Question...
 

Alright I didnt know which forum to post this in but the most knowledgable people are in this section thats for sure... Anyways I recentley was cleaning out my parents attic and found a really old Rangefinder In leather case and original box.

It is a Federal Long Range Rangefinder / Federal Instrument corp 114-06 rockaway blvd jamaica New York 11420

there is no year on it but has original directions. It has to be atleast 50 years old.

This is a crazy old school rangfinder hahait is pretty cool though.

If anyone knows anything about it please let me know. I have tried searching or finding a forum on antique rangefinders but no luck.

RE: Question...
 

It is most likely a coincidence rangefinder that uses trigonometry to determine how far away objects are. Should be fun to fool with it........

RE: Question...
 

Yeah I think your half right, It has a dial that you move around until the object is one it starts out blurry and almost looks like multiple deer elk bear whatever it is your looking at and the clearer it gets the more accurate the range will be... it has been confusing to try messing with the last few days :Dalot easier to just point my leica at something and press a button!

RE: Question...
 

You've got an old school stereoscopic rangefinder. It works the same way your eye's depth perception works. When you view an object through the stereoscopic rangefinder, unless the focus dial is correct, it'll look blurry and/or like two images. Then you turn the dial until the dual image focuses into one clear image. What you're doing when you turn the dial is moving the lenses so that the line of sight converges on on point. Then, through a simple mechanical computer and trigonometry the rangefinder, by knowing the exact distance between the lenses and the convergence angle, displays the range to the target. This type of ranging system has been used on naval warships for line-of-sight naval gun laying for over a century (of course, it's now obsolete).

Mike

RE: Question...
 

I remember using 1 of those while hunting groundhogs with my great uncle in the late 60s. It was heavy, very long (wide), and incredibly accurate. I believe it was a Swiss model if not mistaken. My great uncle used an .220 Swift exclusively and had his drop chart/meter to yard conversion and wind chart taped on the old homemade quick disassemble bench he'd made. He, and I (to much lesser degree naturally), made some VERY long shots on groundhogs. Back then we didn't have coyotes in the southeast. Of course I realize it's not the same model but responded merely to reminisce, and because they work exactly the same way.

RE: Question...
 

The formula is:

h = a / 2 tan(A/2)

RE: Question...
 

Wow guys thanks for all the info! It wouldnt be worth anything would it? I just plan on putting it on the wreckroom shelf as a conversation piece anyways...