My Zeiss Ikon Universal Juwel came with a rare Kalart Synchronized Rangefinder which appears to have been custom fitted. It is coupled to the front standard allowing quick focus with the Zeiss Tessar 4.5/150 optics.
Unfortunately, the beam splitter had lost its semi-reflective coating.
Sourcing the beam splitter
Replacing the beam splitter was obviously in order. I located, after several months of searching, an eBay seller in Japan who would cut new beam splitter glass to size for me.
I messaged him and ordered a 13×16 mm piece, and in due course it arrived, precisely cut. ★★★★★ for you, Nobbysparrow!
The main thing to note regarding beam splitters is that the half-silvered surface is extremely delicate. It can simply be rubbed off with the lightest touch. So always handle the splitter as little as possible and always by the edges.
Fitting the beam splitter
Fitting is not particularly difficult or time consuming.
Firstly I removed the rangefinder guard bracket.
Next I removed the end cover.
The beam splitter is held in place by a wedge and a spring.
I carefully removed the spring and wedge.
Finally, I removed and discarded the old beam splitter itself.
Taking great care not to touch the half-silvered surface, I positioned the replacement beam splitter with tweezers and reversed the disassembly process.
The final process is calibration of the rangefinder, which I will cover in a future post.