Which AO microscope

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apochronaut
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Re: Which AO microscope

#31 Post by apochronaut » Fri Sep 01, 2017 12:12 am

you have a voltmeter, I think. Is there voltage to the actual lamp holder?

MichaelBrock
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Re: Which AO microscope

#32 Post by MichaelBrock » Fri Sep 01, 2017 12:39 am

There is definitely voltage to the lamp holder. There is voltage to the individual "blocks" as well. I get a voltage across the legs of the "scissors". However, if I install the lamp deeply enough to clamp it in but leaving room for the voltmeter leads, no voltage. I am fairly certain at this point that the issue is oxidation in side of the holes where the legs of the lamp goes. I'll figure something out to clean them out.

MichaelBrock
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Re: Which AO microscope

#33 Post by MichaelBrock » Fri Sep 01, 2017 2:04 am

I didn't set out to narrate every step of the process and I apologize for rambling on. I used a fine scroll saw blade and swirled it around in the sockets and that did the trick. So we have illuminatin! and I discovered how dirty the mirror is under the filter wheels. Tomorrow I'm going to pick up some super lube and start the process of putting the stage back together.

apochronaut
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Re: Which AO microscope

#34 Post by apochronaut » Fri Sep 01, 2017 2:33 pm

MichaelBrock wrote:There is definitely voltage to the lamp holder. There is voltage to the individual "blocks" as well. I get a voltage across the legs of the "scissors". However, if I install the lamp deeply enough to clamp it in but leaving room for the voltmeter leads, no voltage. I am fairly certain at this point that the issue is oxidation in side of the holes where the legs of the lamp goes. I'll figure something out to clean them out.
Maybe to do a more permanent cleanup ; glue a tiny piece of emery paper around one of those round toothpicks and make a super fine tiny round file.

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KurtM
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Re: Which AO microscope

#35 Post by KurtM » Fri Sep 01, 2017 5:25 pm

The 45 degree mirror in the base, that bounces the illuminator's light path 90 degrees, may be a first-surface mirror that may be losing its coating; at least this is often the case in Series 10 illuminators such as 1031 and 1036/1036A. I found it a simple matter to obtain new 1st surface mirror on eBay, cut to size, and install. You can't buy the mirror on as thin glass as the original, but I got the thinnest possible and made do. It works fine.
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)gmail(dot)com
https://www.flickr.com/photos/67904872@ ... 912223623/

MichaelBrock
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Re: Which AO microscope

#36 Post by MichaelBrock » Fri Sep 01, 2017 8:53 pm

KurtM wrote:The 45 degree mirror in the base, that bounces the illuminator's light path 90 degrees, may be a first-surface mirror that may be losing its coating; at least this is often the case in Series 10 illuminators such as 1031 and 1036/1036A. I found it a simple matter to obtain new 1st surface mirror on eBay, cut to size, and install. You can't buy the mirror on as thin glass as the original, but I got the thinnest possible and made do. It works fine.
KurtM: thanks for the information. The left "field diaphragm centering knob" appears to do nothing so I think I'll be digging into the undercarriage. I'll get a chance to assess the condition of the mirror. I need to fix the left filter carousel regardless.

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Re: Which AO microscope

#37 Post by KurtM » Sat Sep 02, 2017 12:49 am

Yep, that's what I was thinking, that you might well end up digging into its innards because of that filter carousel.

Remember, there's always the old AO aficionado's Plan B: pick up a Series 20 parts-only hulk for cheap and hope all the stuff that's troublesome on yours is good on the hulk. A lot of us have had pretty good luck doing this, and ending up with maybe $300 in a perfect stand that by all rights should be worth thousands. As one who has been watching eBay for some years, I see parts-only 20's come up every now and then.
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)gmail(dot)com
https://www.flickr.com/photos/67904872@ ... 912223623/

MichaelBrock
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Re: Which AO microscope

#38 Post by MichaelBrock » Sun Sep 03, 2017 3:23 am

A few weeks ago I found a dustcap for the trinocular head on Ebay. That same seller, providencecoins, has a listing for a 1245 Aperture Viewing Unit. In a moment of weakness I decided to buy both...only to discover that he has blocked me from buying from him! I had previously asked a question about combining shipping and for a better picture of the viewing unit, which he never replied to. I guess one question too many.

MichaelBrock
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Re: Which AO microscope

#39 Post by MichaelBrock » Sun Sep 03, 2017 6:25 pm

KurtM wrote:The 45 degree mirror in the base, that bounces the illuminator's light path 90 degrees, may be a first-surface mirror that may be losing its coating; at least this is often the case in Series 10 illuminators such as 1031 and 1036/1036A. I found it a simple matter to obtain new 1st surface mirror on eBay, cut to size, and install. You can't buy the mirror on as thin glass as the original, but I got the thinnest possible and made do. It works fine.
It took me a while to figure out how the diaphragm mirror adjustment worked but I finally got it Quite clever really. I removed the mirror assembly and the filter carousels. The bottom carousel was indeed stuck on it's axis. A bit of heat again did the job. Softens the dried out grease well enough to make it pretty simple to remove.

I think maybe a previous owner has already replaced this mirror. The top edge, not clear from the image, is curved and lopsided. And does this qualify as "thin"? :lol: It might actually, I don't have much experience with first-surface mirrors.
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apochronaut
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Re: Which AO microscope

#40 Post by apochronaut » Sun Sep 03, 2017 9:49 pm

No, they aren't particularly thin. This isn't a telescope objective, or secondary mirror, which have to be physically stable over a wide range of temperatures. 1/8" glass. I think I can see a bead of glue along the bottom side and one of the side glue dabs. This is the original mirror.

Don't get too hung upon the reflective quality of this mirror. It doesn't need to be pristine.A few poor spots here and there or scratches aren't going to be noticeable, it only needs to transmit a significant proportion of the light, which in the case of the 20, you have lots of. It isn't an optic. It is first surface however, so cleaning must be done with delicacy. Any accumulated dust needs to be removed with a flow of liquid, very little pressure, just a flow and a very light sweeping action with as many very loosely fluffed up cotton swabs or sufficient cotton batting during the flow, as is necessary. They scratch easily. It is aluminum on glass.

MichaelBrock
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Re: Which AO microscope

#41 Post by MichaelBrock » Wed Sep 06, 2017 4:49 pm

I ended up just carefully rinsing that mirror. It does have quite a few spots of what appears to be oxidation but it seems sufficiently reflective for now.

I finished breaking down, cleaning, and re-lubricating the "under carriage" and finally got "first light" last night! Now I need to figure out how to use it :) Thankfully the manuals are well done.

There is quite a bit of slop in the stage controls though. I didn't pay much attention to that when I put it back together so I'm certain I can clear that up with some selective tightening and adjustment.

I think I will take that up next. The rough focus is "stiff" but I'll save that task until I have had a chance to enjoy the scope for a bit. I need to find some nice lichen and start the tardigrade hunt.

MichaelBrock
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Re: Which AO microscope

#42 Post by MichaelBrock » Wed Sep 06, 2017 6:44 pm

apochronaut wrote:That little short tube could be built on, to get to an adapter for a digital camera. You need a # 1054 eyepiece in the tube, with any reticle installed removed.
A lot of other lenses I have tried, have peripheral aberrations; mostly some coma or lateral c a. Enough to be annoying.
I have not been able to find much information on the 1054 eyepiece other than that it is a "'Field of View' focusing, photo eyepiece, with reticle -- Series 10/20" and a few threads here where you described its use with an DSLR as "the way to go". With the proper photo tube could this eyepiece be suitable for use with a cell phone adapter? I'm seeing it as a possible bridge from "simple" to "full on DSLR set-up".

apochronaut
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Re: Which AO microscope

#43 Post by apochronaut » Thu Sep 07, 2017 2:16 am

The 1054 has the same corrections as the 176 eyepiece. It just has a focusing feature, which helps parfocalize , and by my eye gives a slightly better result photographically. As relay lenses on the 20, they yield a well corrected flat image, because they are inherent lenses in a refined engineered plan optical system, so the camera sensor has good raw material to work with.
The adapter to whatever camera, is an independent function of the relay lens. Whatever phone camera or other camera you choose to use needs to be physically placed in such a way as to maximally take advantage of the image created by optical system of the 20. You have to consider parfocality, field coverage, sensor coverage and fitting and adapter flexibility.
I could tell you , how I have set up my system with a mirrorless camera but a phone camera is a little different and I haven't done that sort of set up.
Maybe there is someone out there who has?

MichaelBrock
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Re: Which AO microscope

#44 Post by MichaelBrock » Tue Sep 12, 2017 6:25 pm

Things are settling down now that Irma has passed. I have been using the scope, getting used to it. And of course that leads to more questions:

1) the manual indicates that once the upper limit of the condenser is found, the limit screw should be adjusted to stop further vertical motion. The manual shows that limit screw but does not indicate what it should be hitting to prevent fruther vertical motion. And on my scope it gets nowhere close to hitting anything. What am I missing? This picture is with the condenser right up, nearly touching, the slide.

2) After following the bright field process instructions in the manual I am getting what appears to be a good image. However, the background illumination is not uniform. There is a definite "bright spot" nearer the top of the view. My illuminator does not have the frosted glass piece that the manual describes (nor do I see where one could have been attached). Is this the issue?

Thanks,

Michael

edit: added the photo I forgot
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apochronaut
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Re: Which AO microscope

#45 Post by apochronaut » Tue Sep 12, 2017 10:09 pm

Which condenser are you using on the 20?

MichaelBrock
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Re: Which AO microscope

#46 Post by MichaelBrock » Wed Sep 13, 2017 1:25 am

apochronaut wrote:Which condenser are you using on the 20?
I have the 1248 single annulus phase condenser with a 1248 top lens.

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Re: Which AO microscope

#47 Post by Charles » Wed Sep 13, 2017 10:54 am

The limiter screw is there so the top of the condenser won't hit the slide, but it sounds like you don't need one if your condenser is at the top of it's travel and the top does not hit the slide. For phase condensers the limiter screw is longer.

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Re: Which AO microscope

#48 Post by apochronaut » Thu Sep 14, 2017 3:09 pm

MichaelBrock wrote:
apochronaut wrote:Which condenser are you using on the 20?
I have the 1248 single annulus phase condenser with a 1248 top lens.
There were a number of different condenser options for the 10 and 20 , somewhere around 10 in all. The most common ones, the abbe and abbe aspheric, non-centering versions are fairly shallow, so require a fairly short limiter screw of about 1/2" long. Other condensers with longer bodies and or lens packs, such as the several types of phase condensers require an extension to be put on the top of the limiter screw. For the phase condensers the extension is 5/8" long. It is an unthreaded dumbell shaped rod , with a machined plane end on the top and a castled female bottom that press fits over the end of the limiter screw.

These are easily removed , often not replaced and so go missing. An option is to buy a 6-32 hex grub screw, as a replacement but a little longer than the original. The original is a 6-32 grub screw, with a 1.5mm hex socket head. Getting one with an extra 1/4" length, or a 3/4" grub screw should be enough but 7/8" would be assured. I didn't do an accurate measurement.

There is a fairly limited travel under the stage for the condenser. That's the reason for the extension originally. If a 3/4" screw were installed as original equipment, then when backed off sufficiently, in order to be set for the shorter abbe and abbe aspheric oil immersion condensers, the bottom of the screw would limit the downward motion of the condenser and it would not be able to clear the stage when removed, necessitating adjusting the limiter screw a considerable distance every time there were any condenser changes or removals. It's a tight space and a finicky operation with a tiny hex key. Having a purpose made extension for the phase and achromat condensers, makes it easy.

If you are going to be using only the phase condenser, then a longer limiter screw shouldn't be a problem, because it's lower end will be buried in the threaded boss that it seats in.

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Re: Which AO microscope

#49 Post by MichaelBrock » Thu Sep 14, 2017 8:55 pm

Never Mind: User error....


It's becoming clear that my microscope is quite 'dirty'. Lots of artifacts in the image. Despite my having cleaned the eyepieces to the limit of my ability, there are quite a few "dark line segments" visible in the image which rotate with the eyepieces. I don't see any scratches but I think that must be the case.

apochronaut
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Re: Which AO microscope

#50 Post by apochronaut » Fri Sep 15, 2017 9:23 pm

If you look at where the field stop is on the cat.# 176 eyepieces, it is below the field lens, not in between the field lens and the eyelens, which is more common with many conventional eyepieces. The intermediate image is focused at the same point as the field stop. When the real image comes to your eye, artifacts that are rotating with the eyepiece are more likely to be located closer to the field stop, than not. Those located a distance away from the point of focus, are less focused and bleed into the panorama more than artifacts close to the point of focus. Usually, marks in the field, associated with those eyepieces and fairly distinct are on the surface of the bottom lens, possibly the upper surface of it, and usually due to lousy cleaning or lousy past care.

A flashlight with a focused beam should help you get that stuff off the bottom lens. Pointing up a very fine quality paintbrush.... one of the multiple 0 ones, 0000 or so can help you pick off stuff that gets left behind with regular cleaning procedure.
Of course scratches could always be there but in my experience with those eyepieces, it is usually neglected debris on the bottom lens.

Another possibility and AO is not known for this problem, to the point that I have never seen it on an AO eyepiece but I have seen a fair amount of it from other makers, is some delamination causing visual artifacts emanating from the lower achromat doublet. ....very much a longshot.

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Re: Which AO microscope

#51 Post by MichaelBrock » Wed Oct 04, 2017 6:42 pm

Kurt,

I'm thinking that I might undertake this repair. How did you remove the original mirror? There appears to be quite the bed of adhesive holding it in place. What adhesive did you use to attach the new mirror?

Thanks,

Michael
KurtM wrote:The 45 degree mirror in the base, that bounces the illuminator's light path 90 degrees, may be a first-surface mirror that may be losing its coating; at least this is often the case in Series 10 illuminators such as 1031 and 1036/1036A. I found it a simple matter to obtain new 1st surface mirror on eBay, cut to size, and install. You can't buy the mirror on as thin glass as the original, but I got the thinnest possible and made do. It works fine.

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Re: Which AO microscope

#52 Post by KurtM » Thu Oct 05, 2017 12:14 am

Oh boy, for the life of me I can't recall! That's what happens when ya get old, y' know - something for you to look forward to. :P

But I'm an old astronomer and ATM (amateur telescope maker), so probably did the standard old thing where you "floss" the old mirror off with a banjo string, and glue the new one on with RTV silicone. Or 5200 silicone, probably, in my case, since I'm also an amateur builder of canoes and kayaks (I can make anything except a paycheck).
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)gmail(dot)com
https://www.flickr.com/photos/67904872@ ... 912223623/

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