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Discussion of diving methods and equipment available prior to the development of BCDs beyond the horse collar. This forum is dedicated to the pre-1970 diving.
TylerAronson
Diver
Posts: 16
Joined: Mon Sep 18, 2017 2:55 am
First Name: Tyler
Location: Ventura CA
Contact: Website

First U.S. Divers Mistral

Fri Apr 13, 2018 4:03 am

Hey guys,
I just pick up a U.S. Divers Mistral and Stream Air for $80 and am thinking of getting them serviced for diving
What should I get done to them upgrade wise? Do I need to get any special parts to use a pressure gauge and an octo?
This is my first DH Reg so any and all advice is greatly appreciated

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Herman
VDH Moderator
Posts: 1315
Joined: Thu Oct 25, 2007 1:45 pm
Location: Raleigh NC

Re: First U.S. Divers Mistral

Fri Apr 13, 2018 7:44 am

Mistrals and Stream Airs are basically the same regs, with the Mistral being a slight upgrade to the SA. They are the most basic kind of diving regulator. Both are single stage regs, meaning that the air they supply to you goes directly from tank pressure to ambient unlike 2 stage designs which regulate tank pressure to some lower pressure then supply that to the second stage which again reduces it to ambient. There is no place to use a second stage (octo) or even modify the reg to use one. Like wise, there is no place to add a SPG, this is diving at it's very basic design. Both regs were designed to be dove with J valves. You can "add" a spg by placing a device called a banjo between the tank and regulator if your reg has a "long yoke". The long yoke was used on the later models and was an option for adding to older models, most do not have this feature so you would have to replace the yoke to use the banjo option. Bryan sells long yokes and banjos if you want to go that route. The only other upgrade available to them is the duckbill eliminator. That said, all the parts you need to rebuild them to better than new condition are available and diving them is a lot of fun. Most of us have at least one we dive.
Here is Eban showing the banjo and the differences between the long and short yoke.
https://www.youtube.com/watch?v=Ey5els2wpKs

If you want to ease into DH diving and have modern features like a SPG or octo then you will need to get a 2 stage design, the DA Aquamaster or Royal Aquamaster. Those have a lot of modifications than can be done to them to add SPGs and LP devices.
Herman

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ScubaLawyer
Master Diver
Posts: 1649
Joined: Thu Apr 08, 2010 11:25 am
First Name: Mark
Location: Laguna Beach, CA

Re: First U.S. Divers Mistral

Fri Apr 13, 2018 10:40 am

I was following that auction. You got a great deal! The Mistral is a 1958 model (you can tell because no serial number on the yellow label). As Herman said, it is not possible to add any sort of low pressure ports to either reg (for octo, bc inflator, etc...) and you would need to add a long yoke and banjo fitting to use a pressure gauge. Another option for a pressure guage is to find an old Dacor tank valve that has a HP port on it and use the reg on that. Regardless, any BC used would be manual inflate only. I love my Mistral! Mark.
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

TylerAronson
Diver
Posts: 16
Joined: Mon Sep 18, 2017 2:55 am
First Name: Tyler
Location: Ventura CA
Contact: Website

Re: First U.S. Divers Mistral

Sat Apr 14, 2018 12:01 am

Thanks for the advise guys

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Bronze06
Master Diver
Posts: 666
Joined: Tue Jul 01, 2014 5:33 am
First Name: Russell
Location: Tabuk, Saudi Arabia

Re: First U.S. Divers Mistral

Sun Apr 15, 2018 9:43 am

ScubaLawyer wrote:
Fri Apr 13, 2018 10:40 am
I was following that auction. You got a great deal! The Mistral is a 1958 model (you can tell because no serial number on the yellow label). As Herman said, it is not possible to add any sort of low pressure ports to either reg (for octo, bc inflator, etc...) and you would need to add a long yoke and banjo fitting to use a pressure gauge. Another option for a pressure guage is to find an old Dacor tank valve that has a HP port on it and use the reg on that. Regardless, any BC used would be manual inflate only. I love my Mistral! Mark.
DITTO!!!!
"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

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