AO 20, really cheap on ebay.

[apochronaut]

I'm not selling this but I have used the same microscope with great pleasure.
Any one with a little patience, a small amount of technical skill and wanting to get into high magnification DF, or transmitted fluorescence in the future might consider this, certainly at 50.00 or thereabouts. This one has a #1079 100X achromat and likely a #1116 45X achromat as well as a 1019 planachro. The 1079 takes a funnel stop to do 100X DF . These are pretty common and usually come with the condenser, of which there is almost always one on ebay for sale. I have a few funnel stops anyway, if one turns out to be hard to find.
Another 300.00 for a trino,4 position nosepiece, 4 or 20X planachro, lamp socket and transformer and this would be a really nice microscope.
http://www.ebay.com/itm/SPENCER-MICROSC ... SwZG9WlAmy

Defects. No trinocular and only a 3 position nosepiece. The trino and a 4 position ( preferably 5) are usually available in short order on ebay.
No illuminator socket or transformer.
The illuminator socket is similar enough to that on the AO 120 and some European Reichert models that they all work well. Usually only the plug needs to be changed. That for sure is the difficult item to find but one will show up.
There are led conversions available. The original 100 watt halogen is around 3400 lumens and that is pretty much necessary to get good 100X DF imaging. The led conversions are 10 watt and are around 1000 lumens, maybe less. So, in a pinch the led will work for all other uses except 100X DF .

12v. variable transformers are pretty common and there is usually one on ebay. This one says for quartz iodine, vertical fluorescence lamp but the transformer was the same for that and the 100 watt halogen and the socket in the rear is that needed for the original AO 20 illuminator.
http://www.ebay.com/itm/AMERICAN-OPTICA ... SwX6VTx-DJ
one other feature of the 100 watt AO and AO/Reichert microscopes is the on board filter carousels. the 20 has a pair of 4 place overlapping filter wheels accessible under a small door at the front lip of the base. the edges of the carousels protrude through two slots facing forward and can be rotated into place ; open 1,2,3,4, and open A,B,C,D, the filters are 31mm .

[zzffnn]

My wallet ran away from me Bad timing for me and limited space available, otherwise I will buy it.........seller did not label it as AO20, which makes it possible to end on a low winning bid.