TESORO GOLDEN SABRE

[cristiano.sar]

imo a fake coil, without the shielding. typical. if there is not the shield inside. KT315.
or... your connection of board to coil pins is not right.

Thanks!
Maybe the coil is fake, anyway, below is the wiring I used:

I noticed a green wire and just leave it disconnected.
The part I marked in red ( the dotted line between pins 3 and 5 ), I don't understood well for what it is so I'm doing nothing with it.
Thanks!

[waltr]

number of this diode?????????

[ATTACH]56825[/ATTACH]

Almost any rectifier diode with high enough Voltage and current rating. This is in series with the Battery to prevent damage if you connect the battery backwards.
1N4002 will work or better a Schottky diode for less Voltage drop.
You could even just install a wire 'jumper' if you NEVER connect the battery backwards.

[waltr]

Thanks!
Maybe the coil is fake, anyway, below is the wiring I used:
[ATTACH]56827[/ATTACH]
I noticed a green wire and just leave it disconnected.
The part I marked in red ( the dotted line between pins 3 and 5 ), I don't understood well for what it is so I'm doing nothing with it.
Thanks!

"Screen" if the British term for 'shield'. This is to be connected to the "Common" on the circuit (indicated with the "GND" symbol).

[cristiano.sar]

"Screen" if the British term for 'shield'. This is to be connected to the "Common" on the circuit (indicated with the "GND" symbol).

Thanks!
So, that means I must wrap the RX1 (pin 3 wire) with a shield and connect this shield to the TX2 (ground) point at the board? The only "unshielded" part of cable I have is that, a piece of wire that goes from the connector to the board ( all my 4 wires from connector at the box to the board itself are without any shield ), I also noticed if I touch any of these wires the detector beeps too. Actually, I just grounded the metallic connector ( connecting it to TX2 pin )
Below is an image of the connection inside the box:

Thanks!

[Carl-NC]

I have not seen that any Tesoro products have been copied. More likely that you do not have the shield properly connected, or maybe have the TX and/or RX coil reversed so the shield is active signal.

[kt315]

i give some pics and you have to choice needed.

[cristiano.sar]

i give some pics and you have to choice needed.

Thanks, really clear images!
Anyway I tried almost everything (reversing connections, etc) and nothing works. The coil has a good detection distance in the air but it is really unstable to touch or even when moving it above the soil inside the house (always beeping).
Maybe the Tesoro detectors designed for this coil have some kind of mechanism to ignore this interferences, I don't know.
I think it is best to use my homemade one, I just need to finish the plastic casing with the vacuum forming.
Thanks @Carl too.

[cristiano.sar]

Thanks, really clear images!
Anyway I tried almost everything (reversing connections, etc) and nothing works. The coil has a good detection distance in the air but it is really unstable to touch or even when moving it above the soil inside the house (always beeping).
Maybe the Tesoro detectors designed for this coil have some kind of mechanism to ignore this interferences, I don't know.
I think it is best to use my homemade one, I just need to finish the plastic casing with the vacuum forming.
Thanks @Carl too.

Well, I checked my ground balance pot and it was 10k value instead of 100k. After replacing it, now a get a much better behavior of the detector moving over the ground (indoors), now I need to test it outdoors, but I think it will perform reasonably good. Anyway, the coil keeps very sensitive to touch, but my main problem was really related to ground balance.

Thanks for all the help as always.

[dbanner]

Well, I checked my ground balance pot and it was 10k value instead of 100k. After replacing it, now a get a much better behavior of the detector moving over the ground (indoors), now I need to test it outdoors, but I think it will perform reasonably good. Anyway, the coil keeps very sensitive to touch, but my main problem was really related to ground balance.

Thanks for all the help as always.

You can observe from examination of the schematic, one end of the TX coil (finish end) is connected to ground of circuit. The shield is also connected to circuit ground.
Which means that one end of the RX coil (finish end) is also connected to circuit ground by virtue of being connected to the shield on the connector plug mounted on the main box. This is the case with the original tesoro golden sabre metal detector chassis box.

What does this mean?

Well, you should investigate whether or not any side of the Rx coil on your widescan coil is connected to shield inside the coil housing.

You can do this simple ly by using continuity check with multimeter.

If no end is connected to shield then you should leave it FLOATING. Which means that you should not connect the finish end of RX coil to circuit ground.
If on the other hand you find that one end of RX coil is indeed connected to the shield inside the coil housing, then also connect it to circuit ground at the other end of the cable which goes into the box.
Most important thing is which end of RX is start and which end is finish end of coil.

The only other reason for absurd continuous beeping of coil when touching with hand is if the shield pigtail wire has become detached inside of the coil housing or if the coil has Bec loose and is vibrating or microphonic. If you cannot open the coil, then you put it to one side of garbage heap.

[Ruben2000]

Hi friends!!
I'm going to repeat the TGSL; I did it last time and couldn't get the drive to work.
Here is my homemade PCB.

[Ruben2000]

Hello friends, to start assembling the TGSL PCB I am going to solder all the bridges first, then I am going to place all the components of block 11 which is the +8 V output.
And then I'll continue with block 1 which is the Tx stage.

[Ruben2000]

Because I couldn't get the 2N2907 in my local stores, I went to a junkyard and found some cards where such a component was found. Here I send you the photos

[Ruben2000]

Here are the +8V measurement photos. It looks like it's correct.
Then I will go to the TX stage.

[dbanner]

Because I couldn't get the 2N2907 in my local stores, I went to a junkyard and found some cards where such a component was found. Here I send you the photos[ATTACH]56884[/ATTACH][ATTACH]56885[/ATTACH][ATTACH]56886[/ATTACH]

Those junkyard finds are great. There's lots of very good components.

I see original 3140 chip in metal can which is classic device. You don't see those except for many fake 8 pin dip version. Many vintage metal detectors contain those for the push tune circuit.
Test the transistors. Basic junction test.

[dbanner]

Also, I draw your attention to the OP07D chips, those are superb finds.

Someone can say if they can be used in the RX preamp.