3 Long Yoke Solutions for Mistrals and 50 Fathoms

[surflung]

Three Long Yoke Solutions
for Single Stage Regulators
- Using a Banjo pressure gauge on a single stage regulator such as the AquaLung Mistral or Voit 50 Fathom requires more of a gap in the tank connection than the original "short" yoke allows. I have found three solutions to this dilemma:
-Option 1. Install an original Mistral Long Yoke. These are occasionally available from The Scuba Museum but they are rare and only in stock occasionally when Rob gets in 1 or 2. I got one a couple of years ago and another one recently.
-Option 2. Vintage Double Hose now has a yoke nut that allows use of the 2-stage (DA Aqua Master) long yoke with a single stage regulator. 2-stage long yokes are much more readily available than single stage long yokes. This solution requires a spacer washer between the nut and the cans when using metal cans. The spacer is not needed when using plastic cans because the plastic is thicker than the metal.
-Option 3. Short Yoke with Spacer Washers: My vintage twin tank yokes have such a small valve connection, I am able to create enough gap for my Banjo SPG with the original short yoke by using spacer washers beneath the yoke nut. This solution only works when the tank valve connection is small like USD Double Yokes, Sportways Double Yokes, and Sportsways single tank valves.

- I'll post some pictures later.

[surflung]

Option 1 - An original Mistral Long Yoke


Option 2 - 2 Stage (DAAM) Long Yoke with VDH Nut


Option 3 - Original Short Yoke with Spacer Washers


Short Yoke with Spacers using Banjo SPG on a Sportways valve.

[nikeajax]

Then there's my fave solution:



Get a valve that has a built in port for an SPG, my HW on the left

Jaybird

[diverdon]

Good thread, guys. Happy Easter!

[SeaRat]

There is another "solution." Declare that not having an SPG is not a real problem, and dive these regulators vintage-style with a J-valve, sonic reserve (Healthways and Scubapro single hose regs) or use their restrictor orifice (Healthways SCUBA and SCUBA Deluxe, Scubair, Scubair II). If you are within the sport diving envelope, and don't dive an overhead environment (caves, under ice, wrecks, etc.), there really is no reason to dive a SPG. (How many of you dive a SPG, and don't look at it during the dive--I did on my last dive with the Dacor Nautilus CVS.) It is as if we are insecure not knowing exactly how much air we have left, because we cannot surface safely without the SPG telling us when to surface. To someone who grew up literally without a SPG (submersible pressure gauge, to those who may not know the terminology), it seems that today's divers are very insecure and unknowledgeable about gauging their breathing rate, the working of their regulator, etc. to tell how much air they had left. As I stated on anther thread, when the Mistral is really breathing great, you know you're down to about 500 psig. And every "vintage diver" should at one point or another experience a true restrictor orifice, and then measure the air pressure after exiting. Every "vintage diver" should have some gauge on how breathing rate affects air duration, and have a watch, compass, and depth gauge to be able to determine with fair accuracy the duration of their air supply sans a pressure gauge underwater. That's part of the fun of diving vintage--you don't have all that "stuff" other diver drag around, are more streamlined, and more independent of gear than contemporary divers.

John

[scubadiverbob]

..... and then there is my solution .... get a Hydrotwin II, and now I don't have to worry about it! Although, I do have HP ports on the two 72's I use.

[scubadiverbob]

My DAAM does have the long yoke; but, I always hooked the SPG in my tank valve. It made the youngsters, working at the dive store, look at me funny when I would take my tank in to get it filled!

[nikeajax]

"It made the youngsters, working at the dive store, look at me funny when I would take my tank in to get it filled!"

BWAHAHAHAHA!

Yeah, those Waterlungs have all sorts of ports on 'em, kinda wonderful really!

Jaybird

[surflung]

- As the photos of Long Yoke Solutions indicate, I have either Mistrals, 50 Fathoms, or some variant, configured to be capable of Banjo Pressure Gauge use in all three possible methods. I dive all of them throughout the Summer... Sometimes WITH an SPG and sometimes without. Depends on the dive. Heading down 80-120' and finishing at 30-40 feet presents a varying rate of air consumption and having a pressure gauge allows me to get the most out of such a dive. On the other hand, fooling around at 12-20 feet in the lake, I KNOW how long my air lasts because its the same for every dive... So I don't use an SPG then.
- I love my Single Stage Aqualung and Voit regulators. But due to the rarity of long yokes available for them, I used to have only one that I could use a Banjo SPG with. The Options 2 and 3 above are solutions I only came across this past year and because of them, I can now use a Banjo SPG with ALL of my single stage regs.
- The single stage regulators of Emil Gagnan are fascinating designs. All of mine are re-built to function like new or better... I swear my Voit 50 Fathom VCR2 breathes almost as easy as my modern Phoenix regs... So when I dive these things, I'm not diving them just to be "vintage". I'm proud of the fact that they are in like-new condition, safe to dive anywhere, and capable of use in both vintage and modern diving environments.

[SeaRat]

There are two other options, but only one other for a long yolk. The first is for the Sherwood duel post manifold, allowing you to dive both the single stage double hose regulator and a single hose regulator with an inflator and SPG. (This is an active E-Bay auction happening now.) I've used this option for years, and it works very, very well.

The second is to get a valve manifold connector, for connecting two tanks to form doubles. It a lot of times has a long yolk, if you want to sacrifice the connector (though this Dacor one would not work--newer USD ones will).

John

[surflung]

From the Scuba Museum...

- I just received my latest order from The Scuba Museum... A genuine long yoke for Mistrals and 50 Fathoms. This one is especially nice... Sporting a re-chrome job. It's awfully pretty so I thought I'd share a picture. Now I have to decide which regulator to put it on... Hhhmmm Maybe THIS one... (any excuse to show it off)

[tomcatpc]

Whilst this subject is on...a couple dumb questions from someone who knows enough to make an idiot of himself...

Say like I'm using a USD Mistral with NO banjo fitting, just plan on using a J-Valve, I have no desire to get into cave diving and don't plan on diving deep any time soon (once I feel my heart is doing good...that might change).

So...using this regulator on a vintage J or K Valve on a steel 72...could a vintage standard size (short) yolk work just fine?

Question Two...are the regular/short yokes for the USD Mistral rare and expensive?

The reason I am asking... I have a long yoke that was salvaged off a USD Conshelf (not sure which one at this moment) to use on the Mistral I have. If a regular would work...I'd love to put the long one back on the Conshelf and see if I can get that one in order.

Also, one more thing, don't quote me, but I could have sworn I saw on one of the vintage scuba supply shop sites that a brand new long yoke was being made and sold?
Anyway...thanks
Mark

[surflung]

Excellent Questions Mark!
- The "Short" Mistral yoke should more accurately be called the Standard yoke. It's what came standard on all Mistrals and it fits all vintage valves as well as many (if not most) modern valves. I figure the "Long" yokes were an add-on upgrade for divers who wanted to use a pressure gauge with a banjo fitting.
- 2-stage short yokes and 2-stage long yokes from DA Aqua Masters are readily available. Click The Scuba Museum to check prices and availability. (I think the shorts are only $15, longs are $50)

- 2-stage yokes are not normally recommended for Mistrals, however you CAN use a 2-stage yoke if you replace your Mistral yoke nut with a VDH Yoke Nut.($10)

- (Edited) Regarding your Conshelf... I really don't know anything about Conshelf Yokes (or regs for that matter) so I edited out my previous references to those yokes. My apologies for confusing the discussion. People often worry about asking a dumb question but the most embarrassing thing is to give a dumb answer!

[SeaRat]

Mark,

A couple of things--if you dive the Mistral with the standard yolk (which is what you have), you must dive it with a J-valve to have a functional reserve on a single tank system. Diving without a J-valve is not recommended at all, as there is no positive air reserve. When I stated above that when it breaths very good, you're around 500 psig, that is subjective and should be backed up by a positive reserve from the J-valve.

Diving a double hose regulator on a single tank with a K-valve and no SPG is not recommended, unless it is a Healthways SCUBA or SCUBA Deluxe regulator equipped with a restrictor orifice. This restrictor orifice will give a positive indication of when you are low on air, as it will get progressively harder to breathe and literally force you to the surface to get enough air. If you surface when the restrictor is first felt, you will be in good shape, however.

When Eban above states that the yolk is a two-stage yolk, I think he means that it came off the first stage of a single hose, two stage regulator, and these were equipped with a slightly different yolk nut to hold it in place. They, in the newer versions, may also have been machined slightly differently. I think yours comes from an older Conshelf, and is probably the same as the long yolk for the Mistral. One way around buying a new yolk nut is to simply use the nut that came off the Conshelf on the Mistral (the threads are the same, as I remember).

'Hope this helps clarify things.

John

[nikeajax]

Hey John: did'ja make too many Easter eggs on Sunday? I noticed ya kept spelling it Y-O-L-K, and not Y-O-K-E



Jaybird