USD Calypso 1st Stage

[Green Frog]

This is what happens when I’m at home on Friday afternoon and have nothing to do!

I saw pictures on everybody’s favorite auction site offering early single hose Aqualung/USD regulators such as the Calypso of various iterations. Am I correct to assume that these 1st stage units that have a horizontal body (90 degrees from the tank connection. Am I correct in assuming that these operated on an unbalanced piston design? Some were kinda interesting, including one that seemed to have a HP mount coming off at an odd angle and another that seemed to be equipped as a J-valve. Finally the very latest ones had a fitting to mount at least 3 LP hoses.

is anybody still diving any versions of this 1st stage? Am I correct thinking that it is an unbalanced piston design? Finally, what are they like to service (or is that even possible?) I guess I’ve gotta find some useful pastimes to keep me from chasing Aqua Lung rabbits!

TIA ~

 

[Still Kicking]

NM

 

[Scuba Lawyer]

I have a couple of Calypso IV's that I've rebuilt. Great regs. Pretty sure they are balanced piston but it has been a while so happy to be corrected. The one thing to remember about those regs is that there was a recall on the 1st stage in the mid-1970's. US Divers retrofitted in a castellated-bushing to, as I recall, retain the seat in place better. The service technician was supposed to strike a mark in the chrome of the yoke up near the knob to indicate that it had been retrofitted. My IV that I bought new in the 70's always worked fine but both of mine are now retrofitted per the recall. My 2psi. M

 

[Luis H]

The Calypso IV and the Calypso III and all of the Calypso J were all balanced flow through pistons.

They are very easy to service, but finding the part for the retrofit mentioned by @Scuba Lawyer may be hard (if it need it). It is probably not too hard to make one if you have a sample.


There was an earlier Calypso that was a balanced diaphragm. The shape is very different from the later balanced piston regulators, but it also sit across the front of the tank valve.

 

[Green Frog]

Thanks for the responses so far. I’m still wondering whether I misinterpreted the picture that looked like it had a J-valve on the end opposite where the LP ports are located. Is this a thing? Does it work?

 

[James79]

Thanks for the responses so far. I’m still wondering whether I misinterpreted the picture that looked like it had a J-valve on the end opposite where the LP ports are located. Is this a thing? Does it work?

The Calypso J does. I have one on my "needs to be rebuilt" shelf, but I haven't opened it up yet. I know @John C. Ratliff has and occasionally still uses a Calypso J.

Respectfully,

James

 

[Pressurehead]

Photo please of the regulator.

I may have every part required to service that.

 

[Pressurehead]

Deleted, went overboard with photos of spare parts for these.
2 9mm amo boxes of parts.

 

[lowwall]

It's a good time to remember Bryan Pennington - Vintage Double Hose

 

[Pressurehead]

They work, IP 9 Bar .