A new mount and a question

[Steffen]

Today I did what I had in mind for a long time and got myself an HEQ5 Pro mount for my 6" Maksutov. I bought it purely for visual use, expecting it to track objects for me even with poor polar alignment. This should ease observations at higher mags and star testing, where the need to constantly pull the scope along can become a chore. I would be lying if I said I didn't also look forward to some goto action, for when things are hard to find (suburban light pollution) or just to give friends and family a tour of the sky and its gems.

I gave the mount a spin tonight from my backyard and found the set up procedure to be fast and uncomplicated, and the weights involved easily manageable. The SynScan controller has a few usability quirks but is simple to operate and figure out. I'm impressed with the goto accuracy after a quick and dirty tripod alignment with bubble and compass and a 3-star alignment using the SynScan. The mount successfully put all objects I tried into the field of a 7.5mm Tak at 240x. I did not expect that. If that's how things turn out to be I'm very happy.

My first hour with the SynScan was spoiled by random failures and freezes, which I tracked down to the hand controller cable. Everything worked fine with a Cat-5 ethernet cable I used for comparison, so I took a closer look at the RJ45 connectors and found that they hadn't been crimped all the way. After fixing this everything worked flawlessly.

Mechanically, the mount makes a reasonably good impression. It is tight and smooth and feels very much in control with the Maksutov (MK-67) on top. The gears make occasional screeching sounds at certain revs when slewing fast, but I had heard this before during observing night and am not too worried about it. The tripod-mount-scope combo doesn't dampen vibrations as fast as the Williams EazyTouch with walnut tripod, it takes at least twice as long (about 3-4 seconds). I didn't put much effort into stiffening the rig, so there may be room for improvement.

Finally a question. I've powered the mount from a Celestron PowerTank 17 tonight which didn't last very long. After three hours or so the power LED started blinking to indicate low supply voltage. Based on specs and advice from Luke at Andrewscom the mount should last all night on a PowerTank 17. Is this normal? What are others using to power their HEQ5 Pros?

Cheers
Steffen

[Tandum]

I used to run mine off an old car battery with a charger across it and a 6 meter lead running out to the mount. It used to blink whenever it was slewing but always worked ok. I guess it's just a low volts indicator. I found pointing came apart when you slewed across the meridian. ie: flip and find :)

[Scorpius51]

Hi Steffen

I run my HEQ5 Pro off a 12 volt, 7 amp-hour, sealed battery from Jaycar. From a full charge they would go for about 5-6 hours I think - depending on how much slewing is done and the balance. I have 2 - one is a spare to plug in when the first starts to blink. I had similar problems with my cables, too. But, all in all, a great mount.

Cheers
John

[Steffen]

Thanks for the replies. I might try running the mount straight of a battery, too. I was told not to do that and use a regulated supply instead because the mount is sensitive to voltage spikes etc. However, the PowerTank doesn't seem to regulate very well, it starts at 12V with a full battery and drops to about 9V before the mount gives up. A battery by itself would start at around 14V and not drop much below 11V…

Cheers
Steffen.

[DRCORTEX]

If your using it from home ( or close to a 240V outlet ), you could use an AC/DC converter. Got one from Andrews for around $40 with every connection you would need for a 12V device.

Cheers
DOC

[mithrandir]

When I'm at home I float my powertank off a 20A lab supply. When I'm away I float it across the 2nd battery in the Prado. That means it is just acting as a large capacitor.

It will power my G11 for a few hours on its own as long as it is not running anything else.