50 replies to this topic

[StarryEyedSwede]

New member here that is returning to the hobby after a hiatus of some 30+ years. Back in my much younger days I purchased a second-hand Meade 10" SCT LX5 but after a couple of years of fond use life came in the way and I all but forgot about it. Last weekend I dug the scope and all accessories I could find out of storage and tried to reassemble. Here is my initial findings:

• Fork, tripod, wedge - working, though much heavier than I remember
• OTA - only had time for a quick check of the optical performance with my lowest mag eyepiece before the clouds came rolling in. At least the secondary shadow seemed to be centered when I defocused. In focus the stars were almost but not quite point-like though I can't tell for sure since so many things were non-optimal: seeing, location, time for cooldown, no firm surface to place the scope so the view was shaking everytime I moved, etc. I briefly looked into the tube in daylight and saw some dust or residue on the mirrors and corrector but nothing spectacularly bad-looking. Will need to do some more serious testing next time.
• Eyepieces - I think I gave away the 2-3 eyepieces that came with the 2nd hand purchase to a friend, but I got some nice ones (at the time) for various birthday presents. These ones I found and they all looked to be in mint condition.
• Dec motor - working!
• Focus motor - also working!
• Hand controller - Dec, focus, and map light working perfectly, RA not so much. The drive is making sounds, but stars were drifting rapidly across the field in what seemed the "wrong" direction. Flipping the N/S switch had no effect. Note: this was without me pressing any buttons on the hand control. But this didn't seem to be as bad with the 2x setting as with the 8x setting. So maybe the RA input was stuck. Need more investigation.
• Finder scope with illuminated reticle - luckily younger me removed the battery before putting it in storage. But now I have no battery... also plenty of dust inside, need to figure out how to best remove safely.
• A 2" diagonal mirror that I tried attaching to the back of the scope. Good news: in good working condition. Bad news: it is now stuck and I can't remove it again.
• A bunch of accessories I imagine is for photography including a tele extender, some T-shaped thing with a small diagonal mirror, and even an old Canon camera body. Not sure if anything is useful nowadays.

Obviously I am already browsing and searching the forums and the web for info. So much fun, last time I operated this scope there was basically no internet for the masses so any information would need to come from books and magazines. Things have really changed...

 

So, to summarize, some good and some bad. The real decider for whether it should stay unpacked is obviously the condition of the optics. Do you think there could still be life in this old scope? How should I determine this?

 

 

PS. Will rendez-vous with the old scope again next weekend so can take and post some pictures.

[deSitter]

Welcome to assisted astronomy living in the Classics forum!

 

-drl

[DAVIDG]

 I worked on one a long time ago. I think that if you unplug the handcontroller it will still track at the correct rate. If it does then the problem is in hand controller. The one I fixed had a broken wire inside the DIN plug for the hand controller  that plugs into the main panel so that is were I would  look first.

 Clear Line Technology has the schematics so if you know electronic you can start to probe around and see what is working and what isn't. These units use a stepper motor so the fact that it is tracking fast tells me either the pulses going to the IC ( SAA1027)  that controllers the stepper are too fast or there is missing phase going to the stepper. If you miss a phase the next phase will be 2x larger then it should be hence the motor moves to fast and most likely it would make a noise.

 

                https://www.clearlin.../technotes.html

 

                https://www.datashee...9666783#package

 

    - Dave 

[Rick-T137]

I have a Meade 2080 LX6/Premier where the Dec motor has given it up, so I use it without the hand controller and just use the manual knobs (fine in Dec, a little tricky in RA). My other scope is a Meade 2080 LX3 that has been de-forked and I run it on an EQ-5 mount - and it is awesome!

 

Is there life in these old scopes? ABSOLUTELY!

 

If it were me, I'd take it for a spin on the Moon first. Does it come to sharp focus with your lowest power eyepiece? How about the other ones? I find the best ways to ensure good SCT performance are:

• collimation (I just follow the instructions in the Meade manual - that has worked fine for me for decades)
• insulation (ie: Reflectix) - doing this will negate having to wait for it to acclimate before providing the best views
• be aware of the seeing conditions - if you can get sharp focus at 100X but 200X or higher doesn't look so good, then experiment to find the eyepiece that works best. For me living under the Jet Stream, most nights it's my 15mm eyepiece that yields 133X

Clear skies!

 

Rick

[MGAR]

You cannot go wrong with an LX5. These give very nice lunar and planetary views. The fork mount is my favorite, and I wouldn't change it for anything. Just roll it outside and point it toward the north, and you're golden.

 

I do mostly visual, so I don't use the controller at all.

 

Get a dew shield if anything, you can make them out of old yoga mats. If you have the portable battery pack, use it. Mine tend to last 6-8 months for use.

 

Most of all...cats like em!

 

With the metal dew shield your scope becomes a yard canon and the neighbors start getting nervous!

 

Cheers,

Gary

[deSitter]

You cannot go wrong with an LX5. These give very nice lunar and planetary views. The fork mount is my favorite, and I wouldn't change it for anything. Just roll it outside and point it toward the north, and you're golden.

 

I do mostly visual, so I don't use the controller at all.

 

Get a dew shield if anything, you can make them out of old yoga mats. If you have the portable battery pack, use it. Mine tend to last 6-8 months for use.

 

Most of all...cats like em!

Cat on a Cat.jpg

 

With the metal dew shield your scope becomes a yard canon and the neighbors start getting nervous!

IMG_4961(1).jpg

 

Cheers,

Gary

Nice cat - and drive corrector

 

-drl

[deSitter]

You cannot go wrong with an LX5. These give very nice lunar and planetary views. The fork mount is my favorite, and I wouldn't change it for anything. Just roll it outside and point it toward the north, and you're golden.

 

I do mostly visual, so I don't use the controller at all.

 

Get a dew shield if anything, you can make them out of old yoga mats. If you have the portable battery pack, use it. Mine tend to last 6-8 months for use.

 

Most of all...cats like em!

Cat on a Cat.jpg

 

With the metal dew shield your scope becomes a yard canon and the neighbors start getting nervous!

IMG_4961(1).jpg

 

Cheers,

Gary

I don't think I have ever seen the full Monty this way! I have one of those plastic dew shields for my 7" Mak and it is a little embarrassing - but practical!

 

-drl

[StarryEyedSwede]

Thanks all for the encouraging responses! I have seen some posts with very mixed opinions about old SCTs from the late 80s or early 90s so I am not sure what to expect. I really hope my scope will turn out fine and not be a hopeless case.

 

 I worked on one a long time ago. I think that if you unplug the handcontroller it will still track at the correct rate. If it does then the problem is in hand controller. The one I fixed had a broken wire inside the DIN plug for the hand controller  that plugs into the main panel so that is were I would  look first.

 Clear Line Technology has the schematics so if you know electronic you can start to probe around and see what is working and what isn't. These units use a stepper motor so the fact that it is tracking fast tells me either the pulses going to the IC ( SAA1027)  that controllers the stepper are too fast or there is missing phase going to the stepper. If you miss a phase the next phase will be 2x larger then it should be hence the motor moves to fast and most likely it would make a noise.

 

                https://www.clearlin.../technotes.html

 

                https://www.datashee...9666783#package

 

    - Dave 

Good insights! I know nothing about electronics but I intend to do some systematic daytime testing using the RA setting circle. Basically just running the drive for 15/30/60 min and see that the RA changes appropriately: a) with the hand controller disconnected, b) with it connected and set to 2x or 8x but no inputs, and c) while continuously pressing the W or E button. Is there any risk with doing c) for an extended time?

 

 

I have a Meade 2080 LX6/Premier where the Dec motor has given it up, so I use it without the hand controller and just use the manual knobs (fine in Dec, a little tricky in RA). My other scope is a Meade 2080 LX3 that has been de-forked and I run it on an EQ-5 mount - and it is awesome!

 

Is there life in these old scopes? ABSOLUTELY!

 

If it were me, I'd take it for a spin on the Moon first. Does it come to sharp focus with your lowest power eyepiece? How about the other ones? I find the best ways to ensure good SCT performance are:

• collimation (I just follow the instructions in the Meade manual - that has worked fine for me for decades)
• insulation (ie: Reflectix) - doing this will negate having to wait for it to acclimate before providing the best views
• be aware of the seeing conditions - if you can get sharp focus at 100X but 200X or higher doesn't look so good, then experiment to find the eyepiece that works best. For me living under the Jet Stream, most nights it's my 15mm eyepiece that yields 133X

Clear skies!

 

Rick

 

I can't remember collimating the scope back in the days, but memory is a bit hazy. My manual is a bit newer as it mentions a supplement for LX5, not LX3, but otherwise looks about the same. The procedure doesn't look difficult but I guess it will be very frustrating to use a star if I can't sort out my drive issues. "Luckily" I have time to work on the drive that since the weather forecast predicts completely overcast for the next ten days. Is there anything more about the collimation that I can test indoors or in daylight?

 

Should the tube just be wrapped in insulation? Doesn't this increase the time to reach thermal equilibrium with the surroundings? Btw, I put the scope in an unheated room so it should already be at similar temperature as outdoors. Or is it better to store it in a heated room?

 

 

You cannot go wrong with an LX5. These give very nice lunar and planetary views. The fork mount is my favorite, and I wouldn't change it for anything. Just roll it outside and point it toward the north, and you're golden.

 

I do mostly visual, so I don't use the controller at all.

 

Get a dew shield if anything, you can make them out of old yoga mats. If you have the portable battery pack, use it. Mine tend to last 6-8 months for use.

 

Most of all...cats like em!

Cat on a Cat.jpg

 

With the metal dew shield your scope becomes a yard canon and the neighbors start getting nervous!

IMG_4961(1).jpg

 

Cheers,

Gary

Nice dew shield! And cute cat!

 

I have a small pack that accepts 8 or so AA batteries. Is it that one you mean?

[MGAR]

Nice dew shield! And cute cat!

 

I have a small pack that accepts 8 or so AA batteries. Is it that one you mean?

Yes the 8 cell battery pack, I don't have to worry about tripping on power cords in the dark.

 

Gary

[MGAR]

Yes the 8 cell battery pack, I don't have to worry about tripping on power cords in the dark.

 

Gary

Yaa... just took a look at mine, it's a 10 cell battery pack. Who's counting...;-)

 

Gary

[Bomber Bob]

Beautiful Blue Meade -- looks like NOS!

[jgraham]

I have refurbed several Meades of a similar vintage, though never an LX5. Many of them came loaded with a lot of period accessories to support imaging with film cameras in the 1980s including the dec slow-motion motor and the hand controller. I usually removed all of these accessories to clean the systems up for visual use and they make fantastic star-hoppers. Oddly enough, I have done a fair amount of imaging with them, just using modern digital cameras with modern techniques such as relatively large numbers of subs taken with short exposures and high gain. This way they don't need all of the gear and they work quite well.

 

My pride and joy...

 

 

...an original 1980 Meade 2080 LX.

 

Closer to your scope...

 

 

...a 10" Meade LX6 Premiere.

[StarryEyedSwede]

Yaa... just took a look at mine, it's a 10 cell battery pack. Who's counting...;-)

 

Gary

 

It seems AA batteries come with different voltages where non-rechargable is 1.5 V while rechargable is 1.2 V. I guess it is then intended for use with the latter?

[StarryEyedSwede]

I have refurbed several Meades of a similar vintage, though never an LX5. Many of them came loaded with a lot of period accessories to support imaging with film cameras in the 1980s including the dec slow-motion motor and the hand controller. I usually removed all of these accessories to clean the systems up for visual use and they make fantastic star-hoppers. Oddly enough, I have done a fair amount of imaging with them, just using modern digital cameras with modern techniques such as relatively large numbers of subs taken with short exposures and high gain. This way they don't need all of the gear and they work quite well.

 

My pride and joy...

 

LX 2080-1a.jpg

 

...an original 1980 Meade 2080 LX.

 

Closer to your scope...

 

LX6 Setup-1.jpg

 

...a 10" Meade LX6 Premiere.

Nice-looking scopes!

 

Yes, I was also thinking about whether I should skip the RA and dec slow motion controls. What about the focus motor? Does it bring any benefit compared to manual focusing? Less prone to vibrations when fine-tuning?

[jgraham]

Electric focusers can be nice as you describe. They are particularly nice when tweaking the focus at high magnification. I often install a Meade zero-shift electric focuser on mine. I have one of the older LX motor drives for my LX6 Premiere, though it's not mounted at the moment.

 

Neat stuff.

[MGAR]

I've often debated about getting electric focuser but found using a plastic peanut butter jar lid was good enough for my needs.

Gary

[StarryEyedSwede]

Here are some pictures I took today. I pointed the scope to some trees across the lake and snapped a few pictures by holding my phone as best I could near the eyepiece. Apologies for the bleak colors but this is what you get on an cold (-7 C) and overcast day in Sweden with a bitter wind from the north.

 

I think the treeline is about 1100 m away so the theoretical half arc second resolution limit should be about 3 mm. I have tried zooming in on the pictures and as best I can judge the thinnest visible branches are 1-2 cm wide but I could be wrong. Next time I will try with a more distant cell tower where the scale of objects should be easier to establish. Note: this is with me basically just taking the scope out of a box that hasn't been opened since last millennium.

 

 

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[deSitter]

Here are some pictures I took today. I pointed the scope to some trees across the lake and snapped a few pictures by holding my phone as best I could near the eyepiece. Apologies for the bleak colors but this is what you get on an cold (-7 C) and overcast day in Sweden with a bitter wind from the north.

 

I think the treeline is about 1100 m away so the theoretical half arc second resolution limit should be about 3 mm. I have tried zooming in on the pictures and as best I can judge the thinnest visible branches are 1-2 cm wide but I could be wrong. Next time I will try with a more distant cell tower where the scale of objects should be easier to establish. Note: this is with me basically just taking the scope out of a box that hasn't been opened since last millennium.

You can star test on a sunlight glint from something distant.

 

-drl

[StarryEyedSwede]

You can star test on a sunlight glint from something distant.

 

-drl

 

True. Though our country house has trees all around so is not very suitable for distant terrestrial views. I can see the horizon in two directions but there are no man-made objects in those directions except for the cell tower I mentioned. And I am a bit too lazy to go somewhere else to observe before I have figured out if it will be worth the effort.

[StarryEyedSwede]

Not sure what to make of the need for cleaning. There looks to be a little bit of dust on the corrector plate. Here is a pic from the front with the camera light on.

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[StarryEyedSwede]

I checked the drive and with the hand controller disconnected or connected with the speed switch in the 2x position it tracked fine, exactly 1h of RA in 1h of time. But when I set the switch to 8x then it moved 5h in 1h, so 5x speed. I opened the hand controller to have a look but saw nothing that looked obviously broken or disconnected. DAVIDG, any clues on what is wrong?

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[CHASLX200]

Not sure what to make of the need for cleaning. There looks to be a little bit of dust on the corrector plate. Here is a pic from the front with the camera light on.

It's fogged up, Remove and clean.

[deSitter]

True. Though our country house has trees all around so is not very suitable for distant terrestrial views. I can see the horizon in two directions but there are no man-made objects in those directions except for the cell tower I mentioned. And I am a bit too lazy to go somewhere else to observe before I have figured out if it will be worth the effort.

Take a green spherical glass Christmas ornament and hang it from a distant tree in such a way that it can catch the Sun. The green will help with evaluating refractors I put a cat bell on a mailbox post far up my street. It stayed there for months

 

-drl

[StarryEyedSwede]

It's fogged up, Remove and clean.

 

I had a look at the manual which more or less says I can carefully clean the outside of the corrector but shouldn't touch anything else. See below. OTOH you have been around for a while so I am sure you are not just giving some random advice. Would you care to help me with some more elaborate guidance?

 

 

A NOTE ON THE "FLASHLIGHT” TEST
Approximately 94% of the light impinging on the primary mirror of the Model 2080 or 2120 is reflected by the mirror; about 6% of the light is scattered. Similarly, the correcting plate of either model transmits about 95% of the light impinging at each surface; about 5% of the light impinging each surface is scattered.
If a flashlight or other high-intensity light source is pointed down the main telescope tube under dark conditions, the total amount of scattered light will be very considerable. As a result, the optics of the telescope will appear to be of very poor surface quality. This same statement may be made of any high quality optical surfaces when given this grossly misleading "test."

 

CLEANING THE OPTICS
Perhaps the most common telescope maintenance error is cleaning the optics too often. A little dust on the surface of the correcting plate causes negligible degradation of optical performance: don't clean the outside surface of this lens unless really necessary. To remove small particles on the corrector lens surface, use a camel's hair brush (gently!) or blow off with an ear syringe (available from a local pharmacy). If further cleaning is required, a photographic lens cleaner may be used. In any case, DO NOT clean the correcting plate by taking strong circular wipes with a piece of cloth or other material: use a white "Kleenex"-type tissue and make short, gentle, radial wipes (from the center outward). Change tissues several times when cleaning the entire plate.
If grease or other organic materials (e.g. fingerprints) are in evidence on the outer surface of the corrector lens, the following homemade cleansing solution works well: 2 parts distilled water, 1 part isopropyl alcohol, and 1 drop of biodegradable liquid dishwashing detergent per pint of solution. Use only a small amount of solution and taken gentle, radial swipes, changing tissues several times to clean the corrector lens.
The above solution may also be used to clean correctors with the special High Transmission Coating (Magnesium Flouride). If your optics are so coated, take special care in cleaning to avoid scratches.
The aluminized surfaces of the Models 2080 and 2120 will probably never need re-aluminizing, if you are careful to replace the dust caps at the eye-end and corrector-end when the telescope is not in use. These dust caps also serve the important purpose of keeping dust and other contaminants off the surfaces of the corrector lens.
WARNING: Do not, in any case, remove the correcting plate from its machined housing for cleaning or other purposes. You will almost certainly not be able to replace the corrector in its proper rotational orientation and serious degradation of optical performance may result.

[Terra Nova]

I had a Meade 2120 LX5 Multi-Coated Optics Group 10” F10 SCT from around 1990. It was a heavy hog but deforking it and adding a long ADM mounting rail and handle with two sets of ADM radius blocks made it much more manageable. Still, with a 50mm finder, 2” diagonal, and using 2” eyepieces it weighed around 30 pounds. Even so, it was a fun scope! It gave really sharp views! I’ve had two Meade SCTs (10” and 6”) and three vintage Celestron SCTs (two 8” and a 5”). In all cases, both optically and mechanically, the Meades were the better scopes, handily beating the Celestrons as per my experience and in my opinion.

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