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celestron cg-5 question

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#1 donnie3

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Posted 12 August 2009 - 08:57 PM

i have the cg5 with dual drive. a real fine mount for the price. i like it so much that im thinking about buying the computer goto type.i head a lot of people on this forum complaining about the noise it makes when the motors are running. is it as bad as some people say, is there something that you can compare it to, is it loud enough to wake someone up in the house next to you. thanks, don

#2 Tom Andrews

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Posted 12 August 2009 - 09:12 PM

Don,

I'm one who recently was looking for a way to muffle mine. My situation is unique in that my wife and I live and travel in a motorhome and stay in RV parks. RV spaces can be as close as 10' apart and RV's have 2" walls at best. Most parks have a 10:00 PM quiet time. The CG-5 is going to be a problem after 10:00 PM for me.

Right now we are staying in my folks backyard and I've been experimenting. With nothing running in the house (air conditioner, TV, etc.) I can hear the CG-5 slewing from the back bedroom (closest to backyard where I'm set up) and that's with doors/windows shut. If anything is on in the house, it can't be heard. The distance was approximately 35'-40'. (EDIT: I just measured this distance and it was 50'.) This is a standard house with 2x4 walls, stucco outside, sheetrock inside. So when people are sleeping or trying to and they are in a bedroom closest to where you're set up, they may beable to hear it. But it's doubtful that the next door neighbor will unless you're setup very close to their property. But if they have a window open, that could be a problem.

#3 ibase

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Posted 12 August 2009 - 10:04 PM

Don, listen to the actual CG-5 "noise" in this YouTube video about an owner complaining about the sound from his mount:

The funny noise from my Celestron CG-5 mount

For me it's not noise, it's music to my ears. :)

Best,

#4 Tom Andrews

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Posted 12 August 2009 - 11:10 PM

Don, listen to the actual CG-5 "noise" in this YouTube video about an owner complaining about the sound from his mount:

The funny noise from my Celestron CG-5 mount

For me it's not noise, it's music to my ears. :)

Best,


That's a good idea of the noise, however, he was making that video for a specific problem he had. There are two things missing from that example:

1.) It's the DEC motor only running (which is the loudest of the two) and not both running at the same time which is louder.

2.) There's no weight on it. Once you add the OTA and counterweights, it gets even louder.

Let me just add here that some good ideas came out of my thread about muffling the noise:

1.) When viewing at a time/place that might disturb others, start at one place and work your way around the sky by constellations and/or quadrants. This keeps the slewing to a minimum instead of hopping all over the sky. I did this the last two nights I was out and it worked very well.

2.) Manually slew at a slower (more quiet) rate to the area of sky you want to observe something then do a goto which means it won't slew at high speed very far.

Everything else about this mount is excellent. It does goto's very well and it tracks perfectly for a long time. I've only used an inexpensive Meade goto scope, a 5SE, a 6SE and an 8SE. Compared to those, my CG-5 is a dream for goto's and tracking. I can only imagine how nice the other more expensive mounts would work, but for the price this mount is a very good deal.

#5 donnie3

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Posted 13 August 2009 - 01:56 AM

thanks guys for the replies, i played that video on you tube, man!!! that thing is noisy.wonder if all the goto mounts are like that. do

#6 Luigi

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Posted 13 August 2009 - 06:05 AM

It's only noisy when slewing at top speed, which is the only speed it slews at when go-toing an objecting. Slewing with the controller by hand at rates below top speed is much quieter. A workaround is to slew close to the desired object by hand at a slower slew rate then use the go-to to finish the job.

#7 pogobbler

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Posted 19 August 2009 - 02:56 AM

I have one of these mounts myself and I can't recall for sure, but isn't there a way you can limit the speed of the slewing to keep it quieter? It means it takes longer, of course, but it would be quieter.

#8 Luigi

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Posted 19 August 2009 - 06:30 AM

>>>isn't there a way you can limit the speed of the slewing?<<<

Only for manual slews. Go-to slews are are full speed only.

#9 Patrick

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Posted 22 August 2009 - 07:41 AM

thanks guys for the replies, i played that video on you tube, man!!! that thing is noisy.



It's not sensible to make any kind of judgment about how loud a CG5 is based on that video! How close was the microphone to the mount? How loud was the gain? How loud is the volume set on your speakers?

I was out using my CG5 last night and thought about this noise issue and wondered if the neighbors sitting on their deck could hear my mount. On the other hand, they were making so much noise themselves, they probably didn't even notice it. It's a little over dramatized, IMO, although I can understand Tom's concerns in the trailer park situation.

Patrick

#10 Ian Robinson

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Posted 22 August 2009 - 07:50 AM

Have you looked at the Vixen GPD2 Starbook Upgrade kit ?

I believe the CG5 d/axis non-Goto version (I have one too) has the same gearing as the GPD2 ie 144:1 on the RA and Dec so this should be an easy upgrade to do (with minimum seating mods to the upgrade kit to accomodate the servomotors).






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