltage (the modern AC/DC supplies use small buck-boost high frequency like 400 kHz to do that...not big AC 60 cycle transformers any more).? So people prefer larger amp rated supplies like 4 amp to 5 amp.? But I still get good results from even 2 amp DC output rated supplies, like the 12V ones used on external hard drives.? ? Hard also to know how the China made supplies are really "rated" since cheating on specs gets you more profit.? So I'd sguest you use a 3 amp to 5 amp rated AC/DC supply.?? ( Now that they are field tested, I'm going to make up some more of my own booster boxes with the volts and amps display.? These are really nice and compact...the DC plug goes in and it will have either Gemini1 4 pin Power cord or Gemini2 power cord out.? Let me know privately if interested....I'll send some pictures ...) ? On Jan 4, 2018 2:35 PM, "taylorwab@... [Losmandy_users]" <Losmandy_users@...> wrote: ? Brian and Michael, When you use these, voltage is controlled to go to 15VDC from 12VDC, how do you control the amount of amps that is delivered to the mount? I've read elsewhere that tracking Gemini II will use around 1A or less and when slewing it will use upwards of 3A.?
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You don't control the amps, it's basically electrical current capacity and you need a power supply that can supply at least as much as the mount requires. more amp capacity will not be a problem, less will.
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On 1/4/2018 5:35 PM, taylorwab@... [Losmandy_users] wrote: Brian and Michael,
When you use these, voltage is controlled to go to 15VDC from 12VDC, how do you control the amount of amps that is delivered to the mount? I've read elsewhere that tracking Gemini II will use around 1A or less and when slewing it will use upwards of 3A.
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Fuses..
?
Fuses control the current..
?
Derek
?
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Thursday, January 04, 2018
4:38 PM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re:
Just purchased GM811GHD
?
?
You don't
control the amps, it's basically electrical current capacity
and you need a power supply that can supply at least as much as the
mount requires. more amp capacity will not be a problem, less will.
On 1/4/2018 5:35 PM, taylorwab@... [Losmandy_users] wrote:
>
>
> Brian and Michael,
>
> When you use these, voltage is controlled to go to 15VDC from 12VDC, how
> do you control the amount of amps that is delivered to the mount? I've
> read elsewhere that tracking Gemini II will use around 1A or less and
> when slewing it will use upwards of 3A.
>
>
>
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Hi Taylor, ? Going to add my 2 Cents
on the Vib Damping Feet : When Imaging, you want
everything to be as Rigid and Stable as possible. There should be no
'vibration' to damp... and these feet add a source of compliance =
drift/misalignment ?I see no purpose for damping feet with mounts this heavy and rigid.
My suggestion : just
press the legs into the dirt solidly and go with it. ? I've seen people use vib
feet on grass .. not sure why .. all that does is make a spongy soft mounting =
something you do NOT want for imaging.. ? I used to have 3 iron
pipes ~ 6" long, 2" dia that I would drive into the ground with a
small sledge ?and use?them
as the base points for my tripod. ? Alex
?
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+1 on not using damping feet. When I used them my imaging guiding etc. was noticeably worse and i'm on concrete (my rationale was i'm near a freeway, maybe the truck vibrations? i dunno what i was thinking)
B
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Brian,
For visual use in high pedestrian traffic areas on dark sky nights the losmandy glow in the dark feet are a good idea to avoid tripping and kicking the mount out of NCP alignment. But for imaging maximum contact and direct coupling to the pad or ground is superior. I place my tripod and table on the concrete observation pad but I place my cases/seating on the dirt to decouple my movements from the pad.?
Chip
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i agree about the high traffic part - i just use glow tape around the leg bottoms for that, but then again 99% of the time it's just me
B
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Hi Brian,
But if I used GITD tape instead of a $100 Losmandy custom made GITD pads what will protect my expensive 3" tube legs from getting scratched on the concrete??  JK!
Chip ?
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Chip,
Good suggestions. Another is don't do any imaging if there will be a group of people walking around. I was at Stellafane one year in the field below the Schupmann Refractor and about 20ft away from a guy trying to image and all I heard was him complaining about vibrations from people walking around. Three other guys in earshot in unison said 'your nuts trying to image with everyone walking around'. Had a chuckle when I heard that. :-)
Don
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----- Original Message ----- From: "chiplouie@... [Losmandy_users]" <Losmandy_users@...> To: <Losmandy_users@...> Sent: Friday, February 02, 2018 3:24 PM Subject: [Losmandy_users] Re: Just purchased GM811GHD Brian,
For visual use in high pedestrian traffic areas on dark sky nights the losmandy glow in the dark feet are a good idea to avoid tripping and kicking the mount out of NCP alignment. But for imaging maximum contact and direct coupling to the pad or ground is superior. I place my tripod and table on the concrete observation pad but I place my cases/seating on the dirt to decouple my movements from the pad.
Chip
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Don,
The LAAS property is in a undesirable location in the middle of nowhere and for dark sky nights which are centered around a new moon people are mostly imaging and no body is really on the property except for other nut jobs. The LAAS is well over 800 strong and the club has family night events during the summer months which attract a large number of members and their families. As you can imagine 4 acres can only go so far and there is a lot of bumping into and unauthorized touching and damaged stuff that happens on these nights. Imagine what it would be like if we allowed drugs and alcohol on the site!?
Someday I'm going to get to be in the right place at the right time to go to Stellafane. So far I've missed it 45 times since I've been thinking about it.?
Chip??
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You only have to go half as far to attend the Nebraska Star Party. You can be set up as close to fellow observers as you wish or further away if you like the privacy aspect. This will be its 25th year celebration.
www.nebraskastarparty.org.
Bob R.
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Friday, February 02, 2018 3:00 PM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: Just purchased GM811GHD
Don,
The LAAS property is in a undesirable location in the middle of nowhere and for dark sky nights which are centered around a new moon people are mostly imaging and no body is really on the property except for other nut jobs. The LAAS is well over 800 strong and the club has family night events during the summer months which attract a large number of members and their families. As you can imagine 4 acres can only go so far and there is a lot of bumping into and unauthorized touching and damaged stuff that happens on these nights. Imagine what it would be like if we allowed drugs and alcohol on the site!
Someday I'm going to get to be in the right place at the right time to go to Stellafane. So far I've missed it 45 times since I've been thinking about it.
Chip
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Chip & brian
I bought a string of red led Christmas lights (powered by 2 aaa bats) and added a linear regulator with a cigarette lighter jack.? The linear is set at 2v so the red leds aren't too bright.? So the same batery that powers my mount powers the led and allows the public just enough light to prevent accidents.
Chuck
Sent from my Samsung Galaxy Tab?|PRO
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-------- Original message -------- From: "chiplouie@... [Losmandy_users]" <Losmandy_users@...> Date: 02/02/2018 12:24 PM (GMT-08:00) To: Losmandy_users@... Subject: [Losmandy_users] Re: Just purchased GM811GHD
?
Brian,
For visual use in high pedestrian traffic areas on dark sky nights the losmandy glow in the dark feet are a good idea to avoid tripping and kicking the mount out of NCP alignment. But for imaging maximum contact and direct coupling to the pad or ground is superior. I place my tripod and table on the concrete observation pad but I place my cases/seating on the dirt to decouple my movements from the pad.?
Chip
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I had no clue about the vibration pads. I thought they might help from light breezes or like others said, from nearby traffic. Thanks again for the advice! I will be hopefully be doing a first light soon!
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Eric Chesak
Michael Herman