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#1 GeHe

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Posted 27 May 2013 - 04:47 PM

Hi,
I have a TDM-unit , version 2.2 , in combination with Losmandy G11, FS2, Lodestar, MaximDL.
I got interferrences between TDM and lodestar , when lodestar wants to correct , I got -16 parsec-spikes , therefore, i reduced the autoguider intervall down to 20 sek. and agressivnes down to 1 in both directions.
The spikes makes me nervous.
is it normal , or can i reduce this interferrences with a special parameter set ?
can i reduce the autoguiderintervall down to 60 seconds ?

what is the common way to work in this combination ?

thanks for answers.

#2 GeHe

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Posted 27 May 2013 - 04:57 PM

Am idea is , that the speed of RA is to slow or too quick , that the corrections were very stong , could it be ?

#3 GeHe

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Posted 29 May 2013 - 08:34 AM

no idea ?

#4 D_talley

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Posted 29 May 2013 - 09:54 AM

Not many people here use the TDM so you will not get many responses. I did not use a guider when I ran my TDM so have not had that problem.

#5 Astronewb

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Posted 29 May 2013 - 02:23 PM

Hello Gerhard,

On the TDM website > http://www.mda-teles...w=article&am... < there is information that might help you with your question. In addition, there is a TDM group on Yahoo groups that Attila monitors and quickly responds to questions.

On my version 2.5 TDM/iEQ45, I use autoguider exposures of 2 seconds and up, to prevent conflicts with the TDM updates in RA. In PHD, I use a RA aggressiveness setting of only 20, so that the TDM does almost all the corrections, and corrections in DEC are handled by PHD.

Here is a PecPrep graph using those settings:

Posted Image
PecPrepRA_032613_iEQ45wTDM by Astronewb2011, on Flickr

Hope the info helps, good luck

Paul

#6 GeHe

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Posted 09 June 2013 - 03:24 AM

Hi Paul ,

Thanks , meanwhile, I got informations from Attila direct , the spikes on TDM monitor does´nt matter.

Thanks

Gerhard

#7 Astronewb

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Posted 09 June 2013 - 10:28 AM

Okay Gehard, very good information to know, and straight from the developer....:)

Cheers,

Paul

#8 orlyandico

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Posted 09 June 2013 - 09:05 PM

Here's my interpretation..

Heidenhain only guarantees an accuracy of 12.96" for that particular encoder. So any deviations less than this is probably more imaginary than real.

I'm sure the TDM is doing some form of Kalman filtering (or similar) to improve the accuracy. Such a scheme requires that there will be spikes and jumps that go uncorrected.

That is, unless the TDM folks have found a way to suspend the laws of physics...






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