lightyear

I have an excellent Gossen Luna-Pro light meter which requires 1.35V button silver-oxide batteries, no longer made. The replacement available 1.4V hearing aid cells wear out rapidly once exposed to air, and are not practical unless I want to carry a supply(No!). Gossen made(their and other stocks now depleted) a voltage adapter permitting use of the available 1.5V lithium button battery. The Gossen adapter fit two (required) 1.5V button cells and was designed to fit their light meter. The inexpensive online(China made) metal adapters do not modify voltage, only permit positioning of the 1.5V cells in the meter, but the higher voltage makes the meter inaccurate, and there is no way for a user to compensate for it. It can be technically done with soldering capacitors to the circuit board, but that is beyond my ability. Does anyone have the old Gossen voltage adapter they would sell me?
Thanks.

Stan

Steved3604

I have that meter around here somewhere. I'll keep this in mind if I ever find it and use it again. Great meter. I don't know if this can 'assist' but when mercury cells became extinct I started using Wein 'replacement' cells in cameras, etc. Maybe a Wein might provide the proper voltage, etc and work.

pendennis

Criscam Products has an adapter which regulates the voltage to the device. Your meter would need two of the adapters, and they're about $40/each. Here's a link to the site:

https://shop.criscam.com/products/mr-9-mercury-battery-adapter

PS - Their internal link shows that (2) adapters are required.

PPS - You may want to consider replacing the meter with a newer Gossen Luna Pro SBC. There are a lot of them for sale on eBay for the mid-$60 dollar range. A couple of years ago, I found one in excellent condition at a camera show for $40. And the 9v batteries are for sale most any place.

lightyear

The Wein cells are the 1.4V button cells I mentioned. They wear out too rapidly for me. Thanks .
Stan

lightyear

The Cris cam voltage regulating adapters are just too costly ( 2 @$40) to be able to use this old meter, and I'll be looking for the newer meter, used , that takes the 9V. battery unless I am lucky enough to find someone who has the old Gossen adapters at a low price.
Stan

StanMac Loc: Tennessee

You might contact Michael at Zacks Camera Repair about adding a schottky diode to the circuit to reduce the voltage to the meter. He reworked an old Sekonic meter for me so I could use the 1.5vdc cells. Alas, Quality Light Metric in Hollywood, who used to service light meters, has closed its doors.

The simpler method is to adjust the ASA/ISO to compensate for the higher voltage.

Stan