The Great EQ6 goto test!

[KG8]

Well tonight is the night, the seeing is good here in the inner-city and the moon is well phased and well placed for a little observation. But that is not what dragged me out into the back yard tonight. No Sir, tonight is the night when I put my theory about goto run-outs to the test. If you own an EQ6 you may or may not have noticed that after 3 or 4 hours the GOTOs go off and your eyepiece no longer centers back on target, even if you had entered that target in the PAE list. This has been a source of major frustration for me and I have gone to many lengths to find the cause. Last time out I noticed that the HC's internal voltage sensor was displaying the voltage at the mount as being 11.9V early in the night ( with a freshly topped off battery ) and 11.1V later on. Could this be right? The battery is fine, 12.3V at least, well within the 11~15V window the specs say the mount needs. It's the cold I thought, I heated the hand controller. No good! But what if... What if a volt is being consumed in the mount before it gets to the critical circuitry. Then the voltage will really be down around 11 at the mount and perhaps at the lower end of the range things get screwy?

Well tonight I have a 3.5A charger on the battery as I observe and the mount is saying 12.8V internally. Now we wait... and see... And if all goes well and we get no run-outs then it was voltage drop . All I need do then is put a DC-DC inverter between battery and EQ6 and bump the voltage up a volt or 2.

I shall return and report later then, but for now...
it's back to the moon.

[matt]

Interesting stuff.

How does one check the HC internal voltage sensor? Is it possible to bring an internal voltage reading up on the HC screen?

I have the 2.05a version of the HC

[Terry B]

It is in one of the sub menus in version 3.2. It also tells you the temperature although it is the controllers temp not the ambient. I have found that if the controller tells me it is less than 3 deg C then it turns itself off. The ambient temp at the same time as been much lower ~-3 deg. To solve this I periodically heat the hand controller with a hair dryer.

[KG8]

That's the way of it Matt. Your controller isn't missing much though as both the temp and voltage are useless aside from diagnostics you use once I recon.

Interesting that it shut down on you terry, I've had mine out in -2 and it didn't shut down, guess I was just on the brink. You ever had trouble yourself with goto's?

EDIT:
12:15 am
Well the results were unconclusive. goto's went out in RA and DEC after 3 hours, right out of the EP, but I also realised "then" that I had only done a 2 star alignment so I'm blaming it on that... this time. It's not mirror flop because the finder scope is out too. I will post back when I get a positive result.

[acropolite]

The voltage drop could be due to wiring. At 12 volts even small amounts of resistance will cause appreciable voltage drop. If your Eq6 is drawing 2 amps, even 0.5 ohm of resistance in the cable will give 1 volt drop.

[KG8]

I tested the cable phil, it comes in at 0.1 of an ohm if that. I replaced the wimpy one the mount came with with a cablemuch thicker. I'm not the only one with this problem either, 2 other guys out last astro camp had it with their EQ6's too. We all lost goto accuracy at the same time of night, which makes me think it is temperature or temperature related (voltage drop in batteries)

[Terry B]

[quote=KG8;237656]That's the way of it Matt. Your controller isn't missing much though as both the temp and voltage are useless aside from diagnostics you use once I recon.

Interesting that it shut down on you terry, I've had mine out in -2 and it didn't shut down, guess I was just on the brink. You ever had trouble yourself with goto's?

I haven't had problems with the goto but I must admit I don't use it much in a night. I tend to do my 3 star align and then goto an object and image it. I might goto a second object but rarely slew all over the place. Having said that I was imaging M17 aiming to the east last night and had all sorts of problems getting the guiding to work well. I kept getting trailing despite fiddling with the guiding parameters. After it had significantly passed the meridian I used the hand controller to "goto" M17- the same object, hoping it would flip to the other side of the sky. It did this as hoped and the object was in almost the same spot in the eyepiece after the meridian flip. I think this was pretty impressive. The guiding was somewhat better also when aiming west. I'm not sure why.

[ballaratdragons]

I keep good GoTo's all night long. But I use 240v mains.

The V3 hand controller shuts off at cold temps!!!! Geez, glad I've got a 2.5a. If I had a V3 it would never come on with our temps.

[KG8]

keep a sock handy Ken, that is how I am told some kept the V2 controllers warm in the old days. :D

[ballaratdragons]

Even at -5.9 in the control room I have never had a shutdown, or even a glitch. :thumbsup: