Tesoro Eldorado on the bench

[ivconic]

Hi ivconic...
Is this scheme right?(sign place)
Is it BC337 or 2N2222?(maybe omited) and did you make tapped coil?



Regards...

Doesnt really matter in this stage of making and experimenting. I am taking whatever closest substituion i have...from a pile.
So...use whatever you want...

[ivconic]

hi
eldorado is wonderful detector.it haves auto tune.
ivconic good job...I will try its...
good luck

Yes and manual GEB and nonmotion mode...sweet machine!

[Friday]

thank you ivconic...
I will make it free time...meanwhile how is it discirimination mode?

[ivconic]

PERFECT!

[perdica 2]

error

schematic error
is this transistor PNP tipe

[perdica 2]

[ivconic]

Yes it is PNP type. Yes it is schematic error. Not my schematic and not my error...
Originally there was 2N2907 - also PNP. I put BC327 - also PNP. So device is working excellent.
So only graphical symbol is wrong, can be corrected if does mean something to you...

[perdica 2]

hi ivconic

if you have made eldorado can you try:
- with coil from TGS (no center taped)
- replace the RX cap. 33n with 22n
i have simulated RX signal at Eldorado(6 pin LM30 and compared with RX signal at TGS(7 pin lf353),and i noted that eldorado without center tapped has double big signal (with conected center tap are the same)
i have played with RX cap. and noticed that 22n give wanted signal

[perdica 2]

or 15n

[Qiaozhi]

if you have made eldorado can you try:
- with coil from TGS (no center taped)
- replace the RX cap. 33n with 22n
i have simulated RX signal at Eldorado(6 pin LM30 and compared with RX signal at TGS(7 pin lf353),and i noted that eldorado without center tapped has double big signal (with conected center tap are the same)
i have played with RX cap. and noticed that 22n give wanted signal

Replacing the 33nF RX cap with a lower value will have two consequences.
1. The RX signal will be reduced in amplitude.
2. The phase difference between TX and RX will be shifted from the ideal position, causing problems with both GEB and DISC.

[ivconic]

Initially, just as i finished my Eldorado, tested it with TGSL coil. And yes phase was shifted much. Same as Quiaozhi i also think that playing with capacitors will not give a proper solution. Only good thing here is to make center tapped coil.
Same thing happened in the past when i experimented much with my first few TGSL's. Once i made center tapped coil and tested it with TGSL. In that case also, phase was shifted to much.
So.. solution to this is so obvious... make proper coil and enjoy!!!

[Friday]

Hi...
I made ELDORADO and it's working now... but it sometimes gives me false signal so I try its...it will be very good device..
thank you ivconic...

[porkluvr]

Eldorado spice QT

Here is a LTspice simulation that makes it easy to predict phase changes that would occur with various component changes. With the old Eldorado schematic (with wrong component values in the GCX phase reference circuit), I could not relate my Eldorado simulation results to what I knew, or thought I knew about Tesoro IB detectors. However, when Ivconic illustrated some corrections in component values, things started looking good.

It is my understanding that the received signal should have approximately +90 deg phase shift to the GCX reference - when the GCX control is at 100% clockwise (CW). (But maybe I have that backwards?) The arrows in my pot symbols point to 100% CW. If they're wrong, then simply turn them around.

The target coupling coefficient (K1) is what closes the loop between the TX and RX coils. I have arbitrarily chosen .000063. Changing that number should not affect receiver phase but it will affect RX amplitude.

As always, I have tried to remember to include all of the support files necessary to run this simulation "right out of the box", but I can't think of everything. If there's something I left out, or if something doesn't work, let me know and I will try to correct it

[ivconic]

Hi...
I made ELDORADO and it's working now... but it sometimes gives me false signal so I try its...it will be very good device..
thank you ivconic...

False signals are usually caused by coil/machine incompatibillity. Once proper coil is attached falses are reduced to very rare case.

[Friday]

ivconic you are right...
I didn't make tapped coil for eldorado.I used TGSL's DD coils.I may tapped coil this days...

Regards...