The AMF Voit Forty Fathom regulator has a unique low pressure diaphragm, which is the same as the USD original Calypso. That's a problem, because there are no longer any diaphragms for these two regulators. DO NOT THROW AWAY your old Forty Fathom diaphragm. These diaphragms have a mushroom non-return valve built into their center, and this is the unique aspect of this diaphragm. Two of us here have been successful in building a new Calypso/Forty Fathom diaphragm by using the old diaphragm's metal plate, wtth the non-return valve in it, from a new USD/Aqualung diaphragm by replacing the new solid plate with the old one. You need to carefully peel the new plate off. Make a hole for the mushroom valve, and glue in the old plate onto the new diaphragm.
PS, I have new glasses ordered; I misread your post to say "diaphragm," rather than "diagram." But, this may still be of interest to you.
It is also know as the VCR1. An exploded drawing and parts list can be found in the "manuals and catalog" section of the Vintage Double Hose site. VDH also has catalogs that have the reg listed, 1959 and 60 for sure, I didn't check others. A rare few of the second stage diaphragms are available, Rob at "The Scuba Museum" has at least one. www.thescubamuseum.com/Online%20Store/onlinestore.htm#!/US-Divers-Aqua-Lung-Voit-Calypso-and-40-Fathom-NOS-diaphragm/p/109652513/category=22552184
Once again, thanks for the info. I am afraid that before I get started I am ready too quit. Tried to take off the hose from the first stage and it broke off. Twisted off the threads. Looks like it does not use an ( O ) ring? Maybe a pipe thread? I knew from previous threads that the diaphram was problamatic. My intention was not to make it into a usable regulator but to sonicly clean it up and use in my office as a display. I thought it would look nice sitting beside my two aquamatics. As a side note, on previous threads some of you do not use a sonic cleaner. I have been using one since 1985. I would never go back, nor use only water and vinegar. gair
It can probably be fixed. If you aren't sure how, post pics and we'll help. Most of these old regs can dive again. I've rarely seen one so far gone it won't work like it should. And I've seen some UGLY ones.
That is a JIC (joint industrial council) fitting....basically a welding fitting. It did/does not use an oring, it's a metal to metal seal. It was used on a couple very early regs. I might have an old body if you want one....I think I have one in my old parts bin.