Red dot finder.

[Highflight]

Hi All.

Can someone tell me how to set up the red dot finder on my 8" LX90 gps please. I have it connected up ok and it works but the actual housing of the finder is so flimsy and loose that I can't understand how it could possibly do anything. Obviously I'm doing something wrong but don't know what. Could someone explain from scratch how it is set up and used please. Would be most grateful.

Thanks.

Chris.

[Talitha]

Hi Chris, i've got an LX-10 (your scope's little brother ).

I've also got a red-dot... hope this helps.

First off, every re-dot i've ever had has needed some sort of altitude shim because the screw which controls the N/S movement just doesn't seem to go high enough. I attach them to the OTA with double-stick tape though.. that might have a lot to do with it.

That being said, yes, they're a bit flimsy and loose (good description, btw!). I've found that i need to re-adjust the finder at the beginning of every session. If you find things going wonky, just give the finder a touch-up during the session. Despite their faults, the red dot finders have always made it a lot easier for me to get into the ballpark than a regular finder scope ever did.

I guess it's a love/hate relationship.

[yeti monster]

Once I got mine set it seems to have remained close as makes no odds acurate, and that despite several wee knocks going in and oot the hoose. I must say though, that mine doesn't have that much of a "flimsy" air about it, must have been made when quality wasn't such an extra value.

[Highflight]

Hi Carol and Yeti Monster. Thanks for the help. The only reason I can see for using my RDF is so that the GPS will work, but if it's not lined up properly how can the GPS get an accurate reading? Having said that, Autostar has always found the 2 alignment stars first time regardless of the RDF setting. I don't understand that. Everything that the instruction manual say's, is so contradictive of what it actually does. I'm really confused with this. I'm getting the impression that the RDF is just an antenna for the GPS and the 'hump' in the fork is just a receiver. I'll find out one day. lol.

Thanks for your help Guys.

Chris.

[peeceeTal2M]

Hi Chris, the only time you'll need to use the RDF is if you are finding objects manually without the autostar, it doesnt have any connection with the GPS and its not needed for the GPS to work. Its for when you chose to star hop to find objects, works like a gunsight

[Highflight]

Thanks Peecee. That's almost explained it, but, in that case, Why won't Autostar work when the RDF is disconnected? This is why I thought the RDF is some kind of antenna for the GPS. Without the RDF, the scope can only be set up manually, but with RDF it will 'auto-align'. This is what's confusing me most.

Chris.

[Capricorn]

Read this last night and didn't understand it then and understand it even less now.

My question is what do you do when the RDF is attached?

Also what is it that you believe that the gps function does? As in what data do you believe does the gps determine and feed to the scope?

All I can think of is that in one instance with the RDF you are doing something that you think the GPS does but that it isn't. Hence a piece of information is missing for the scope when the RDF is not present.

I would GUESS that the GPS determines:

Lat+Long.

Possibly the direction that the scope is pointed. As in it works out where north is.

I do not think that the GPS will know if the scope base is level and therefore probably not if the tube is level. The system may be able to determine one.

If the base is not level but the tube is then as the scope slews the plane in which it slews is not horizontal. In this case the first alignment star will not be observable.

This assumes that the scope at the start of alignemnt does not first point north and gets levelled then performs a rotation of the tube by 90 deg and from this determines the base plane angle. If it does this then it is possible to determine the error that has to be taken into account. This would need sensors to determine level and I have no idea if such is present.

A disclaimer here is that I do not have one and all this is guesswork. The other point is that the RDF will not help level either scope base nor tube.:icon_scratch:

[Talitha]

Wow, looks like i totally misunderstood the question. Sorry, Chris. My scopes are all manual and i wasn't aware that the RDF could actually be connected to a scope's GPS.

No wonder people say i'm technologically impaired.

[Highflight]

Carol, the RDF isn't attached to the GPS, it's attached to Autostar and Autostar uses GPS to find and align it's self, also to find North and to level it's self, (somehow). It's totally confused me too. lol.

Capricorn, When the RDF is not attached, the scope has to be manually set up using star charts etc, or, can also be manually set up using the Autostar hand unit. This requires manually levelling the scope using one of those spirit level bubbles, then entering the exact GPS location of the scope, followed by determining North using a compass, followed by lining up 3 stars. However, when the RDF is attached, simply push a button on the hand box and wait for it to finnish, but what confuses me the most is that the RDF only has to be switched on to do this. HOW THE HELL DOES IT KNOW WHAT IT'S LOOKING AT IF IT'S NOT ALIGNED WITH ANYTHING? but somehow, it seems to set it's self up no problem.

I don't understand this myself, either. lol.

I hope it's now as clear as pea soup instead of mud. Probably not. lol.

Chris.

[Talitha]

Carol, the RDF isn't attached to the GPS, it's attached to Autostar and Autostar uses GPS to find and align it's self, also to find North and to level it's self, (somehow). It's totally confused me too. lol.

Chris.

All of that tech stuff flies over my head like the Shuttle... i hope you find the answers you're looking for.

[PeterW]

I assumed the sensors for the Autostar (GPS +compass+level sensor) were contained in a little block attached to the scope somewhere (on top for the GPS). Without it connected the scope won't know where it is and will then need to be 'shown' where the alignment stars are as you mentioned.

A red dot finder is a little manual thing with a round lens you look through (google for images) and it projects a dot on the sky... no wires or attachments to anything. Usually is attached to a firmly attached adapter 'shoe'.

If you could post an image of the finder you have the query about it would be most useful.

PEterW

[peeceeTal2M]

Hi Chris your rdf should not be attached to the autostar handset!!!!! According to the instructions i've downloaded it attaches to the telescope OTA, to the left of where the finderscope fits!! You then need to align the scope first then align the rdf(smartfinder) using the autostar handset. The photo on page 6 of the instructions show where it should fit. If you need a copy pm me your email and i'll send them to you as file is too big to post here. Hope this sorts out your problems.

[Highflight]

Peter and PeeCee, the RDF is placed on the OTA as it should be, but, if you look at the picture, underneath the RDF you can just see a coiled cable. This cable plugs into the right hand fork next to the power input plug/socket. If this cable is plugged in, no problem, Autostar will self align the scope, easy, but, if this cable is not plugged in, I have to go through the rigmorole of manual alignment. The question that I'm trying to find the answer to is, If the RDF has nothing to do with Autostar, why does it have to be connected for Autostar to work?

The RDF is so loose and flimsy, sat on my OTA, I can't possibly see what it can do for Autostar. With the adjustment screws set correctly, (RDF aligned correctly), the RDF unit is as loose as can be, and can be moved just by a gentle breeze. I would much rather use the viewfinder as this is correctly lined up and is as solid as a house. Hope this helps a bit. I'm totally confused, so I'm sure everyone else is. lol.

Chris.

[Nick R]

Hi All.

Can someone tell me how to set up the red dot finder on my 8" LX90 gps please. I have it connected up ok and it works but the actual housing of the finder is so flimsy and loose that I can't understand how it could possibly do anything. Obviously I'm doing something wrong but don't know what. Could someone explain from scratch how it is set up and used please. Would be most grateful.

Thanks.

Chris.

Mine was the same on my etx , not sure if its the same type ,Are you finding that it does not go high enough when trying to line the red dot on a terrestrial image after lineing up the scope to the image ,If that makes sense or is it just the fact that it is not attached to the scope by the strongest of mounts

[Highflight]

Mine was the same on my etx , not sure if its the same type ,Are you finding that it does not go high enough when trying to line the red dot on a terrestrial image after lineing up the scope to the image ,If that makes sense or is it just the fact that it is not attached to the scope by the strongest of mounts

Hi Nick.

Yes, your ETX has an identicle RDF to my LX90, and both of those come into it. It only goes so high and then runs out of adjustment, and also, although the shoe holds it firmly, the actual housing is so loose it can be moved by the slightest breeze. But that's not the actual issue. I have just tried a little experiment. Now, let's see if anyone can answer this one. With the RDF cable plugged in, but, the actual RDF housing is in my trouser pocket, Autostar aligns the scope perfectly. Now how can that be? What has the RDF got to do with Autostar, and why does it have to be plugged in to make Autostar align the scope. I've just proved to myself that the RDF does nothing to aid Autostar, but is required to make Autostar work correctly. I'm totally baffled. What I'm trying to say is, I'd like to dispose of the RDF altogether, it's so inacurate, but Autostar won't set up without it. WHY?

Sorry to be a pain, but this is really bugging me.

Chris.

[peeceeTal2M]

I'm guessing that once the rdf is set up if you look through it and center it on an object the autostar handset will identify the object for you? i seem to remember my lxd55 could do something like that. As this rdf is part of the setup the software must need to recognise its there and working, even if not aligned, for the autostar to work correctly. Have you tried asking on a lx90gps forum if there is one

[Nick R]

I had the problems with it not hold and lack of adjustment so i returned the scope which they exchanged , the newer scope does not have these problems , how old is the scope ? have you tried where it was purchased from for a answer.

you may find the answer on here

http://meade4m.com/forum/index.php/board,4.0.html

[Highflight]

Thanks PC. It's possible, although it's never done that before, but worth remembering.

Nick. Thanks for the link. I had forgotten all about that forum. I registered 18 months ago when I bought it and never looked at it since. What a plonker. I'll give it a try.

Big thanks to all, and I'll try and post the answer on here. (if anyone knows, that is. lol.).

Chris.

[Highflight]

I DO NOT BELIEVE THIS!!!!

I logged onto the Meade Forum and, low and behold, the 4th question down is the exact same question that i've been asking on here. Why does Autostar require the RDF to be initiated to make Auto Align work?

The answer:

Easy. The RDF contains a small circuit which Autostar uses to determine the level and direction of the OTA. This is known as Level North Technology. Without this device connected to Autostar, neither automatic levelling, nor 'auto north' is possible. Autostar will revert to 'Easy align' if the RDF/LNT unit is not connected to the Autostar power terminal in the mount forks of your LX90 GPS.

*%$£&^ HELL.

Well, of course, I knew this all all along.

[Nick R]

I knew that ! i just read it on the forum lol:D:computer: I was going to pm you the link but you beat me to it

[Highflight]

A very big THANKS to all who tried to help with this. I'm not usually this stupid, I should have remembered the Meade site. Totally forgot about it, and the answer was right there on the first page. I can relax now, and once again my thanks to all. Sorry to be so confusing.

Now, let's see if I can glue this RDF back together.........

[Highflight]

I knew that ! i just read it on the forum lol:D:computer: I was going to pm you the link but you beat me to it

:hiding:Thanks Nick. Thank Heavens for that. It's been bugging me for ages. Thanks for the link.

Chris.

[PeterW]

....might as well hack the 'Red Dot' bit off the top, so it doesn't catch the breeze so badly.

PEterW

[Talitha]

A very big THANKS to all who tried to help with this.

All's well that ends well.