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Hi,
I have for sale a Tropel model 280 laser collimator with spatial filter. The optics are clean and the pinhole is in perfect condition. I believe it is 8 microns but am not 100% sure. I don't have a manual. This item appears like new and I can get a nice clean beam out of it with a Coherent 315M. This is a super nice unit at about 1/2 of what they cost on e Bay. See e Bay listing #330417949995 for a picture of an identical unit. $500 including shipping to the USA,
First to ask and pay gets it. Phil 142laser (813) 974-2378 (work) (813) 996-5114 (home)

What's the size of the output beam? 25, 50 mm or more?

Hi Ed,
The output beam is slightly divergent; maybe ~1.5 cm at the exit? It is ~15 cm at 30 feet. the diffraction pattern is clean and circular so that should mean the pinhole is OK. I cannot get decent throughput...about 15% max. Specs are 90% so I assume either the objective is wrong for the small pinhole or a coarse focus is off. I have NO idea how to open it and/or adjust that. The Z axis seems to work great (very, very fancy) but has insufficient range.

Do you have time to check it out? If you want it the price will be $400; you figure out the throughput focusing issue. The pinhole and optics are perfect. Your opinion? I will ship it on my dollar if you are really interested. No risk for you. Best.

Phil am i missing somthing here? try running a hene thru it............

i am not familiar with this unit , is a photo possible ?

I ran both a HeNe and the 315M through it. The beam looks good but it is clipping the pinhole. The Z axis cannot reach focus at the pinhole plane or the lens is the wrong power for the pinhole (same thing but not easily fixible) . I have no manual. Ed is the man; he is real pro at lasers, optics and holography. You know who he used to set up optics for right? I need a manual...or $400 from a friend. I offered Ed a shot; if he passes you are welcome to try.

If it's identical to the one on ebay, it's very cool. :dance: If nobody else wants to figure it out, I'll give it a shot! I could never figure out where those were used. Seems to belong to the period before steel top optical tables. But it's got a classical look to it, especially with a weathered wood box.

Hi Bob,
This is a small one; not the monsters on e bay but the same model. The output lens assembly depends on the expansion ratio; this may have been a 10X unit. I need a manual or a buyer who can figure the isue out and resolve it. The pinhole may be very small. Phil

See e bay listing 330417949995 for a photo of an identical unit. No wooden box.

It's up for grabs, I will pass on it. I have a Spectra-Physics spatial filter with diffraction-limited 50 and 25 mm diameter output attachments, so this piece would be redundant.

So someone else can have some fun with it!

OK Ed, no problem. Does anyone have a manual? Tropel model 280 or 261 soatial filter. There should be a coarse fucus adjustment somewhere... It looks new and the opticas and pinhole are perfect so how can the throughput be so poor unless the pinhole is really, really small. Phil

I looked at those pics. That looks like a spatial filter in a collimator's holder. You're certain that you're sending your beam into a small diameter lens, right? Not hitting the pinhole first. Could be that the Z-axis adjustment might be way inside the focus. Do you turn the large knurled end cap to adjust focus? Might want to try a beam of larger diameter for the input.