Problem with Mineoro FG80

[Geo]

Before about a year i modified a Mineoro FG80. During this time the owner has found 2 times buried items. The last time was two weeks ago where he found approximately 500 silver coins at a depth of about 50 cm. The coins found by a distance of 30 ... 35 meters. This is not new to me because I know other examples of finding buried coins. The strange thing is that when FG80 close as one meter from the target start making a permanent beep and did not stop even after he pulled out and reinserting the battery. After a quick check i found problems between antenna and detection.
I wonder how big trend it detected in order to burn the transistor ???.
Eventually the phenomenon we call many times, maybe is it only an electrostatic field ???

Regards

[Geo]

One photo from the modified Fg80

[hung]

Problem most likely is in the ionic chamber. Maybe it was shorted out.
Years ago my partner, now deceased, had a similar behavior in his PDC210. When over an area of gold mining, he saw a strange looking rocky formation, when he pointed the device, the same thing you described happened. Sending the device back to repair, the ionic chamber was ruined. Later the rocky formation was found to be radioactive or something. If that was the case, probably radon gas was pressurized between their crystals.
Also remember what I have told here years ago. Several 2 boxes including a Mineoro 08MI had burned transistors in the location where a historical treasure is believed to exist.

Recently I could figure the code of PDC210's chip and also have to mods to it with a lot of enhancements. One great device has become even better yet.
Keep me informed of your case. I would like to know the cause of the problem when you find out.
Rgds.

[Geo]

Thanks Hung for your replay.
It will take long time to repair the FG80 because i must make new receiver because the old is full of epoxy glue. But i"ll try to measure the transistors from bottom side of pcb.
About PDC210 i believe that for good modification you must replace the uc with analog stage and to play a little with front-end.

Regards

[hung]

Well, if you had not access to the receiver stage yet, then there's a chance that one or more transistors are faulty and this could be the cause instead of the ionic chamber.

About the PDC, I think exactly the opposite. One of the reasons of great stability of the PDC was the micro controller management. My mods include changes in the toroids and passive receiver keeping the same programming. The results are very good and I am ready to change the hex programming if needed. So far this was not necessary.

[Geo]

Hi.
I have a clone of FG80 and instead of ionic chamber i use a small telescopic antenna. Results are better than original....
About PDC.... everybody has his opinion

Regards

[fmnotes]

After testing routes and surveys a small addition to this receiver makes very stable and with greater efficiency.
yes indeed a telescoping antenna helps a lot.

[taxma1981]

This receiver is more sensitive than the mineoro haha: P

http://youtu.be/0M0rZKubAh8

[humhum]

The strange thing is that when FG80 close as one meter from the target start making a permanent beep and did not stop even after he pulled out and reinserting the battery. After a quick check i found problems between antenna and detection.
I wonder how big trend it detected in order to burn the transistor ???.
Eventually the phenomenon we call many times, maybe is it only an electrostatic field ???

Regards

Hi Geo , Before few years I have also problem with my garage made Mineoro and
Some time in year not works one week , after time work self without intervention.

[humhum]

Hi Hung. I have one question , What is big different between
Mineoro FG80 and Mineoro FG 90 , maybe only with price.

[Geo]

Hi Geo , Before few years I have also problem with my garage made Mineoro and
Some time in year not works one week , after time work self without intervention.

In my occasion the things are different

[Geo]

Hi Hung. I have one question , What is big different between
Mineoro FG80 and Mineoro FG 90 , maybe only with price.

I think that the difference is the operating frequency, but i have not measure it. Maybe hung remember it.

[hung]

Hi Hung. I have one question , What is big different between
Mineoro FG80 and Mineoro FG 90 , maybe only with price.

Sorry, been busy.
Differences: FG90, more detection power and stability.
Mine has a tuning led indicating edge of calibration. Not sure if working frequencies are different or not.

[fmnotes]

Sorry, been busy.
Differences: FG90, more detection power and stability.
Mine has a tuning led indicating edge of calibration. Not sure if working frequencies are different or not.

Is right (hung) are more stable and has some extra systems.
And ion chamber and the passive receiver.

[Geo]

Well, if you had not access to the receiver stage yet, then there's a chance that one or more transistors are faulty and this could be the cause instead of the ionic chamber.

About the PDC, I think exactly the opposite. One of the reasons of great stability of the PDC was the micro controller management. My mods include changes in the toroids and passive receiver keeping the same programming. The results are very good and I am ready to change the hex programming if needed. So far this was not necessary.

Finally i repaired it. Receiver was good and the problem was at power supply. A faulty LM317 had an out of 6V so receiver was out of calibration.
Anyway.... now it is ready for new "treasure".
I attach a photo from the mini treasure that the "modified mineoro" owner found.