Not a clue. I can only surmise that the sudden movement causes the FGM3 to give a reading that overloads the digital portion of the converter, causing it to...
... Hello John I have the same issue with the same installation. I move it slowly about 1 degree and it locks up. Richard __________________________________ Do...
I would suggest that if sudden motion is causing lockups in the signal processor, that you have a bad connection somewhere. Easy to find. Take an insulated...
It is clearly the sensor. The circuit board is fastened down on a heavy board with standoffs and screws. The sensor is at the end of a 4 leg cable of ...
... I thought an intermittent connection might be the cause for mine and I touched up all connections. My circuit board setup is the same. The sensor has a...
Sounds like bad connections are not our problem. I wonder what the acutal mechanism of this problem is? jn ... __________________________________ Do you...
John, I believe what's happening here is that as the sensor is moved, the field strength it's 'looking' at is changed by an amount that exceeds the dynamic...
... I have my sensor pointing e/w. I just measured mine and I see 145.5khz at the input to the board and 1.27 volts output, having just zeroed on the least...
... John, is it possible that you have the more sensitive FGM-3h ? The FGM-3h can only be used in E-W direction - otherwise the sensor gets saturated... Best...
Hi Richard, At 145 kHz, the sensor is saturated. Is there ferrous metal nearby? This may sound like a stupid question, but I have to ask. Someone phoned me...
Hi Richard, An other factor sometimes taken for granted is that the sensor must be horizontal. That is, with the long axis of the sensor parallel to the...
No, it is an FGM-3 and this is movement with it already alligned in an E-W direction. jn ... +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ ... ...
Hello All I have definitly have the standard FGM-3. It is mounted horizontaly at all times. Right now it is on a wooden table about .7 meters from a concrete...
Hi Richard, Even though the frequencies seem higher than I've measured, the fact that there was a 2 to 1 change in frequency as you rotated it is a good sign....
... Hello Erich You were correct on a possible counter error. I checked with a scope and the square waveform is hardly symmetrical and that is probably causing...
Richard, I’m replying to your comment: ... Since it is on a long cable, I tried it outdoors on the same table at least 2 meters from any kind of metal with...
Hi All, Charles has a good idea. The FGM-3 output impedance is around 300 ohms +/- 100 ohms. My sensors are over 100 feet from the house, and I terminated the...
... Hello All I have a 78L05 at the sensor with suggested caps when I built the system. The termination sounds like a good fix. I wll try it and let you know. ...
Richard, Perhaps a bit more explanation about the ringing solution I proposed. Generally what you’re trying to match is the cable, not the output impedance...
For those of you with more FGM3 experience than I, I think I killed the sensor. While transferring it from it's bench setup to it's final container, I think I...
... Hello John Sorry to hear that but I have not experienced that particular issue. It probably is dead. Do you have a scope to verify that it is dead and not...
Wow. Fast reply. I'm looking at it right now. It is weird. The pulse seems "smeared" compared to what it looked like before. It is rounded off and is not ...
... Hello John I work 11 pm to 7 am so I am up until about 2pm. Try Erich's suggestion if it is on a long cable, .1ufd in series with 180 ohms. Richard ...
Hello All I installed a 270 ohm resistor in series with a .1ufd capacitor accross the input lead and ground of the chip and I read the proper frequency and I...
... Hello Charles & Erich I have operated the magnetometer on the most sensitive scale for nearly 24 hours and it seems to be working ok. Thank you for the ...
Hi Group, I was looking around for different type particle detectors to build.I came across this- http://www.lbl.gov/abc/cosmic/ Has anyone built this design...
... Hi Kim! Wrong group ;-) I'm sending a CC to the particledetctor group. Best regards, Hannes. -- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ ......
I buried the FGM3 in a housing made of 1/2" PVC. A farenheit temperature sensor was included in the same housing so I could monitor the temperature of the...
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