First Texas Fisher, Bounty Hunter, and Teknetics HELP

[Carl-NC]

That's where the assembly house was located when FTP bought it. I doubt it would cost much more to run it in the US because the labor needed to operate the lines is not much. But it would cost a lot to move it to the US.

[ivconic]

I wouldn't know those details if it weren't for too many crime movies... so that's how I found out that Juarez is the most crime-ridden city
in the world... assuming that's true.
Because I stopped believing Hollywood's view of the world and life a long time ago.
But it is certainly unusual for one city to be divided by an administrative line. It is not so common in the world.
However, Trump was (at least declaratively) right in one thing; jobs should be brought back home.
It has been tempting for decades to create capital on the basis of cheap deals in China, Taiwan, Korea etc.
But it leads to unemployment in one's own country.
I am not saying this to criticize others... I am lamenting the situation in my country.
There is a saying in our country: "A frog saw the horse being shod; so it raised its leg too!"
Local charlatans and ignoramuses, who have been running the local economy for a couple of decades, rushed to rewrite the Western model and
literally copy everything from the Western economy.
This led to disastrous consequences.
A simple example, inflation in the USA is not the same as inflation in Serbia.
Inflation in the USA is a normal phenomenon and an integral part of progress.
And inflation in Serbia is an indicator of the decline of the economy.
You cannot simply copy the model from one big country to such a small country.
Along with a million other differences that follow the whole story.
But the ignorant do not understand this.
Serbia was a "country of peasants", ie. a country with highly developed agriculture and animal husbandry.
Very high quality and natural food was produced. More than half was for export.
Today... almost everything is imported!
And the food prices are such that I seriously worry if we will survive!
Not to mention that what is imported is of the worst quality with a lot of poisons and pesticides.
Something that normal developed countries would not allow to cross their borders.
Elections are coming soon here as well.
The scum that has been in power for the last 10 years is probably the worst I can remember in my life.
I don't remember the good days, I only remember the bad and worse.
And we are successively moving towards an increasingly worse state.
The problem is that the system is so set up that you have no real opposition here.
Those from the "other side" are also thieves, scoundrels, human scum.
Who to vote for?
I am a total pessimist and see no light at the end of the tunnel.
We need a total reset!

[kt315]

why all i was been teached in University about the capitalism, 1979-84, later/now turned out to be clear truth?
'the capital is always seeking better conditions and sure goes there'. but America is the monster/hegemon and owner of the printing paper machine...
they can print money that they want... inflation? they will transfer it in another countries, limitrophes like Lietuva, Latvija etc.

[ivconic]

It is not such a big dilemma that the USA has such behavior, because capitalism by its nature cannot survive without the expansion and use of cheap resources and cheap jobs.
If they stayed within their borders, without looking into someone else's yard; very quickly they would either fail or have to urgently change the system.
(That time is coming, the era of change has begun).
A much bigger problem is globalism, that is, a problem that has spread to all other countries in the world.
And it developed in a completely wrong way.
Paradoxically... but if the USA decides to abandon capitalism and turn to a better social order; the rest of the world will remain in the problem of globalism for a long time.
Because they unsuccessfully copied and followed all the negative trends from Western societies.
Only those societies survive well that did not copy anyone, but developed according to their personal model.
Norway, Sweden, Luxembourg, Switzerland... and some other countries; today they look more and more like real Socialist societies and less and less like Capitalist ones.
I am all the more unhappy because I was born and lived for a good part of my life in a strongly organized socialist society.
And then we started importing Western models that were wrongly presented to us or that we misinterpreted.
Suddenly, individuals became "infected" with the desire to accumulate capital and separate themselves from the majority in wealth.
Suddenly a general decadence reigned. And that's how a class of thieves, socialist thieves in positions, was born.
And in the end, their actions ruined the until then very decent socialist society.
And when the people began to understand what was happening, that thief class then played the card of dividing people, on the basis of nationalism, on the basis of religion,
wherever it was convenient, and thus led to wars, destruction, misery.
The people suffered terribly, but thief class saved themselves and to this day, under different guises, they are among us and they rule.
And a paradoxical process is taking place, that the advanced are slowly leaving the classic capitalist system because of its flaws,
while the less advanced continue to rush towards pure capitalism in their ignorance of where it leads.

[Carl-NC]

This has veered off into politics. Please veer back to detector discussions.

[ivconic]

[ivconic]

You're right, I'm sorry.
Boredom takes its toll. Winter days are very boring and there is little to do.
Specifically on the current topic... I have a Eurotek Pro, just the detector box, a long time ago.
And I wanted to know the coil specs.
I think I even asked here on the forum a year or two ago...didn't get a helpful answer.
But patience pays off. The other day, a complete one came to me for service, again with the same famous problem with the foil keyboard.
Those foil keyboards are a very bad solution. There is no brand or model on which it does not suffer sooner or later.
The only "local" solution, with the lowest possible costs; is the removal of the foil and the installation of micro buttons.
But that doesn't matter now, the point is that I finally measured the stock coil.
TX= 4.2 ohms / 0.92mH
RX= 22.7 ohms / 8.68mH
I think it is 8" coil.
I did not measure the exact diameter with a ruler.
...
And with these coil specs, this topic finally made sense!

[ivconic]

But the story doesn't end there...unfortunately for me.
I got that detector in an exchange a couple of years ago.
Even then it had some damage.
The headphone jack was destroyed and the audio out transistor burned.
I connected the dots on the pcb so that the audio works without the presence of the jack and replaced the transistor with one in a TO-92 case and
finally got clear and loud audio.
Now that there is coil; for the sake of order, I also tried the detection.
Alas! Almost does not work, almost no detection.
Detection barely happens only when I literally rub a coin (or some other object) against the surface of the coil.
I checked the connections of the coil connector to the pcb, everything is fine, everything is correct.
Everything looks to me as if the TX transistor is also burnt.
It is SMD. I haven't measured or changed anything yet.
Because I didn't have time for further work at that moment.
But there is something else interesting that I noticed!
Both detectors are Eurotek Pro. But their cases are slightly different in design!???
Carl do you know anything about that?
Is it a Chinese copy, one of the two?
Or did Teknetics decide to change the design a bit in a new series?
The latter seems pointless to me, an unnecessary expense, to change the housing molds around such small and unimportant details?

[Carl-NC]

The design was changed at some point to use a proper 1/4" headphone jack and to surface mount the coil connector.

Here is the TX schematic. Test point 8-1 should be a pulse from the micro at ~19kHz.

[Carl-NC]

RX input:

[ivconic]

The design was changed at some point to use a proper 1/4" headphone jack and to surface mount the coil connector...

Thanks!
But have you payed attention on details on photos above?
On both there is 1/4" hp jack and on both coil connector is NOT surface mount, but connected with wires.
Differences are in volume and shapes of enclosure. So visible if you pay attention.
Click on photo to get hires one. Easier to spot the differences.

[ivconic]

No easy job for me.
TX is alright, I changed Q1 anyway. Same thing. I get nice sinus 9Vpp on the osciloscope.
Schematic of TX matches and everything looks fine.
However... RX is confusing, not matching the situation I have on pcb here.
U1 (supposedly TS971 on your schematic) is small SMD 6 pin chip.
I downloaded TS971 datasheet and there is no 6 pin package described in it.
Observing your schematic i can trace some of the traces.
Red goes through C1 (no L1 from schematic ???) directly to "+" (I assume it is "+") input of the 6 pin chip.
But Black is going only up to C4 and further I can't trace it.
If take that Red goes to pin 3. then previous to it logically should be pin 2.
At 6 pin case then on the other side there are pins 4, 5 and 6 by common logic.
So Black should be connected to pin 2. through the R3 (it is present and ok), L2 (not existing on pcb) and C4 (present and ok).
But the other side of C4 I am not able to trace with simple buzzer.
PCB does not look broken nor any trace too.
Just for the sake of experiment I added a wire connecting the othe end of C4 with pin 2.
Switching ON and after boot sequence it starts cackling like a chicken.
Before that , forgot to mention; with buzzer I discovered that pin 2. and pin 5. are connected togather (probably bellow the chip, since I can't see the trace) or the chip is burned and shorted those two pins.
So the problem is in RX.
Would be easier if I do know for sure what the 6 pin chip really is?
And its pin assignments.
That part is not matching with schematic.

[walter]

U1 =LTAFJ =LT6230CS6

[ivconic]

U1 =LTAFJ =LT6230CS6

That makes more sense now, thanks!
So, the ENABLE pin 5. is probably tied to pin 2. (V-) normally?
Or not?

[Carl-NC]

I don't know why the enclosures are different since they both have wired coil connectors. That was long before I arrived.

U1 (supposedly TS971 on your schematic) is small SMD 6 pin chip.

The LT6230 was used in the 1st-gen circuits. Then changed to the TS971. I don't have the old schematic.

But Black is going only up to C4 and further I can't trace it.

Black should be connected to ground. The (-) input of U1 should have an RLC circuit to ground, though I don't know the order. It's possible there is no L2 in the 1st-gen design.

Yes, you would tie /EN to V-.