TESORO GOLDEN SABRE

[Geo]

Hi Geo,
what about trip to Serbja ? Have you meet Ivconic there ?

And what about your TGS too , any news?

Best regards,
Max

PS: I've made the Vladimir's PCB design... and that way I've now also TGSL , that works good even without "right" components... I'm awaiting for new stuff to put on board...cause I run out of LF353 so I'm using now TL072 there.

Hi Max.
I did not meet Ivconic. I telephoned 2 times but he did not answer because he was afraid that I will take his TGS. I took wire for the coil but this time I dye the laboratory whenever I cannot make nothing. Beginnings December they will be all ready whenever I will also prepare the TGS and Barracuda that I have almost ready, and also I will begin the ATINY4
Regards

TGS

FOR IVCONIC


I finish my TGS in this week.
I used LM308 metalic, LF 442, LM 353, 2N2222, 2N2907, BF245C, nulling coils is OK(with scope), discrimination, notch filter, audio, ALL OK. Coil is 28 cm DD.


1 Euro detection at 36 cm in air
Small gold ring at 30 cm in air.


Very good detector, but the problem is when I swing the coil or the cable, a lot of sounds appear on speaker in ALL METAL mode and a few less in DISCRIMINATION mode.
Is impossible to use my detector in this conditions.
What happened here?
I need help,


Thanks

DIRCEU

Brazil SA.

[Max]

Not sure..?
Any other opinions on this?

Hi,
well.... I think that a metal box connected to gnd will shield part of signal thus preventing that its electrical component will enter the PCB. But is PCB noise coupling the real problem ? what about magnetic component ?

I think that the big problem is at coil. Also coil have shield but... shields have the gaps so they are not completely electrically shielded, then also they are exposed to elettromagnetic noise cause they work magnetically.

Magnetic and part of electric components of noise will enter the amplification chain then we'll hear them on speaker.

We cannot totally electrically or magnetically shield the coils: then we'll always have noise from cell phones near.

That's why I think that prospecting is a good reason to shut off the damn phone.

Best regards,
Max

[ivconic]

Hi Ivica,

Maybe Im wrong but I think that a good thing to avoid this, is usage of metal cases for detector housing instead of plastics.

Regards,
Darko

Not sure..?
Any other opinions on this?

[Darko]

Reffering cell phones...;

I noticed few times cell phone is making my TGSL absolute crazy from time to time...that's why i dont keep it with me on the field...?

Cell frequency varry from 860-900MHz here...? Must produce very strong field arround - since disturb md so significantly?
I have old Nokia 5210 with no so strong output...but heavy duty phone for sure! Good for hard conditions outdoor...
Anybody else noticed simillar interferences?

Hi Ivica,

Maybe Im wrong but I think that a good thing to avoid this, is usage of metal cases for detector housing instead of plastics.

Regards,
Darko

[Max]

No we didnt met here...
I was at home mostly. Day, Geo phoned me, i was on the field...not so far away from home, but didnt bring my cell phone with me...Marphy's law
BTW who was damn Murphy???

"Alice..alice...who the f.u.c.k. is Alice...!!?"

Regards!

Hi,
I think it's Murphy... there are plenty of theories about who (if real) is/was that Murphy ...

Someone talk about an aerospace engineer involved in some USAF tests... where , by default, things were wrong...

found on wikipedia:

"
According to the book A History of Murphy's Law by author Nick T. Spark, differing recollections years later by various participants make it impossible to pinpoint who first coined the saying Murphy's law. The law's name supposedly stems from an attempt to use new measurement devices developed by the eponymous Edward Murphy. The phrase was coined in adverse reaction to something Murphy said when his devices failed to perform and was eventually cast into its present form prior to a press conference some months later—the first ever (of many) conferences given by Colonel Stapp, The fastest man on earth. These conflicts (a long running interpersonal feud) were unreported until Spark researched the matter. His book expands upon and documents an original four part article published in 2003 (Annals of Improbable Research (AIR)[3]) on the controversy: Why Everything You Know About Murphy's Law is Wrong. From 1948 to 1949, a project known as MX981 took place on Muroc Field (later renamed Edwards Air Force Base) for the purpose of testing the human tolerance for g-forces during rapid deceleration. The tests used a rocket sled mounted on a railroad track with a series of hydraulic brakes at the end.
Initial tests used a humanoid crash test dummy strapped to a seat on the sled, but subsequent tests were performed by medical doctor John Paul Stapp, at that time an Air Force Captain. During the tests, questions were raised about the accuracy of the instrumentation used to measure the g-forces Captain Stapp was experiencing. Edward Murphy proposed using electronic strain gauges attached to the restraining clamps of Stapp's harness to measure the force exerted on them by his rapid deceleration. Murphy was engaged in supporting similar research using high speed centrifuges to generate g-forces. Murphy's assistant wired the harness, and a trial was run using a chimpanzee.
The sensors provided a zero reading, however; it became apparent that they had been installed incorrectly, with each sensor wired backwards. It was at this point that a disgusted Murphy made his pronouncement, despite being offered the time and chance to calibrate and test the sensor installation prior to the test proper, which he declined somewhat irritably getting off on the wrong foot with the MX981 team. In an interview conducted by Nick Spark, George Nichols, another engineer who was present, stated that Murphy blamed the failure on his assistant after the failed test, saying, "If that guy has any way of making a mistake, he will." Nichols' account is that "Murphy's law" came about through conversation among the other members of the team; it was condensed to "If it can happen, it will happen," and named for Murphy in mockery of what Nichols perceived as arrogance on Murphy's part. Another account credits Stapp with espousing it shortly afterwards during a press conference. Others, including Edward Murphy's surviving son Robert Murphy, deny Nichols' account (which is supported by Hill, both interviewed by Spark), and claim that the phrase did originate with Edward Murphy. According to Robert Murphy's account, his father's statement was along the lines of "If there's more than one way to do a job, and one of those ways will result in disaster, then somebody will do it that way." Other documents indicate that Robert A. Murphy himself changed his story several times on several different occasions, including on a lengthy radio station interview which survives[citation needed].
"

Others talk about old magazines and comics etc and many other theories.

One way or another the law is about: "What can go wrong, will go wrong"
That's about how things go sometimes in real world !

Best regards,
Max

[Max]

Reffering cell phones...;

I noticed few times cell phone is making my TGSL absolute crazy from time to time...that's why i dont keep it with me on the field...?

Cell frequency varry from 860-900MHz here...? Must produce very strong field arround - since disturb md so significantly?
I have old Nokia 5210 with no so strong output...but heavy duty phone for sure! Good for hard conditions outdoor...
Anybody else noticed simillar interferences?

Hi,
yes... I noticed too. In the range 0-2meters from coil my cell gives strong signal from time to time. Happens when data exchange occours between phone and phone-cells around... so it's not continuos noise but you can hear bursts of data in tgs output like when e.g. on TV shows someone leave phone on and then microphone cables or portable radio-mic unit get that noise. Happened to me also with MP3 in recording mode !

Depends also on phones... some seems having much stronger emission than others. Anyway... fundamental frequency means few... cause you get transients EM noise due to data bursts start and end that are like low frequency ringing.

I found that only way to avoid that is switching off phone or leaving it on but in the car.

On PIs it's all the same... if detector is sensitive I ear phone on output.... so I think it's a really common problem with all sensitive units.

Best regards,
Max

[ivconic]

Reffering cell phones...;

I noticed few times cell phone is making my TGSL absolute crazy from time to time...that's why i dont keep it with me on the field...?

Cell frequency varry from 860-900MHz here...? Must produce very strong field arround - since disturb md so significantly?
I have old Nokia 5210 with no so strong output...but heavy duty phone for sure! Good for hard conditions outdoor...
Anybody else noticed simillar interferences?

[ivconic]

No we didnt met here...
I was at home mostly. Day, Geo phoned me, i was on the field...not so far away from home, but didnt bring my cell phone with me...Marphy's law
BTW who was damn Murphy???

"Alice..alice...who the f.u.c.k. is Alice...!!?"

Regards!

[ivconic]

Otislasi epaneta.
Good morning..... How are you.
Long time to see me .... i know
Regards

Otisla si epa neka !
Ti kanis Geo? Kala ise?
Efige apo Servia.
Tie egine stin Belgradi?
Nikisa..?
Regards!

[Max]

Otislasi epaneta.
Good morning..... How are you.
Long time to see me .... i know
Regards

Hi Geo,
what about trip to Serbja ? Have you meet Ivconic there ?

And what about your TGS too , any news?

Best regards,
Max

PS: I've made the Vladimir's PCB design... and that way I've now also TGSL , that works good even without "right" components... I'm awaiting for new stuff to put on board...cause I run out of LF353 so I'm using now TL072 there.

[Geo]

Otislasi epaneta.
Good morning..... How are you.
Long time to see me .... i know
Regards

[strujas]

Vladimir I have tryed, but no results,The administrator has banned your email address, give me some other email

[ivconic]

Check Potentiometers quality! I had case that brand new 100K potentiometer ( i just bought it) was bad from a start. When connected on pcb i had totally lost of Discrimination!? Later when checked all i found out it was bad.
Again damn suppliers here....

Actually Strujas bought that one

[ivconic]

Hello there. when i bulded my TGS i had a very good results, untill i made NF amplifier with integral TDA. I lost my discrimination at small objects. Discrimination exists untill i turn potentiometar on max. I had -6.2V and now i have -5.9V, i returned MPSA13 and these rusults are with this Transistor. I checked all integrals, and FET transistors but results are bad as they where.Im interested in max range for TGS with 25cm sonde?

And what do you think i should do to remove this failure in my TGS?
I had a max range 80cm at larger objects.

Regards Dino :P

Hi Dino!
I never liked any of suggested audio NF amplifiers here. Original audio stage with MPSA or whatever transistor showed the best performances so far.
This is not about, just simply to amplify signal. It is quite different approach.
There are 2 basic amplifying principles: voltage amplifying and current amplifying. You just can not mix those priniples. My english is not so good here, for me to give detailed explanations on this. But it is easy to search internet and find some articles on this.
TGS has rather simple yet hard to mod audio! Keep it as it is for now.
You lost discrimination?
OK, for a start assure proper voltages; +8v and -6.xxv.
Further investigate arround Disc&GEB stage. Dont put 10K resistor parallel to 100K Disc pot, as earlier suggested. In most of cases you will loose disc.
Measure current draw. Must be 30-40mA with no detection and 50-60 with full detection, meaning loud audio.
Let's go step by step;
measure all those, assure all i suggested here and report...
Regards!