PHD Guiding help

[Kevdan]

Hi all,

when using PHD I lock onto a star and then hit the button to start tracking, however after about 6-7 mins of watching the star move slightly i get a box saying star hasnt moved enough. whats the problem? i thought it wasnt meant to move.

Kev.

[Jessun]

Did you click the buttons left to right, camera, mount, loop, PHD? The last button on startup each session allows the program to calibrate and it tries to move the mount east, west, south, north. If you get the message that the star didn't move enough that means calibration failed and there is no - or bad - signal between the laptop and mount.

Rattle the cables, and try to move the mount manually via PHD and listen for movement. The motors will chirp when you move in different directions. Check also the guider setting in the handset - like the guide rate. Something like 50% should be a good start.

[Kevdan]

Did you click the buttons left to right, camera, mount, loop, PHD? The last button on startup each session allows the program to calibrate and it tries to move the mount east, west, south, north. If you get the message that the star didn't move enough that means calibration failed and there is no - or bad - signal between the laptop and mount.

Rattle the cables, and try to move the mount manually via PHD and listen for movement. The motors will chirp when you move in different directions. Check also the guider setting in the handset - like the guide rate. Something like 50% should be a good start.

Thanks,

Yes went from left to right, finally hitting the PHD button, and it doesnt always happen, I know that my mount is an neq6 buteven they need tracking software there's no way I could have polar aligned it so accuratly that it doesnt need adjustment.

I am not using the handset im using cartes de ceil direct through EQDIR/ascom and it is set at sidereal rate.

Kev.

[Jessun]

No matter how accurate your PA is PHD will force the mount to move around around the guide star to get a feel for the orientation of the camera and mount and guiding rate set, so calibration should look pretty much the same every time. It will count calibration steps and display that down the bottom while it goes through this routine.

I have used EQMod too little to advice on how it works alongside PHD, but an army of people use it so I'd expect a few to come in here and put things right.

I'd still check the cable if this is a setup you have used before successfully.

[Stephen]

When you hit the guide button it doesn't actually start to guide. First of all it has to calibrate.

During this process, it deliberately moves the mount, to see how much a star moves when it does so.

If the star doesn't move during this process, then it can't calibrate, and you get the error mentioned.

First of all you need to ensure that PHD can actually move your mount. Bring up the manual controls and try to move the mount with them.

Next step depends on if you are using ST4 or pulse guiding.

If ST4, you need to change the PHD setting (click the brain) relating to how much or for how long it will move the mount. I'm sorry, I don't have a working PC at the moment with my software installed.

If you are using pulse guiding, you need to change the rate at which EQMod will move the mount during guiding, this is in the advanced options, I think you click either a tool or a plus on the small EQMod window.

Sorry I can't be more precicse where the options are!

[Kevdan]

Thanks Again guys,

Im pulse guiding so i'll check the settings in eqmod.

Kev.

[chrisshillito]

When PHD calibrates it issues a series of pulse guide commands so it can determine in how far, and in what direction the mount actually moves. For a give guide scope and camera the amount of pixel movement is goverened by three factors: target declination, pulse duration and guide rate.

The higher the declination the smaller the observed movement so don't expect to find one set of parameters that work for the entire sky.

The calibration pulse duration is one of the PHD parameters available by clicking on the "brain" button, it is called calibraton step. Increasing this will increase the length of the pulse and so the longer the mount will move at the guiding rate - hence more overall movement.

The guide rate sets the speed that the mount moves during a guiding pulse. For EQMOD this can be set from the expanded runtime interface. However, you should really be setting the guiding rate to give you the best performance when actually guiding - not choosing values simply to make PHD'S calibration process quicker.

Initially I would start off with guide rates of 0.5 x Sidereal and increase PHD's calibration step until calibration completes.

Chris.

[Kevdan]

Many Thanks Chris, much apreciated.

Not done much with autoguiding, I have used PHD with my old eq3-2 and a autoguideport adapter but not used it on my NEQ6 due to weather. Last night was first real night out with new scope and mount and it was a massive learning curve, as well as trying to do visual observing I also wanted to take a few pics to see what it could preoduce. Im probably running before I can walk but thats just impatient me.(waited so long for a clear night).

So hopefully from now on its onwards and upwards.

Kev