MicrobeHunter.com Microscopy Forum

Hi, I'm no expert on antique slides but I'm pretty sure slide is from 1911 for two reasons. First in my experience the label is indicative of the 1890's to maybe the late 1920's. Second is the size of the slide. This is not definitive by any means but if my memory serves me around 1835 is when this ...

Some interesting thoughts! Thank you all for commenting. I did check it with my surface gauge and it is uneven. The tapper is about .040" across the length which is pretty extreme. There is about a .005" deviation across the width on both ends and the slide does not lay flat against the surface plat...

Got it working! As you can see from the photo it had a bad connection at one of the terminals. After tearing apart the switch I did all my testing from the resistive material not the terminal so this had no bearing on the test. When I was wiring the resister in series as Hobbiest46 suggested I notic...

Hi Bob! For me this is an interesting problem from the manucafturing side: How was this glass made? With todays float glass it is probably difficult to get such a taper. Our house is 75 years old (material perhaps a lot older) and some of the old window panes showed some interesting irregularities t...

4. I would proceed to measure the resistance of the potentiometer in series with a "233 ohm" resistor. It might give a reading that is incorrect by, say, 10-20%. I tried this several ways with several resisters but I still do not get a value. The "dead zone" between the red dots didn't get any smal...

Hi Charles, Thanks for commenting. I kind of wondered if it was created as a test of some sort but I have no idea what that could be. Otherwise I see no obvious explanation other than a mistake. Seems strange that someone would miss that during mounting but I'm certainly not exempt from such foul up...

Terry,

Your telescope looks fantastic! I assume you did the machine work as well?

Well done!

Kirby

I guess I'm a little boring because I prefer whatever the factory color and finish is in most cases. That said I agree it does make them aesthetically better in some cases. I once bought some yellow paint for one of those retro looking graf apsco stereo scopes but in the end I couldn't go through wi...

First I used four 2.2k +/- 5% resisters (they were not marked but the colors are 3 red / space / gold ) and connected them in parallel and series to see what happens. My meter says the resistance in one of them is 1.997, however it struggled to get this measurement at first. The value bounced around...

Great to know!

Thank you both for the help! I will try the second resistor and consider upgrading the multi-meter. A Fluke is overdue!

Best Regards,
Kirby

I should add there are micro nut drivers. My smallest is 5/64 but Wiha makes a 1.5mm

Kirby

In the past I have made similar tools by tapping a piece of thin-walled brass tubing over the screw/nut or whatever your working on. You might want to heat it a little but the tube will take the necessary shape. Once firmly seated remove and solder or epoxy it into another slightly larger brass tube...

The battery is good and the leads ohm out with a beeeep!

This is my meter,
http://www.snapon-bluepoint.com.sg/cate ... al-Ranging

Thanks,
Kirby

Dumb question, is it possible my multimeter can't measure the resistance if it's too low? My meter is marked 2K and I noticed if I check continuity on some resisters that are new and unused that I don't get a reading. Could this be a equipment limitation? It's a pretty basic non-auto-ranging meter. ...

Hi Michael, I did thoroughly prob the surface while working under the microscope but couldn't get a value. The area between the two red dots is a dead zone. I couldn't even get a value with the probs side by side in this dead zone. If you look closely the area I'm calling the dead zone is actually d...

Zuul,

The circuit between x and x is open. The best I could do is getting a measurement on each end.

Based on the suggestions I will hunt for a 5-15 Ohm. Worst case I end up with some spares for the next project.

Thanks again for the help!

Kirby

I use the "Mini Lock-Top Snack Containers" from Greenbrier International Inc. They have a decent seal and two locking tabs. Used to be able get 2 of them for $1 USD but the price has gone up a little. I usually put some kimwipes or 4x4 gauze in with them and there's plenty of room for a desiccant pa...

Hello, I got a new specimen cabinet and while organizing my collection I found this odd slide. Is this just a manufacturing error or is there some purpose to mounting a specimen on a tapered slide? IMG_18062020_113106_(400_x_600_pixel)_2.jpg IMG_18062020_113226_(400_x_600_pixel)_2.jpg Thanks, Kirby

Zuul, this is the best I could do. Two measurements from either end showing almost the same resistance. Does this help at all? Sorry I don't know a lot about electronics but I am very much enjoying this! I am able to do the work and some diagnostics but I have a lot to learn on the technical side. I...

I tried and tried but cant get anything out of it anymore. It's a wonder that it worked at all!

Is there anyway to make an educated guess based on the input/output?

Thanks

When you say misaligned are you referring to the binocular collimation? If so this article may be helpful.

https://www.scribd.com/doc/126976427/A- ... ollimation


Best Regards,
KIrby

Hello, I need to replace the potentiometer in this power source and I am not sure which potentiometer I need. There is no information on the potentiometer itself indicating size. It is simply marked "Alpha A C". I cant ohm it out because it's completely shot. I tried cleaning it several times which ...

I was wrong the computer I'll be using is actually an HP not a Dell. It has Windows 10 and no thunderbolt port.

model, HP Laptop 15-daoxxx
sku, 5CP14UA#ABA
processer, intel (R) core (TM) i5-7200U CPU @ 2.50GHz, 2701 Mhz, 2 Core(s); 4 Logical Pr...

Thanks!

Hi daruosha,

I have a Dell laptop with WIndows 10.

Thanks
Kirby

Hello, I have an Olympus DP25 that I would like to hook up to my Windows 10 laptop. The DP25 uses a Firewire which I have no way to hook up. The camera manual says to use an IEEE FIrewire cable and an IEEE 1394a Firewire PCI board. I started reading about hooking it up through the USB and got really...

Hobbyst46, Thank for the additional information. I will check out the software and continue to research the filters. I found some very good information on fluorescence through Leica and Zeiss. I've reading as much as I can when I have time. The Olympus uses a Firewire and I'm not sure what I would n...

Hi Bob,
Yes I am aware and I am careful. Thank you for asking
Kirby

Hi daruosha, No particular attachment to Barium. I'm just really bad with coming up with names and in hindsight I probably should have simply used mine. I probably looked around the room for a while and saw the word "Element" on something and just went from there. I am no machinist but I do some mac...

Hello, I actually joined the forum some time ago so this is my long overdue introduction. I really haven't needed to ask any questions because you folks have already answered most of them. Thank you for that! Mostly I collect 19 century microscopes or at least that's been my intent. I also have pret...