Help to identify and advise on an older Poseidon regulator

[Fitzgig]

I have scanned the board but have not found the definitive answer. I am a noob- so it could be inexperience. Apologies in advance.

My sister gifted me her old Poseidon regulator and the only thing I know is that they are nearly impossible to get serviced in the US - but that they are well manufactured. Can someone help me identify and advise me on whether it is worth the difficulty /expense to have it repaired? @rsingler seems to be THE guy to ask, but any advice is valued. Sounds stupid, but I would like to use them in the future in my sister’s memory. I think the manufacture date is 1996, back when she was a healthy vibrant dive master……

 

[billgraham]

What's the purpose of the caps? I've never used or seen them.

 

[Tracy]

What's the purpose of the caps? I've never used or seen them.

environmental sealing for cold water diving.

 

[billgraham]

I guess it'd have to be really, really cold. I used the 3960 first stages in Lake Huron to run the CCR and didn't have any trouble with them, but I wasn't breathing OC which would obviously mean more gas flow. If there is any diving colder than that, I don't want to do it! It was shocking. I used them a lot for OC diving in water that was in the 40's, but the Great Lakes is a whole different realm of cold so I can believe you need them.

 

[Fitzgig]

Thanks for the mention!
To reprise much of what's been said above,
you indeed have a solid set there - a 3960, which continues to be sold today.
Whether or not it is worth the expense of servicing is up to you, but there is a solid set of divers that love the Jetstream/3960.
I would be happy to service it for you, to get it up to speed! No one will take more care of your regs than I (and I am an authorized West Coast Service Center for Poseidon).

Now the caveats...
You have a bit of a Frankenset there. I don't know your diving experience, so I apologize if my comments are obvious.
First, there is only one second stage. Today, we dive with an auxiliary second, mostly to be able to hand off a breathing source to a buddy in distress. While you could add virtually any brand second to the set, it MUST be tuned to the supply pressure (IP) from the first stage, which is slightly lower than most brands. A second Jetstream would be more typical (and I'd be happy to sell you a good used Jetstream). Interestingly, the attached Jetstream is yellow, which suggests that originally, there WAS a second reg attached.
While there are special hoses that used to be required for the Jetstream, due to its valve, your 3960 has a pop-off, or OPV, there on the bottom, so you can use any hose with a Jetstream adapter.
If your yellow Jetstream was stored with the Dive/Predive switch in the "-" position, you may be looking at a new diaphragm, and a new servo valve is not uncommon if reg maintenance hasn't been perfect. That's another $100 in parts.
The 3960 has one weakness if stored wet. The carrier for the diaphragm can corrode and prevent sealing. The valve piston commonly needs polishing or replacement due to pitting.
And finally, the first stage is a DIN type, with a yoke adapter on it. The very first thing I'd do after you read this, is see if you can disconnect the adapter from the DIN fitting by grasping the wheel while you try to unscrew the adapter.
If you can't, and the two are really corroded together, it may be a challenge to disassemble the reg without permanently damaging the DIN bolt. More parts $$.

I also note that it is a console set. Most divers today are carrying computers, which may render one or two of the gauges redundant.

In short, servicing the set as it currently stands, is nominally ~$140, with (somewhat costly Poseidon first stage kits) and labor including spool service of your console SPG.

If you add the price of another used, but serviced Jetstream, and every single one of the misfortunes mentioned above affects you, it may max out at as much as $430 plus postage. DM me if you want to discuss further...

Trying to DM you. Being a noob, apparently I need a few more public posts…..

 

[Bigbella]

I guess it'd have to be really, really cold. I used the 3960 first stages in Lake Huron to run the CCR and didn't have any trouble with them, but I wasn't breathing OC which would obviously mean more gas flow. If there is any diving colder than that, I don't want to do it! It was shocking. I used them a lot for OC diving in water that was in the 40's, but the Great Lakes is a whole different realm of cold so I can believe you need them.

The rubber caps, at the very least, offered some minor insulation and served to keep the first stage interior free of detritus, especially important while doing some sampling in, say, a harbor, where the bottoms are often the texture of thin chocolate pudding and gear can be made filthy. They were usable, unfilled, to about 40 meters, before it would deform and no longer transmit sufficient water pressure to the diaphragm.

Add vodka to it and it served as outright antifreeze, especially valuable when using full face masks, most designed to deliver a generous amount of gas, even if it was not especially cold. I had seen ice caps form at just below 10˚C on some FFM rigs under rigorous use.

The metal caps were something else, altogether and involved replacing the secondary portion of a first stage, down to the springs and pressure plate and later having to reset the IP. They were then typically filled with a mixture of alcohol and glycerine and a flexible membrane in the gadget served to transmit the outside pressure to the diaphragm -- all of which required either know-how or a seasonal and not-so-inexpensive visit to the local tech.

The MK3 (XStream) first stage has rendered them all obsolete, since that first stage required no environmental sealing whatsoever; but there is still a contingent of commercial divers who use some of that tried and true older gear and is still quite popular in Europe . . .

 

[billgraham]

The MK3 (XStream) first stage has rendered them all obsolete, since that first stage required no environmental sealing whatsoever; but there is still a contingent of commercial divers who use some of that tried and true older gear and is still quite popular in Europe . . .

I've never tried the X Stream but I noticed when it came out that the second stage lacked the +/- switch that the Jetstream second has. I find that to be a useful feature when diving with multiple regs and stowing them on a necklace or on the bottle. Another thing I tried recently and like is the Omniswivel for the second stages. I resisted the swivels for years but when I went back to OC diving, I tried it and it is much more comfortable and you can ditch the giant stiff Poseidon hose.

 

[rsingler]

Another thing I tried recently and like is the Omniswivel for the second stages

You want a lighter weight swivel that meets your needs without the extra weight of the Omni-Swivel twisting the Jetstream in your mouth a bit?
Try @Fibonacci 's new adapter on an Atomic Comfort Swivel. Then adapt it to the exact length you want with an Omni-Swivel male end hose adapter. Simply awesome!

And yes, I'm just a little disappointed in the XStream second. While I don't find freeflow a problem as an auxiliary without the switch, and the form factor is nicely smaller, it sure is loud in my left ear, and seems to have just a hair more exhalation resistance during heavy breathing at depth.

 

[jborg]

You want a lighter weight swivel that meets your needs without the extra weight of the Omni-Swivel twisting the Jetstream in your mouth a bit?
Try @Fibonacci 's new adapter on an Atomic Comfort Swivel. Then adapt it to the exact length you want with an Omni-Swivel male end hose adapter. Simply awesome!

And yes, I'm just a little disappointed in the XStream second. While I don't find freeflow a problem as an auxiliary without the switch, and the form factor is nicely smaller, it sure is loud in my left ear, and seems to have just a hair more exhalation resistance during heavy breathing at depth.

It’s also unfortunate when you’re diving a wall to your right, as you get all the bubbles all in your face all the time. :/

 

[Bigbella]

You want a lighter weight swivel that meets your needs without the extra weight of the Omni-Swivel twisting the Jetstream in your mouth a bit?
Try @Fibonacci 's new adapter on an Atomic Comfort Swivel. Then adapt it to the exact length you want with an Omni-Swivel male end hose adapter. Simply awesome!

And yes, I'm just a little disappointed in the XStream second. While I don't find freeflow a problem as an auxiliary without the switch, and the form factor is nicely smaller, it sure is loud in my left ear, and seems to have just a hair more exhalation resistance during heavy breathing at depth.

Do you suppose that that is simply do to the tiny size of second stage diaphragm, compared to that of the Jetstream, at about twice the diameter -- which also happened to be the same as that of both Cyklon second stage diaphragms -- both of which are easy breathers?

I hadn't really noticed that exhalation issue, since I most typically use the XStream second stage guts in the Atmosphere mask, which uses that larger Jetstream housing. It still remains the best FFM that I have used, in terms of ease of breathing.

Was that observation of yours the result of those multiple regulator tests that you made in the Keys last year or the year before?

 

[Tracy]

While I don't find freeflow a problem as an auxiliary without the switch, and the form factor is nicely smaller, it sure is loud in my left ear, and seems to have just a hair more exhalation resistance during heavy breathing at depth.

I have a fix for that. Flip it over.
It will only be loud in your right ear after that.