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Saw toothing with PHD2

Phillyo

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libraryman

libraryman

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Interesting. That last trace clearly shows that PHD2 did not issue any guiding corrections when DEC first throws a wobbly, then recovers a short while later.

Could this be a USB or cable problem? Are you using a USB hub? How long are your USB cables? Do you only have guiding issues when you are imaging?

Good observation!! however RA is still issuing correction at that time...

Ray

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Phillyo

Phillyo

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I can try using PHD rather than 2? I have just installed the newest version of PHD2 to see if that made any difference but it didn't. I also have a new cable coming today (hopefully) as I thought this might've been an issue. I do use a hub, so I shall try connecting straight to the laptop to see if that solves any issues too.

I'm willing to rule everything out before sending the mount back!

Thanks all,

Phil.

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strutsinaction

strutsinaction

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I'd try connecting the Lodestar directly to the laptop rather than through the USB hub. I'd also leave your imaging camera disconnected. Calibrate as usual with PHD2, then slew elsewhere and begin guiding and see what happens. If that doesn't make any difference then as a last resort try PHD but to be honest I don't think that will help.

What spec laptop do you have?

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Phillyo

Phillyo

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Laptop is a good spec, i5, plenty of RAM etc.

What I can't understand is why the DEC suddenly just goes so far out? There wasn't much wind last night, plus the scope is so small it doesn't catch much wind anyway. It's tracking in DEC nicely for a long time then BAM a huge jump. It's almost as if there's a bit of grit or something in the gears, except the Avalon doesn't have gears, it's just a pully system.

Interesting is an understatement! :)

Phil

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strutsinaction

strutsinaction

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And just to confirm, your tripod is on a solid surface not turf, all tripod bolts are tight, and you are not prone to jumping up and down every few minutes, and you're not next to a train line, etc? Just trying to eliminate some other causes here  :smiley:

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Phillyo

Phillyo

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The tripod is on grass in my garden but it's resting on some mount rests to spread weight etc. No train lines and I'm usually sat in my lounge with a 20m USB cable out the window to the hub. :)

I've been known to jump around the last few weeks in frustration yes, but that's normally whilst shouting at my laptop in my house :p

Phil

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ollypenrice

ollypenrice

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I don't like hubs and don't use any. I like separate USBs and as short as I can get away with. Primitive man! (The very day I was told to get a Hi Tec Astro box to simplify my cables I saw a recall for the product on the FLO section. Yes, well.... that's why I like my separate cables!)

I must say that my one foray into PHD2 produced nothing but nonsense and mad behaviour so I've never been back to it. The original PHD worked well enough for me though. But out of long habit I guide in AstroArt 5. It is insanely busy to set up, has a crazy number of open windows, but it works and I know how to tune it.

Olly

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Phillyo

Phillyo

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It has a repeater so I don't think that's the issue, plus it worked fine with the EQ6? However I'll check that at the same time as checking the USB hub by plugging straight into the laptop :)

Cloudy tonight so it'll have to wait though :(

Phil

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ollypenrice

ollypenrice

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It has a repeater so I don't think that's the issue, plus it worked fine with the EQ6? However I'll check that at the same time as checking the USB hub by plugging straight into the laptop :)

Cloudy tonight so it'll have to wait though :(

Phil

Wouldn't yu be better to keep the observatory end self contained and then use Team Viewer to operate it from the house? I think boosters are asking for trouble.

Olly

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Phillyo

Phillyo

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If only I had an observatory Olly! :) I set up each night in the garden then sit in my lounge to control things...because it's cold outside and I don't like getting cold fingers :)

However I agree with what you're saying so next time I'm out I'm going to plug everything I can into the laptop and stay outside for a bit with a hot coffee to see if it makes any difference to the guiding.

Maybe I can "pop down" to your place and leave my equipment there to take advantage of your obsy and dark skies Olly :p

Phil

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wuthton

wuthton

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I use a long network cable from a homeplug to the mount pc and remote desktop from the house.

I've had nothing but trouble from hubs in the past but I'd be as surprised as you if it turned out to be the root of your problems.

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Phillyo

Phillyo

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Well, update.

I accurately aligned this evening then plugged everything except the Focus control and my QSI directly into my laptop (they are through the USB Hub still). I've just taken my first 30min sub aaaaaaannnnnnnnndddd....everything is fine!! FOR NOW! I'm going to leave it going whilst having my tea and watching a film, then i'll check the trace and the images but fingers crossed that's solved the issue?? I hope so. If it's as simple a fix as a usb hub then I'll be happy and I'm sure Luciano from Avalon will be happy too!! He was ready to send me a new mount out, no questions asked!

Lets hope it keeps going well.

It's jumping about a small amount this evening but that's due to the gusting winds I think. I'll update with some pictures of the subs and the stars (which is the important thing) tomorrow hopefully.

Thank you EVERYONE for all your help and suggestions on this. Even if this isn't the cause I really appreciate everyone taking the time out to help me.

Phil

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Tommohawk

Tommohawk

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Fingers crossed, but sounds good!

BTW I was imaging Lovejoy with PHD2 the other night - bit of an experiment TBH - and struggling with guiding due to cloud. Looking at the graph one thing I noticed is that, similar to your posted graph, the Dec could wander off quite a bit before commands were sent to correct. Not sure what this means, but thought I'd post just for info.

(By the time I got guiding sorted Lovejoy diappeared behind a hedge... and I ended up with some very badly focussed botanical images.)

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strutsinaction

strutsinaction

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Hi Phil

Sorry to hear your guiding issues are still not resolved.

Just out of interest, what Declination Algorithm have you got selected in PHD2? Hysteresis or Resist Switch (the default)? I think Hysteresis is recommended for non-backlash mounts like the Avalon. Might be worth a shot if you have Resist Switch currently selected.

Regards

John

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