mschmahl

Here I have a picture of the pcb. Your red wire goes to the ON-OFF switch (on my picture the green wire). There is a black wire on your picture from the switch to J2 on the pcb (on my pcb yellow). The missing battery-wire have to go to to J1?(can´t see it exactly) on your picture on the right from J2. But I think you have mixed positiv and negativ from the battery. I would connect battery negative to the switch and than to J2 and battery positiv to J1, but can´t check because I don´t have the Lobo ST anymore.

I think on my picture it is the red and the green wire on the bottom (circled in red). One wire goes to the on-off-switch. But I don´t know for sure. I don´t have the lobo anymore.

I think it was R34. But if you don´t have cranked up R33 to much you can use the outside Disc-Pot. For me it was ok with the outside-pot. I don´t have touch the trimmer R34.

Hi tvanwho,

you have changed with your GB-mod to some degrees your Disc also. So it could be that some stones (hot rocks, slag from melting metal, mineralic stones and so on) give you a positiv signal. So you have to set your discpot so, that the stones don´t give a signal. If you don´t change your Disc-setting you can identify this stones, wenn you switch in allmetal or pinpoint. For theis stones you get a very good signal in Disc but no or a totaly weak signal in allmetall and pinpoint modus.

I wish you a lot of good finds. Your setting could work now. I search with Sens on 10 (at start of the orange area), only with headphones. Set Disc between 1 and 2. Now nail´s come sometimes in with a choppy sound, Big iron sounds good. If you now find to much iron, set the Disc to 2 but don´t go much higher. The deeper the disc-setting the more deeper is the lobo.

Crank it up to max CCW or max CW is not a good idea. There are only slight/minimal changes necessary to set a proper GB. If you crank it up to much, you get signals from the ground itself and you change the disc also and can miss silver.

Don´t swing the battery-pack cable to much. It can easy break and than you have to solder it in new. If you tune R33 for max distance in air, you would not have a good depth in soil. Better is dig a hole in the ground outside, where you go searching. Place a coin in it and make it so deep. that you can barely get a signal of the buried coin. Than adjust R33 to get a better signal, make a little hill on your buried target and adjust r33 and so on. If you are out of balance you can get a signal from the ground with every swung or loose much depht. 

You can also pump your coil in Disc-Mode, how you gb an other detector and adjust R33 so that you dont get a signal from ground when you lower your coil  and also get no signal if you raise your coil.

All this is to make in Disc-modus only and with disc minimal and sensitivity around 9-10 (outside).

This will work. This 2 stage GB are only 2 variable resistors/pots in series. One is with a hiher Ohm-reading (the coarse gb)  and the other with a smaller one ( the fine gb). e.g. 10kohm and 1kohm (or 100 Ohm) .

Hi tvanwho!

The big pot is connect instead of R33. I have sacrificed the inbuild speaker, because i need the space for the pot and use always headphones. The dial is a special potknob for multiturn pots. My is a ten times multiturnpot. the dial is not necessary, only for setting it to factory setting. (It is around 10 on mine lobo). There is no switch and the other pot isn´t connected. For me it was important to change GB on a field. But you get very good results if you only change the settings on the inside-trimmer and later leave it how you set it.

If you change the inside trimmer to a pot you can destroy the PCB and so the whole lobo. 

Your board looks very different. Try R33 but mark it how it was set.Don´t know that it gives such different versions of the Lobo ST

Hi tom, 

Your lobo looks a bit different. I have a Lobo Super traq. I have show you wich resistor /trimmer you have to adjust on my PCB and an other PCB. The correct place is in a red circle. 

It is not U4 (stand for an IC) but it is R33 (resistor)

Sorry for the Video. I have changed the settings. Try now.

https://www.youtube.com/watch?v=6fwcMfCTkYk

Here is a youtube-video for 50 €-Cent test, that i have made today.

It is 30 cm in trashy ground (a lot of aluminium and scrap from buildings)

The photo is from the 50-Cent piece. I have forgot to film it in the video.

https://www.youtube.com/watch?v=6fwcMfCTkYk&list=UUZ6eDlRhK9aGYk9bb5x2sog

Here are some pictures. Caution by replacing the rimmer with a outside pot. I have destroyed a PCB-path and had to replace it with a wire (the golden around R34).

I don´t have an american quarter or half dollar. But i can test with a 50 Euro-Cent pice.

Hi tvanwho!

I had built an additional pot for GB in the Lobo ST, after instruction of Keith. Now the ST is a new machine. You can search deeper or individual cancel signals for hot rocks, mineralic stones and cinders from early metal production now in Disc mode. If you set the GB to wide you change the setting of Disc too and have to correct it.

But all is very nice and so i could search on a field, where my Explorer SE only gets distrubances and i could only search with minimal sensitivity. 

I also use the 13" ultimate-coil from detech. It is deeper and hotter than the other coils. Pinpoint is just the same than a smaller coil and you find also very little pieces of metal. The drawback is you can´t groundbalance it to 100% in Allmetal with Soil switch in Normal position. You have to use alkali or blk sand. 

But it is no problem.

You can also search in allmetal and get a sort of Irondisc by the sounds. I thing it is with all DD coils on the ST the same.

Sorry for my english. Greetings from Germany.