HEQ5 go slow!

[dph1nm]

My trusty GOTO-upgraded HEQ5, which I have had for several years without any problem, has helpfully decided to start tracking too slowly in RA. Below is a sum of 18 mins worth of 45sec exposures (on M108 as it happens), with no attempt to align them, colour coded in ~4min blocks, white - blue-green-red in time order. RA runs roughly horizontally across the image. The pixels are ~0.9" , which means I have trailing of about 400" in 18 mins (in the sense that the mount is tracking too slowly)!

Anyone got any bright ideas how an HEQ5 can do this? The PE on the mount is only 40" peak to peak with a 10min cycle (I measured it last year). It has only been misbehaving like this since Christmas. This was taken at about 55deg dec by the way - it gets even worse if you head down towards the equator.

NigelM

[martin_h]

Is the tracking rate set correctly on the handset?

[Astro_Baby]

Whats power like ? Is it good, reliable etc,

Whats the power lead like ? If its the bit of damp string that comes with the mount it may be a problem in the cold.

[dph1nm]

Whats the power lead like ? If its the bit of damp string that comes with the mount it may be a problem in the cold.

True - I do use the original power cable to connect to the mount (power comes from the mains).

Is the tracking rate set correctly on the handset?

I wondered about this so I tried re-setting it to "Sidereal", but it didn't make any difference.

The curious thing is that it is so smooth - it appears to mis-track at a constant rate (I have tried 15 sec exposures and they still show trailing). I guess its time to open up the box and check the gears haven't come lose!

NigelM

[Peter Drew]

At what rate does the HEQ5 worm turn? If it's 1 rev in 4 minutes there might be a worm/wormwheel adjustment issue.

[dph1nm]

At what rate does the HEQ5 worm turn? If it's 1 rev in 4 minutes there might be a worm/wormwheel adjustment issue.

I think the PE on these mounts has a period of 10mins.

NigelM