Hi there,
yesterday we had a clear sky and I tried to guide for the first time. I dont know if my setup is going to work that way.
Maybe someone has same setup and can help me to find the error.
The guide cam is an analog Watec902H (without guiding port) inserted in a Skywatcher 9x50 Viewfinder.

My setup is:
Mount: EQ5 SynScan Kit (set to PC-Direct Mode)-->Handcontroler-->Serial/USB-->/dev/ttyUSB0
Guide cam: Watec902H-->Mod'ed Skywather Viewfinder -->stk1160Grabber-->/dev/video0
I set guiding cam prperties to: Focal length: 700, Aperture:50

I set the mount to track, choose the guide star and start calibration. Beside the normal tracking noise of the motors I can hear
that ekos changes the motor speed but most of the time I get the error "guide star drift to short" or so, I played with the Pulse value too but no success.
And sometimes I get the error below in the picture and in 1 of 10 retries it went through the calibration. In the second picture
the drift graphics shows there is something wrong. The green line goes down until the guide stops automaticaly.





So maybe someone has an idea whats going wrong.

Maybe EQMod guide rate is too low? It is set to 0.3 try increasing it. I never guided with EQMod before, I will try it today and see which settings work best.

Yes I will try guide rate if sky clears up again. Well I can say that at least Alignment works great with the same setup and default guide rate at 0.3.
I found maybe one more error. The Viewfinder attached to the cam is not 700mm but 170mm in focal length, dont know how this might have influenced any calculations.

FYI, I tried calibration and guiding with EQMod directly and it works flawlessly without any changes to the EQMOD driver. Trying using "High contrast" instead of autostretch as it might be less noisy.

Ok, thank you. I will try it again. Still no clear sky.

I can confirm increasing the guide rate to 0.5 helped. Calibration works without errors. Drift graphics jumps around 5" and doesn't get better after 30 seconds but I think that's because some more fine tune and better seeing is needed. Clowds stopped me now again.

[slightly offtopic]
I just read somewhere that the guide scope F should be at leat 1/3 of the teleskope F. My skywatcher is F=1000mm. My guidescope is only 50mm. That could explain the errors. I will put a 2x barlow into it to incease its F to at least F=100mm.

[edit] Again I totaly messed up with values! My guide scope is NOT F=50mm but its APERTURE=50mm. Its F=180mm doubled by the barlow should give F=360mm

Question: What are typically good values for the Y-scale in the drift values? I read normal seeing in not so good places might limit the resolution to about 4 arcseconds. Very good observatories have about 1 arcsecond without the use of adaptive optics. Are those values the same as Sig(RA)"/Sig(DEC)" ?

Now I replaced my guidescope with my 300mm Tamron Lens on an 2x teleconverter for 600mm focal length. I can now calibrate with 0.3 guide rate without errors. Sig(RA)"/Sig(DEC)" values decreased from ~5" to <=3", but still quite unstable but I guess this is due heavy seeing.

I found that proper polar alignment makes a huge difference in the guiding performance. So make sure you are properly aligned as well! On my HEQ5, It is always below 2 and most at the time below 1. I guided 20x exposures each 10 minutes long in one night. After 3 nights, I got this (in heavily light polluted area nonetheless)

Ok, good to know. Does Ekos show somewhere an predicted polar alignment error after doing an slew to target alignment? I guess there are several sources of error in my setup that multiply to that high error values. Sadly I am currently forced* to do an Polar Alignment by polar scope only because my telescopes field of view is awkward only NW-N-NE. I think this will never give that accuracy which an drift alignment near the south meridian will give. I will try to optimize my polar alignment routine first.

(*current health status and dwell situation)

@knro
How is your HEQ5 setup? Do you use an Synscan Handbox? I've just read that USBtoSERIAL-->HANDOX-->EQ-Mount might be a source of latency/guide error problems. Ive just ordered an USB-TTL232R converter so that I can connect directly to the EQ-Mount Interface and put this Handbox away.