Help identify and rebuild US Divers first stage

[Bob DBF]

Even the 2nd stage could be used at 4000# service!

As long as it was attached to the first.

Unfortunately, the yoke is made for older valves, and won't fit on convertible valves and on most modern valves, as they are wider and thicker than the older ones. The good news is the reg works fine down to 40 meters the last time I had it out.

 

[Nemrod]

The problems with the Calypso J reg of the OP is not reliability. Sure, reduce the tank pressure to 2400 psi to reduce possibility of extrusion. But, the tiny, little, bitty, tinsy, little bitty exhaust valve is like trying to exhale through a straw. The inhalation part is fine but one cannot inhale until they have exhaled. These old 1085 second stages with the tiny exhaust valve and the restrictive two screw tee are very high WOB and IMO dangerous to use. At 12 or 14 years of age I could get enough air in the 10 to 20 feet of water I was usually in, now, no way.

 

[happy-diver]

Didn't you say that 15 pages ago

 

[axxel57]

The problems with the Calypso J reg of the OP is not reliability. Sure, reduce the tank pressure to 2400 psi to reduce possibility of extrusion. But, the tiny, little, bitty, tinsy, little bitty exhaust valve is like trying to exhale through a straw. The inhalation part is fine but one cannot inhale until they have exhaled. These old 1085 second stages with the tiny exhaust valve and the restrictive two screw tee are very high WOB and IMO dangerous to use. At 12 or 14 years of age I could get enough air in the 10 to 20 feet of water I was usually in, now, no way.

Finally I learn somebody who seems reporting personally of problems exhaling from a Vintage 2nd.
I read about it a couple of times, but never ever heard of somebody personally that he/she experienced real problems with the exhaling process.
Years ago I was asking if somebody here in the forum had personally experienced real problems with this issue, but nobody came up.
That a high cracking effort (CE) can be stressing and dangerous seems clear, so Scuba Engineers have been trying to reduce the CE for decades.
There seems to be a technical limit which more or less has been reached.
Since the 'exhaling effort' (EE) is part of the WOB values on the ANSTI Test Machines, it seems that manufacturer have began to concentrate their efforts to lower their WOB numbers by designing more efficient exhaust valves instead of concentrating on lowering the static and 'dynamic' CE.
That's completely okay with me, but I have never understood why the EE could be in practice as important as the CE.
I see that the loop would be difficult to put in numbers in a different way as is done, but if I look on an ANSTI loop of a certain 2nd, I just check the CE part and it's 'Venturi Behavior', the EE doesn't matter too much to me.
So if a 2nd has very good WOB numbers because of extreme low EE values, it doesn't makes it to me automatically an extraordinary good 2nd.
Sure it is an advantage if a 2nd has a low EE, but does that mean that using old US Divers or SP 2nds is 'dangerous'?
I mean, also those regs in the 60ties and 70ties had been designed by engineers with the means of their time.
Anyway, at least I know now a witness who seems to confirm that a higher EE is not only in theory problematic, but also in practice.
Maybe some more come up with their bad experiences with a high EE as it is produced with regs like the US Diver or SP or similar Vintage ones, because in my 40 year diving experience with more than 4000 dives, diving very different models I have never experienced practical problems while diving with the EE.

 

[Nemrod]

The original two screw tee 1085 with the small exhaust valve has the same inhalation cracking effort and effective Venturi as the last of the line Conshelf 14 1085. It is the high exhaust effort that is, for lack of better description, exhausting to me and potentially dangerous if the diver were to get into a circumstance where some sustained effort might be required and CO2 retention. Any place in the wild that could happen, in a swimming pool probably not.

This 1085 is good:



All versions of the 1085 share the same case. The later large valve, plenum and slip on tee had the two screw holes soldered over and a plenum added. Thelater ones also have the low friction rivet in the lever, otherwise they are the same:



Back in the day, we did not know what we did not know. That a then 14 yo boy could dive in shallow water with no problems does not mean that now at near 70 I could do a strenuous dive or even a relatively shallow dive and not notice that the old Calypso just cannot mimic my breathing. And that is what a good regulator does, mimic our breathing cycle. Cracking effort, Venturi inhalation and exhaust are all equally important and the old 1085 fails on the exhaust part. I darn sure notice it and the headache I get from CO2 retention after extensive use is noticeable. And while on the subject, the SP 109 exhaust 26mm valve is minimal though acceptable. I do notice the exhaust effort. One thing that I see, my mask fogs up. It is because I am exhaling through my nose to relieve the exhaust effort. This only happens to me with old regulators with the restrictive exhaust valves and tees, to include the 109.

 

[2airishuman]

I have a Calypso J in active use with 1085 second stages. It does have the newer handwheel for the yoke connection.

There was a recall for these first stages related to the valve seat coming loose and sticking to the piston resulting an abrupt and complete loss of air delivery. The fix was to install a retainer that held the seat in place more firmly. There is supposed to be a dot stamped on the yoke if the recall has been performed. I have had three Calypso first stages apart and none of them had the recall performed when I got them. Parts to perform the recall used to be available from Vintage Double Hose, no idea if they can still be found now.

Hose routing is somewhat problematic on these regulators if used in a modern configuration. It works best to add a 90 degree fitting for the BC power inflator hose.

 

[Green Frog]

Now that you mentioned Vintage Double Hose, I’m wondering whether anyone is buy/taking over his inventory (which I assume was pretty extensive) and hopefully planning to continue selling it(?) Scuba Museum has some old stuff and the larger commercial outfits have some of the parts if you know where to look, but VDH seemed to have about everything!

 

[Nemrod]

Now that you mentioned Vintage Double Hose, I’m wondering whether anyone is buy/taking over his inventory (which I assume was pretty extensive) and hopefully planning to continue selling it(?) Scuba Museum has some old stuff and the larger commercial outfits have some of the parts if you know where to look, but VDH seemed to have about everything!

The Scuba Museum, google for it.

 

[axxel57]

The original two screw tee 1085 with the small exhaust valve has the same inhalation cracking effort and effective Venturi as the last of the line Conshelf 14 1085. It is the high exhaust effort that is, for lack of better description, exhausting to me and potentially dangerous if the diver were to get into a circumstance where some sustained effort might be required and CO2 retention. Any place in the wild that could happen, in a swimming pool probably not.

This 1085 is good:



All versions of the 1085 share the same case. The later large valve, plenum and slip on tee had the two screw holes soldered over and a plenum added. Thelater ones also have the low friction rivet in the lever, otherwise they are the same:



Back in the day, we did not know what we did not know. That a then 14 yo boy could dive in shallow water with no problems does not mean that now at near 70 I could do a strenuous dive or even a relatively shallow dive and not notice that the old Calypso just cannot mimic my breathing. And that is what a good regulator does, mimic our breathing cycle. Cracking effort, Venturi inhalation and exhaust are all equally important and the old 1085 fails on the exhaust part. I darn sure notice it and the headache I get from CO2 retention after extensive use is noticeable. And while on the subject, the SP 109 exhaust 26mm valve is minimal though acceptable. I do notice the exhaust effort. One thing that I see, my mask fogs up. It is because I am exhaling through my nose to relieve the exhaust effort. This only happens to me with old regulators with the restrictive exhaust valves and tees, to include the 109.

Yeah, okay, didn't think about those models even having the old Calypso and Calypso J with the small exhaust tee, I just never dived them, so I cannot talk from own experience.
Maybe I will try them when I have the opportunity later this year.
Those first exhaust valves have been really small in diameter, so maybe you are right, they wouldn't be perfect for every diver and every dive profile.
Still wouldn't consider them as 'dangerous', but I know now what you mean.