I just received a 7" x 4" x 2" unit that takes two 3 volt batteries that are a cylindrical 2 3/4" x 3/4."
I have an email out to The Battery Terminal, but just in case: does anyone know if that size exists (1970s vintage ) today, or what to substitute?
I wanted to attach a photo but my file is too big. How do I reduce the file size?

Sounds like the old mercury cell. Might be a camera battery rated at 3v that might adapt.

I use photoshop to crop and scale pics. There's plenty of alternative photo-edint programs to choose from. Some cameras can be set to a lower-res, but scaling usually is sharper. You need 800 pixels or smaller on the long side to upload directly to the forum.

-Ed

Thanks, Ed.