Barringer M123 Proton Magnetometer

[oldfart]

I was able to buy an apparently working mag off Ebay, I say apparently because ther was no "fish+cable" with it, however it powers up and produces random results with tuning etc so now I urgently need to hear from anyone with experience of these or with info on where to obtain a circuit diagram or manual
The M123 has been extensively used on arctic geophysical survey vessels and so should be quite sophisticated design, what I want to be able to do is find a pair of ships documented as lost around 1620 in my area of the Caribbean (not treasure ships but would probably have bronze cannon that local museum would like)
About 40 yrs ago I got the experimental proton mag from Planet and had to make a fish for that , remember the bottle was distilled water about 3 in diam but have forgotten wire guage and number of turns.
Any info or guidance would be most welcome.

 

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[Dinkydick]

There is a table contained in the construction plans of a proton precession magnetometer on the
internet. A google search under magnetometers should get you the article by Dr. Jim Koehler.
He has information for solenoid (the type you explained) and toroid sensors.

Dinkydick

 

[oldfart]

Thank you sir, I will try that Sunday (day of rest, sometimes)

 

[treasurediver]

I own a Barringer Magnetometer and would sell it for a decent offer. Also have full schematics for it. make an offer for a copy.
Treasurediver

 

[oldfart]

Hi Treasurediver, is this the M123 that you have, have you used it with any success ?
What sort of offers are you looking for for
1 magnetometer complete with fish and schematics
2 Copy of schematics
3 Details of sensor/fish construction

 

[treasurediver]

The mag has been very usefull to me, located many old wrecks. Getting too old myself so am looking to sell all of my stuff, that is metal detectors . magnetometers (2) books and wreck locations and what not more.
Will dig up the file with the mag documentation, buried under tons of other paper works, and see what it involves to make a copy. Where are you located, oldfart?

 

[oldfart]

Thanks, located on a yacht in St Martin, Netherlands Antilles (about 100 miles south of US Virgins.
Coming up to 78th birthday April but still researching, hoping to look for 2 wrecks listed in Marx book
Reputed Admiral of Flota chased Dutch ship which sank and thereafter Spanish ship sank whilst picking up survivors.
Think Dutch may have been located since a Dutch bronze cannon was lifted in the area in 1992, details were sent by local museum to Holland (gun maker etc) but no info obtained.

 

[treasurediver]

Hi old,

congratulations, to be still searching, ... I wish I was so fit, am "only" 62 but have no more boat and live on my farm now in Venezuela. I am sure there are many wrecks near St. Martin and the other neighboring islands. The problems are usually the local archaelogists that do not want to let anybody touch the wrecks. The Barringer Mag will be of great help in finding the wrecks.
About my mag ..... have done some digging, the mag itself is the model 234 the newer one (actually had only about 5 hours of use)
The sensor is still the same one though. have also found the schematics of the 234 but I know that somewhere I have the schematics of the 123 that I used for many years. Will keep digging.
If you intend to build your own sensor, I could be of some help, have buils several before. The biggest problem will be the cable. Many cables produce signans when moved.
greetings treasurediver

 

[oldfart]

Thanks agaim, Venezuela must also be nice place to live.
I guess people do not always tell the authorities, heard mention of gold coins found just north of here but no one saying much since coins seem to be worth 20,000 each as antiques.
Dont know what is important in fish design, I built one 35 yrs ago for the first Planet mag that was very succesfull
Who were the Barringer manufacturers, Barringer Research??

 

[treasurediver]

Hi oldfart,
attached, a specsheet and the address of Barringer Research.? On the sheet you see the visual of the sensor. The cost of the sensor and cable assembly is probably around US 5000 now. I am curious as of what kind of coin could reach such a high price.
Regards Treasurediver

 

[oldfart]

Thanks a million, no wonder my Google did not turn up much I was searching gor M123 instead of SM123, will intensify search when instrument arives here in St Martin, I have stuff sent to a forwarder in Miami so everything takes time. Meantime I must peruse your specs and buy some copper wire, maybe abot 20Guage off Ebay and find some friend with a lathe to wind a coil ( or double coil to reduce losses) and must find suitable dimension bottle and make former for coils.
Plenty to keep me busy and dreaming!!!

 

[treasurediver]

The Barringer 123, uses a toroid-solenoid coil, the wire is about 16 gage if I remember right. I could open the Barringer sensor that I have here and look at it. That sensor is wound on a wax core. once the sensor is wound the wax is melted away and leaves only the wires. The bigger problem is to get theright kind of tow cable for marine use. Most coax cables generate noise at any movement. The original barringer cable is very good but I dont know offhand who produces it. Some more Google search.
I have several nice toroid coils already wound but they are not according to the Barringer specs. Would need some tweaking.
regards Treasurediver.

 

[oldfart]

The good news is that the mag will be delivered ex Miami by air on Tuesday so great anticipation.
You mention winding the toroid on a wax core, I guess then the bottle of parrafin/water goes inside the centre of the coil, I had at first thought the coil was wound around a toroid water containing core which would be difficult to locate!

 

[treasurediver]

First let me correct the error on my last post. I wanted to say cylinder-toroid.
The sensor liquid, the Barringer originally uses kerosene, goes into the sensor housing, filling the whole housing, it is important not to have any air bubbles floating in the liquid because they interfere when the sensor moves with the waves.
On the specsheet you see the sensor housing, made of silicone rubber, but it could also be made of fiberglass, I would make it a different shape than the original. The place the sensor inside the housing and fill the housing with kerosene. The Geometrics magnetometer sensor uses 2 cylindrical coils at 60 degrees angle inside a cylindrical shaped housing filled with kerosene.
I measured the sensor/cable assembly of the Barringer and found it to have a DC resistance of 7.4 Ohms, could not measure the Inductance for some unknown reason ( maybe somebody on the forum can help here?) On the end of the cable closest to the console, there is a tuner box. The sensor with cable, without tuner has a resonant frequency of 9 kHz, with the tuner it has 6KHz. This does not make too much sense to me at present, but probably the additional capacitance when the console is hooked up will bring the resonant frequency down.
Regards Treasurediver

 

[oldfart]

Thanks, the arival tomorrow will tell if there is a tuner box or not with it so will have to take it from there!

 

[oldfart]

Well it arrived OK, but looks a little different.
The whole thing is mounted in a panel to screw to shipboard console and is similar to your pdf's but has an additional 2 wide maybe 10 wire ribbon connectors which come out just behind the recorder and go to a multi position rotary switch to the left and calibrated in 1000 nT divisions, what that is for I do not know.
Have not had time to open it up since my refrigeration packed up the other day and thats vital!!!

 

[RossMJohnson]

First let me correct the error on my last post. I wanted to say cylinder-toroid.
The sensor liquid, the Barringer originally uses kerosene, goes into the sensor housing, filling the whole housing, it is important not to have any air bubbles floating in the liquid because they interfere when the sensor moves with the waves.
On the specsheet you see the sensor housing, made of silicone rubber, but it could also be made of fiberglass, I would make it a different shape than the original. The place the sensor inside the housing and fill the housing with kerosene. The Geometrics magnetometer sensor uses 2 cylindrical coils at 60 degrees angle inside a cylindrical shaped housing filled with kerosene.
I measured the sensor/cable assembly of the Barringer and found it to have a DC resistance of 7.4 Ohms, could not measure the Inductance for some unknown reason ( maybe somebody on the forum can help here?)? On the end of the cable closest to the console, there is a tuner box. The sensor with cable, without tuner has a? resonant frequency of 9 kHz, with the tuner it has 6KHz. This does not make too much sense to me at present, but probably the additional capacitance when the console is hooked up will bring the resonant frequency down.
Regards Treasurediver

I have a few points of clarification:
1. You must have some bubbles in the sensor fluid or if you seal the sensor with no "expansion bubbles" when it sits in the sun it will crack and leak due to vapor pressure.? What causes noise is any amount of sea water in the fluid, not the bubbles.? We recommend Wizard Charcoal Lighter Fuel, but kerosene would be a reasonable replacement.? Do not use white gas or unleaded gasoline as eventually it will strip the lacquer off the coils and and cause a "shorted turn" which will kill the signal.

2. There are two types of sensors.? One is the omnidirectional type toroid and the other is a huml-bucking pair of solenoids wired in series opposed, looking like binoculars.? The cylinder coils should have roughly the same internal diameter as their height.? I believe that the 123 uses 15 millihenry inductance coils, probably with about 4 ohms total.? You will need an inductance bridge to tune them up. Read the specs to make sure.? We? would compensate (wrap another turn or two around the dual coil assembly) to maximize hum bucking (ac rejection), but you probably don't need to do this.? Try grounding or ungrounding the mag chassis to minimize reading jump.

3. Geometrics uses 3 coils oriented at 120 degrees to each other so that regardless of the sensor fish spin, one coil is always at right angles to the earth's field angle (field inclination or dip angle).? Our newest type of sensor is the cesium vapor mag which does not use proton precession as a basic principle but is based on the atomic clock principle.

Ross
www.geometrics.com

 

[treasurediver]

Thanks Ross for your clarification. I have used Geometrics magnetometers in the past and was very satisfied. I agree with you on the air bubbles. Probably what happened with that sensor that gave me problems, was that the rigid housing bloated when it got hot in the sun. I noticed a few drops of kerosene leaking. Then it sucked in sea water when it cooled off underwater and this is why it worked very badly afterwards.
As for the Barringer mag, it uses a flexible silicon or polyurethane rubber housing that can expand and contract as needed, so we always filled it right to the top and were carefull not to leave any bubles.
Would you care to give us advise on the cable to use? Who manufactures good coax cables for marine use?
regards Treasurediver

 

[oldfart]

Still watching avidly inbetween designing, finding and installing refrigeration parts
all info will be ultimately usefull I am sure, when I can clear a table and put the mag on it to work on
Its obviously very complex from viewing the spare set of 4 or 5 boards that came with it plus numerous other electronic parts!

 

[Brooks747]

Hi old,

congratulations, to be still searching, ... I wish I was so fit, am "only" 62 but have no more boat and live on my farm now in Venezuela. I am sure there are many wrecks near St. Martin and the other neighboring islands. The problems are usually the local archaelogists that do not want to let anybody touch the wrecks. The Barringer Mag will be of great help in finding the wrecks.
About my mag ..... have done some digging, the mag itself is the model 234 the newer one (actually had only about 5 hours of use)
The sensor is still the same one though. have also found the schematics of the 234 but I know that somewhere I have the schematics of the 123 that I used for many years. Will keep digging.
If you intend to build your own sensor, I could be of some help, have buils several before. The biggest problem will be the cable. Many cables produce signans when moved.
greetings treasurediver

Hello, I'm trying to reach TreasureDiver, who has apparently moved to a farm in Venezuela. Are you out there? I'd like to exchange information. Brooks in Houston, TX