Recent content by Alexo

This is the one I finally went with: https://www.advancedphotonix.com/media/pages/our-products/light-dependent-resistor-ldr/nsl-6110/ecad74296a-1718287441/ds-nsl-6110.pdf I was able to calibrate against a Pentax Spotmeter III and it's hard to tell the difference in spot precision. Because this...

UPDATE!! IMPORTANT PLEASE READ !!! Seems like I jumped the gun. I was able to calibrate the Ranger 9 against a modern Sekonik, not problem. But after reviewing Ranger 9's original manual I realized that the number scale on the needle is not absolute EV value and neither is the EV Window. The...

Checkout the size of the Pololu S7V8A I used, maybe it fits in your design. I think you're better off with a DC-DC like this one that will do step-up and step-down and if you give it enough V (e.g. 3x CR1632 = 9V) you could easily and very efficiently regulate 5.4V throughout the whole lifetime...

Can you please re-link the article you referenced here in Photrio? I could not open it.

Oh !! so sorry for that !! It's a tiny Pololu DC-DC I forgot to put that part in the guide. It's ideal because of the size, low power consumption and the voltage range. Note that if you don't have a power switch (the Ranger 9 automatically closes the circuit when you press the read button)...

HI all ! I just finished rebuilding a beautiful Ranger 9 I got off EBay. The needle was moving but did not zero out; this is a typical failure mode of the 50+ year old CdS cell. So I decided to take it apart and replace the CdS, as well of the need for Mercury or Silver Oxide batteries. The...

OK. I think I got everything in the guide. Let know how it goes and if anything needs correcting when you attempt it.

You're very welcome. I should update the battery part later today and finish the guide. I will also publish the STL files for the 3D printed parts and other documents. Stay tuned!!

Do you recommend any specific wavelength or Kelvin Temp value for the light source ? Here is a draft of what I got so far: https://www.ifixit.com/Guide/Weston+Ranger+9+Lightmeter+CdS+Cell+and+Battery+Replacement/213318 The batteries won't arrive till Thursday so I wont be able to 3D print the...

OK, so I got the parts and I did the build, and it worked out GREAT! Probably going to publish in iFiX it first and then link to here on another post. The CdS I got is almost exactly the same as the original one, if not better. It's smaller (5mm versus the priginal 8mm) so I guess it makes it...

I am installing an actual 2.7V active regulator circuit to keep the V at exactly that level throughout the lifetime of the batt. So I'd prefer a wide margin (6V) to give the regulator plenty of room to do its job properly. Silver Oxide Cells give you exactly this, if you don't have an active...

I did a complete teardown and took pictures to make a refurbishing guide. I found a pretty compatible photocell and regulator circuit and plan to use 2 CR1632 cells in series with a 3D printed holder. I traced the original circuit and have a plan to repurpose 99% of it with some slight re-wiring...

Hi there! Do you happen to have contact with someone that had the CdS replaced by QLM ? I would be very interested in buying or borrowing the meter to understand their mods. I think this meter is worthwhile to modernize and I've decided to take this as an Open Source pet project that wil benefit...