TL12000

[GeoMax]

Hi GeoMax,

Yes, you are right, the MD PI Polones and TL12000 have the same structure and the results have to be similar. The true is that both are "old fashion" projects with very limited possibilities.

A few words about the PI Polones. Actually, it all started in the late 1970s with the Sandbanks PI project. The complete original project was published in the January 1979 electronics magazine Practical Wireless. This was quite a popular circuit at the time. The Sandbanks PI was getting old and some components were no longer available. So, for example, the power supply circuit was changed and the “ProScan PI” was born. This was also a popular circuit for a while. Both projects Sandbanks PI and ProScan PI are available for download on the Geotech website. After many years, someone drew this circuit again, I think it was Lukas Lab from Poland, and called the detector circuit PI Polones. So the 45-year-old circuit is known today as PI Polones. It is possible that there were other descendants in between that I am not aware of. It seems that the TL12000 structure of the circuit is very similar to that of PI Polones. Maybe it is just a modified copy of that basic circuit. Who knows...

[Asanka Sanjeewa]

Dear forum friends,
I am not saying anything about this TL 12000, a person who bought the device [yellow picture posted in this forum] that I upgraded at my strong request sent a video today. Because they don't want to show their faces, the sensitivity of the device is reduced and the video is taken.The instrument clearly distinguishes the large steel knife, iron knife, brass and is only sensitive to the small gold ring. This is at the minimum sensitivity of the device.Even if an old circuit diagram is properly modified, superior results can be obtained. Its discrimination ability exceeds that of modern barrakuda and felezjoo. This is the last thing I have to say.
many regards

[Asanka Sanjeewa]

Upload failed. I can't upload the file with MP4 VIDEO

[Emersonpaz]

Upload failed. I can't upload the file with MP4 VIDEO

You can post it on YouTube and share the link here

[GeoMax]

Hi Asanka Sanjeewa

I had the fun of comparing the TL12000 and PI Polones circuits in detail and came to the conclusion that they both have the same origin, namely the Sandbanks PI from 1979. Is it possible that your TL12000 audio modification was taken from the PI Polones circuit? Because that part of the circuit is 100% identical to the original PI Polones circuit.

Both are old circuit designs but still easy to replicate for beginners and show quite good results in treasure hunting. But they are not really made for the gold fields in Australia or the USA.

[haylaz0036]

I'm just curious how it works, waiting for the video

[GeoMax]

Hi Haylaz0036,

there are many TL12000 videos on Youtube. Just look for them.

[haylaz0036]

Dear Geomax but there is no yellow map

[Asanka Sanjeewa]

Hi Asanka Sanjeewa

I had the fun of comparing the TL12000 and PI Polones circuits in detail and came to the conclusion that they both have the same origin, namely the Sandbanks PI from 1979. Is it possible that your TL12000 audio modification was taken from the PI Polones circuit? Because that part of the circuit is 100% identical to the original PI Polones circuit.

Both are old circuit designs but still easy to replicate for beginners and show quite good results in treasure hunting. But they are not really made for the gold fields in Australia or the USA.

Dear GeoMax
You are 100% right. I said that there is supply weakness in the voltage regulator oscillator. And you yourself admitted that sandbank, polones, TL 12000 are very similar. So I did this POLONES vco replacement.

[Detectorist#1]

Hi Asanka,

Where in the schematics is "voltage regulator oscillator"?

[Asanka Sanjeewa]

my Dear Emersonpaz and haylaz0036
The people who sent that video told me not to post it on social media. This is their help to my strong request. So if you send a gmail address of a member here, I can give it to you personally.It is not a problem for a foreign member to get it and upload it to youtube and put the youtube link in the forum. Please give me an address where I can upload the video.

[GeoMax]

Hi Asanka,

Where in the schematics is "voltage regulator oscillator"?

Hi Detectorist#1,

probably Asanka means the 555 timer circuit that feeds the LM7809 voltage regulator circuit part. There is a nonsense connection from the TX oscillator to pin 4 of this 555 timer. This connection is not present in the original Sandbanks PI or PI Polones. See the red arrow below. Pin 4 should be connected to pin 8 of the 555 timer IC, just as it is shown in the original Sandbanks PI and PI Polones schematic.

[Asanka Sanjeewa]

Hi GeoMax,

Yes, you are right, the MD PI Polones and TL12000 have the same structure and the results have to be similar. The true is that both are "old fashion" projects with very limited possibilities.

Hi Detectorist #
Please don't mock them as old fashioned.They were popular for so long because of the good traits.So aren't xr 71,delta pulse,Dbp 2010,anchor barracuda old fashioned? Every device has its own good and bad characteristics.Don't forget that Delta pulse, Geotech Barracuda were born based on those old fashions.There are many more examples.This is common factor to TL12000.I don't jump to conclusions just by reading circuit diagrams. So far, DELTA PULSE, DBP 2010, SURF PI, POLONESE, CHANCE, FELEZJOO, CLONE-W, PIM 2, ADMIRAL, TGSL EDU, TWO etc. have been tested in many circuits.
I say that there are some improvement features and good qualities in the tl 12000 circuit too, based on the practical experience gained, not just by looking at a circuit and making a conclusion.
These are some of the devices that I have made at home and tried in practice.

[Detectorist#1]

Hi Asanka,
It is not bad that TL12000 is your favorite child - it is your taste. Be happy with this design!

[Detectorist#1]

Hi GeoMax,
It is not easy to understand what Asanka means in his posts but we try to help him in his efforts.