Wreckfinder MC4

[J.Haarbrink]

Hi,


I have a Wreckfinder MC4 proton magnetometer.


No clue what make it is.. Wreckfinder ?


I bought it secondhand.


The problem is that I cannot get it to get correct readings.


Even when I do not move the coil, the readings vary wildly from +500 nT to -500 nT.


I checked the soldering etc but cannot find anything wrong.


Tapping the PCB does not improve or worsen the readings.


Made new solderconnections to the coil, but that did not help.


(Connector for coax looked a bit worn)


Connected it to separate 24V supply.... no improvement.


Measured the impedance of coil + coax ... even when shaking coil + coax... no difference.


I do not have schematics of instrument, and do not know what to do now.


Anyone a suggestion ?


If I would connect a scope to output, would I then get valid readings or would the magnetic field in my house influence the readings to much ?


Jan

[Bill]

Re: Wreckfinder MC4

>Hi,


>I have a Wreckfinder MC4 proton magnetometer.


>No clue what make it is.. Wreckfinder ?


>I bought it secondhand.


>The problem is that I cannot get it to get correct readings.


>Even when I do not move the coil, the readings vary wildly from +500 nT to -500 nT.


>I checked the soldering etc but cannot find anything wrong.


>Tapping the PCB does not improve or worsen the readings.


>Made new solderconnections to the coil, but that did not help.


>(Connector for coax looked a bit worn)


>Connected it to separate 24V supply.... no improvement.


>Measured the impedance of coil + coax ... even when shaking coil + coax... no difference.


>I do not have schematics of instrument, and do not know what to do now.


>Anyone a suggestion ?


>If I would connect a scope to output, would I then get valid readings or would the magnetic field in my house influence the readings to much ?


>


>Jan


J, we had one of the first Wreckfinders that was put


out. There are two things to check. One, check the


sensor cable for cuts or cracks that might have let


water into the fish. Two, and this is important, you


must know what the dip switch settings are for your


area. If there are no cable problems, set the mag


up stationary, and move a large metal object close


to it. Observe the gammas or nano teslas, and then


change the dip switches until the unit settles down.


This is going to require many changes, so write


down the positions and the changes. We had to do


this when we travelled to different parts of the


Caribbean. I hope this helps. Bill

[Jan Haarbrink]

Re: Wreckfinder MC4

>>Hi,


>>I have a Wreckfinder MC4 proton magnetometer.


>>No clue what make it is.. Wreckfinder ?


>>I bought it secondhand.


>>The problem is that I cannot get it to get correct readings.


>>Even when I do not move the coil, the readings vary wildly from +500 nT to -500 nT.


>>I checked the soldering etc but cannot find anything wrong.


>>Tapping the PCB does not improve or worsen the readings.


>>Made new solderconnections to the coil, but that did not help.


>>(Connector for coax looked a bit worn)


>>Connected it to separate 24V supply.... no improvement.


>>Measured the impedance of coil + coax ... even when shaking coil + coax... no difference.


>>I do not have schematics of instrument, and do not know what to do now.


>>Anyone a suggestion ?


>>If I would connect a scope to output, would I then get valid readings or would the magnetic field in my house influence the readings to much ?


>>


>>Jan


>J, we had one of the first Wreckfinders that was put


>out. There are two things to check. One, check the


>sensor cable for cuts or cracks that might have let


>water into the fish. Two, and this is important, you


>must know what the dip switch settings are for your


>area. If there are no cable problems, set the mag


>up stationary, and move a large metal object close


>to it. Observe the gammas or nano teslas, and then


>change the dip switches until the unit settles down.


>This is going to require many changes, so write


>down the positions and the changes. We had to do


>this when we travelled to different parts of the


>Caribbean. I hope this helps. Bill


Hi Bill,


Thanks for your reply.


Tried to reply yesterday, but this site went down ... at least could I could not reply or get to it anymore.


We have been discussing the cable and found a crack in it that was apparently repaired by previous owner.


Since you also suggested that this might be the problem I will exchange the cable for as new one.


Will let you know if it solved the problem.


Thanks again,


Jan