TR locator / 2 box

[GeoMax]

I see that the project is virtual.
I don't see a developed project on the table.

Yes, as I already mentioned… A photo of your test setup would be helpful. Perhaps we can spot an error or confirm that your test setup is correct.

[pechkata]

Yes, as I already mentioned… A photo of your test setup would be helpful. Perhaps we can spot an error or confirm that your test setup is correct.

But how do we eliminate errors virtually?
Each chain operates differently on the table.

[ivconic]

I've known about Gary's schematic for a long time, but I've never made it.
In the meantime I had a pair of TM-808s, a Fisher Gemini II and III and finally a TF-900 that I successfully reverse engineered.
What I noticed with all the 2box mentioned is that the mechanical balance is CRUCIAL!
Between TOP performance and ZERO performance, the difference is sometimes only 1mm of mechanical imbalance.
Although I don't know anything about that schematic... I would recommend first to make an assembly that has a perfect mechanical balance.
...
I think that the practice of making ordinary "DD", "OO" and concentric/coplanar coils could be very successfully applied here.
You just have to imagine that they are two coils that are placed at 90 degrees in space, at a certain distance,
and that every movement of one of the coils is a drastic jump (or drop) of the signal on the other.
Or go in reverse order!
This is a good idea!
Build a literal "DD" coil to spec and see how it works.
And when it works for you with "DD"; then transfer the acquired experience to the 2box assembly.

[kt315]

i did see TF900 constantly in job by my friends and have to say it has lower sens than delta pulse with ramka coil meter on meter. but TF900
is more adaptive to go in a forest. delta sees something on 3 meters of deep while TF900 does see nothing.
i had both TM-808 and TF900 in repair and TM-808 was with newest board, on SMD.

[ivconic]

Such a thing was to be expected, the TF-900 is not some "top" design, the TM-808 is a much better machine.
I can't lie that I tested the TF-900 at depths greater than 1.5-1.8m, so I can't claim anything about greater depths.
Delta Pulse with a larger coil can really achieve impressive results, but only on large objects.
TF-900 (as well as others from the list) still have their application, and how!
In seasons when the grass is very tall and when ordinary coils cannot reach the ground; and looking for large objects; 2box is a very good solution there.
However, if you ask me; of the "dedicated" 2box, TM-808 is certainly the best, while of the detectors that have a "2box" accessory;
XP Deus 2 and Garrett GTI 2500 definitely have no competition.
I would even dare to say that the GTI 2500 is superior over XP.
But... the devil is in the details!
I don't think this topic deserves my endless scribal observations, do you?

[kece hon]

Thank you for the feed back
THIS IS MY full SETUP

small clips to put different capacities
two in red in parallel for RX
green and white in series for TX

Mechanical arms with graduations to adjust the distance between TX Rx loops

the actual PCB board with scope probes Tx , Rx
Thanks again
any valubale comments would be very helpfull

[kece hon]

Yes, as I already mentioned… A photo of your test setup would be helpful. Perhaps we can spot an error or confirm that your test setup is correct.

Thanks i posted some pics

[kece hon]

But how do we eliminate errors virtually?
Each chain operates differently on the table.

Thanks i posted some pics

[kece hon]

Such a thing was to be expected

Thanks i posted some pics of the setup

[kece hon]

i did see TF900 constantly in job by my friends and .

Thanks i posted some pics of the setup

[kece hon]

Yes, 0.8 is OK. Place oscilloscope probe directly across the TX coil, before the series capacitor.

Thanks
it was already setup like this way , also i posted some pics of the setup
Maybe there is something not right in my setup

[kt315]

Thanks i posted some pics of the setup

read 49 pages 2 boxxxx - Geotech Forums (geotech1.com)

[kece hon]

read 49 pages 2 boxxxx - Geotech Forums (geotech1.com)

i did, three times actually ; i followed most of it to make mine
i remember you commenting on it a lot did you make a fully functionnal one back at the time ?

[pechkata]

[GeoMax]

Hello Kece Hon,

Thank you for the picture of your coil setup and detector. Please compare the coil in the picture Pechkata posted of the original T/R Locator with your coil. You will notice a significant difference. The shape might be negligible, but the winding technique could be the issue. The windings in the original T/R Locator are well wound. Your coil needs some work. This could also be one of your problems. I'm not entirely sure, but doesn't the original T/R Locator coil also have a shield?