TESORO GOLDEN SABRE

[dbanner]

I have only had a cursory look also, not studied in detail, it would be handy for the guys with single channel, could be worth a go at.

Maybe I give the circuit a run on ltspice. The plot of the output waveform should reveal whether the circuit is feasible. If it is, then maybe I'll go looking for a single channel dinosaur, just for fun.
I need to read through the article carefully to see how this thing is supposed to work.

[6666]

Why,? Have you seen something on the schematic that looks suspect? It's essentially a chopping circuit. I only had a cursory look but maybe I'll check it out again in greater detail. In 1974, a dual channel scope would have been quite expensive.

I have only had a cursory look also, not studied in detail, it would be handy for the guys with single channel, could be worth a go at.

[dbanner]

My dear KT315, it is not for you to interpret my reply to the other member, but for him, in order that he may grasp on the fundamentals and basics of coil design.
If I was speaking to you, I would have said something quite different, like for example, take those two circles and put them around your neck.. and look for nearest ac wall plug.
Of course I'm only joking.

[kt315]

You can have 2 D's or 2 circles or even 2 squares if you wish.
---
sorry Delta Banner i must reminder that Tesoro design coils were NEVER '2 D's or 2 circles or even 2 squares'.
they were always classic planar. Tesoro was always kinda conservative. NO DATA on 2D coils, NOT EXISTING, people has to calculate THEMSELVES those data
and check themselves.

[dbanner]

Thanks,guys
is it possible?
the coil should be two identical circles,not two D
like the picture I put

You can have 2 D's or 2 circles or even 2 squares if you wish. The principle is the same. Balancing is achieved by overlap method.
In the concentric coplanar type coil, balancing is achieved by means of a feedback coil commonly referred to as a buck coil
So there are essentially two kinds of coils based on how the nulling of the RX coil with respect to the TX coil is achieved. Namely 1 overlap method, and 2 feedback method.

There is also a coil known as an Omega coil. But it is still a coil using overlap method for nulling.

Just because you can make any shape doesn't mean that you should. The optimum or best shape for overlap method of coil is the soft 2D shape. I recommend you make this coil for tgsl.

[dbanner]

Do you reckon the dual beam adapter would work as per the schematic

Why,? Have you seen something on the schematic that looks suspect? It's essentially a chopping circuit. I only had a cursory look but maybe I'll check it out again in greater detail. In 1974, a dual channel scope would have been quite expensive.

[6666]

Maybe you can make a dual beam adapter. Allows you to use a single channel oscilloscope to display two signals simultaneously for comparison. Here's the link to one such circuit.

https://worldradiohistory.com/UK/Electronics-Today-UK/70s/Electronics-Today-1974-10.pdf

I'm sure there are other similar circuits out there. It's not the best, but if you just want to compare the phase difference and null for balancing, it should suffice. You may need a preamp for the RX signal for the above circuit.

Do you reckon the dual beam adapter would work as per the schematic

[mostafalesnar91]

Thanks,guys
is it possible?
the coil should be two identical circles,not two D
like the picture I put

[dbanner]

Maybe you can make a dual beam adapter. Allows you to use a single channel oscilloscope to display two signals simultaneously for comparison. Here's the link to one such circuit.

https://worldradiohistory.com/UK/Electronics-Today-UK/70s/Electronics-Today-1974-10.pdf

I'm sure there are other similar circuits out there. It's not the best, but if you just want to compare the phase difference and null for balancing, it should suffice. You may need a preamp for the RX signal for the above circuit.

[waltr]

It is better than No scope.
A dual channel scope is greatly desired so that you can compare two signals.
This is what is needed to adjust coil null and phase. One trace shows the TX waveform and the second the RX waveform. Then you can see the amplitude and phase relationship between the two signals.

[mostafalesnar91]

Does this scope help me????

[mostafalesnar91]

Ivconic is not here

About nulling - balancing coils;

So far i made a lot of coils...Also experimented a lot...
Max can you repeat me your final measurements when your coil is nulled?
First is good to know that aint no multimeter with which we can accuratelly measure induced voltage on RX coil. Yes we can have some approx. results but not quite accurate...Why? Most of multimeters have good response on low frequencies, but on higher not! Error level rises up as frequency rising.
That's why oscilloscope is unreplaceable in accurate measurements..
But....in case we dont have osci.- must use what we have..Simply as that.
I do have quite useable multimeter with 200mV range AC/DC...So when finishing nullling coil i usually gain 0.000 mV...On first glance this sounds like a perfect balanced coil! But, as we know from experience...it is almost imposiblle to absolute balnce coils, due many objective reasons.
Above mentioned nulling is measured without 15nF parallel to RX coil. When i add that capacitor, induced voltage rises up to 0.009mv in most of cases. In few cases it raised up to 0.012mV...Than i triead again to fine readjust null to obtain absolute zero...yet without succes...Quite expectable.
But, somethimes i am to lunatic about those things...i want to push more and more, so today i made experiment with one coil. I nulled it with attached capacitor 15nF parallel to RX. Final voltage was 0.008mV...
I figured way how to achieve absolute zero; i put (carefully chosen) few very small pieces of Al foil inside coil housing, covering few spots on coils.Must mention those pieces are not connected anyhow in coil setup. Those pieces actually play role of "foreign body" inside coil. By moving them slowly,carefully inside coil i found exact spots and gained absolute zero balnced coils!!!
Actaully those Al pieces provoked minor induction, enough just to balance coil to zero.Coil is finished., filled with mass.Drained...and now is ready for terrain work. I checked it with detector.....PERFECT!!!! I gained extra 2cm's on single coin!!! Stabillity is good as it was before. Discrimination also good...
What to say? Crazy experiment gave me crazy result!!
Now i am thinking other thing; so i put Al pieces - "coloured" metal...What should be if i put iron pieces ("non-coloured") instead Al???
Only way to find out is to make another coil and try. I am planing to do that tomorrow...
I do know what is all about....perfectly clear to me. But i would like to hear your opinions...?
Heh,heh,heh...!

P.S.
You should appreciate this! I gave up one of "master secret" here!

[mostafalesnar91]

About nulling - balancing coils;

So far i made a lot of coils...Also experimented a lot...
Max can you repeat me your final measurements when your coil is nulled?
First is good to know that aint no multimeter with which we can accuratelly measure induced voltage on RX coil. Yes we can have some approx. results but not quite accurate...Why? Most of multimeters have good response on low frequencies, but on higher not! Error level rises up as frequency rising.
That's why oscilloscope is unreplaceable in accurate measurements..
But....in case we dont have osci.- must use what we have..Simply as that.
I do have quite useable multimeter with 200mV range AC/DC...So when finishing nullling coil i usually gain 0.000 mV...On first glance this sounds like a perfect balanced coil! But, as we know from experience...it is almost imposiblle to absolute balnce coils, due many objective reasons.
Above mentioned nulling is measured without 15nF parallel to RX coil. When i add that capacitor, induced voltage rises up to 0.009mv in most of cases. In few cases it raised up to 0.012mV...Than i triead again to fine readjust null to obtain absolute zero...yet without succes...Quite expectable.
But, somethimes i am to lunatic about those things...i want to push more and more, so today i made experiment with one coil. I nulled it with attached capacitor 15nF parallel to RX. Final voltage was 0.008mV...
I figured way how to achieve absolute zero; i put (carefully chosen) few very small pieces of Al foil inside coil housing, covering few spots on coils.Must mention those pieces are not connected anyhow in coil setup. Those pieces actually play role of "foreign body" inside coil. By moving them slowly,carefully inside coil i found exact spots and gained absolute zero balnced coils!!!
Actaully those Al pieces provoked minor induction, enough just to balance coil to zero.Coil is finished., filled with mass.Drained...and now is ready for terrain work. I checked it with detector.....PERFECT!!!! I gained extra 2cm's on single coin!!! Stabillity is good as it was before. Discrimination also good...
What to say? Crazy experiment gave me crazy result!!
Now i am thinking other thing; so i put Al pieces - "coloured" metal...What should be if i put iron pieces ("non-coloured") instead Al???
Only way to find out is to make another coil and try. I am planing to do that tomorrow...
I do know what is all about....perfectly clear to me. But i would like to hear your opinions...?
Heh,heh,heh...!

P.S.
You should appreciate this! I gave up one of "master secret" here!

So,you say this method of ivconic is mistake!!!!

[kt315]

had catch up you now for the nose! ))) i was right buddy.

[mostafalesnar91]

i grasp you closed foil rx tx shields together in crossing points. the typical mistake.

a genius is someone who succeeds in this way